If the JK BMS is not turning on when first connected, follow these steps to troubleshoot and properly power it up.
1. Check the Wiring Connections
Ensure the balance leads are connected correctly
The B- lead should be connected to the main negative of the battery pack.
The balance wires must be connected in the correct sequence:
B0 (Black wire) → Main negative terminal of the first cell
B1 → Positive terminal of Cell 1
B2 → Positive terminal of Cell 2
B3 → Positive terminal of Cell 3
B4 → Main positive terminal of the battery pack
2. Verify Cell Voltages
Measure the voltage between each balance wire using a multimeter.
Ensure all cell voltages are within a reasonable range (typically 3.2V – 3.6V per cell).
If any cell voltage is missing or significantly different, the BMS may not power on.
3. Check the Main Power Connection
B- Wire (Main Negative): Ensure the thick B- wire is securely connected to the main negative of the battery pack.
P- Wire (Output Negative): This connects to the load/charger and should not be used for powering the BMS initially.
4. Manually Activate the BMS
Some JK BMS units require manual activation if they don’t turn on automatically.
Try plugging in a charger (even briefly) to the battery terminals to “wake up” the BMS.
Alternatively, hold down the power/reset button (if available) for 3-5 seconds.
If you dont have the power button, consider sourcing one
5. Check if the BMS is Drawing Current
Use a multimeter in DC current mode to check if any current is flowing through the BMS.
If the BMS is drawing zero current, it may indicate a wiring issue or a defective unit.
6. Test Communication with the App
Download the JK BMS App on a smartphone.
Turn on Bluetooth and try scanning for the device.
If the BMS does not appear, it is still off or not receiving power.
7. Inspect for Factory Sleep Mode
Some BMS units are shipped in a factory sleep mode, requiring a charger or an external power source to turn on.
8. Reset the BMS
If all else fails, disconnect all connections for 1-2 minutes, then reconnect everything carefully.
Final Check
Once the BMS powers on, verify that all cell voltages are detected correctly in the app.
If issues persist, check the BMS documentation or test with another BMS to rule out a faulty unit.
STILL NOT WORKING? Its probably in sleep mode
If the JK BMS is in sleep mode and does not have a power button, here are all possible ways to wake it up:
1. Connect a Charger to the Battery
Most common method: Connecting a charger to the battery terminals will usually wake up the BMS.
Plug a LiFePO4-compatible charger (or a power supply) into the battery’s main terminals (B+ and B-).
Even a brief connection (a few seconds) might be enough to turn the BMS on.
2. Connect a Charger to the Load Side (P+ and P-)
If charging via the battery terminals does not work, try connecting the charger to the load terminals (P+ and P-).
Some JK BMS models wake up when voltage is applied here.
3. Apply a Small Load Across P+ and P-
Some JK BMS units wake up when they detect a current draw.
Connect a small 12V load (e.g., a 12V light bulb or small resistor) across P+ and P- for a few seconds.
4. Jumpstart the BMS Using a Resistor or Wire
Take a resistor (~1kΩ – 10kΩ, 0.5W or higher) or a jumper wire and temporarily connect:
B+ (battery positive) to P+ (load positive)
B- (battery negative) to P- (load negative)
This creates a tiny voltage differential, which can wake the BMS up.
5. Disconnect and Reconnect the Balance Leads
Sometimes, disconnecting and then reconnecting the balance leads (B0-B4) in the correct order can trigger the BMS to power on.
Steps:
Disconnect the balance connector from the BMS.
Wait 1-2 minutes.
Reconnect it in the correct sequence (B0 → B1 → B2 → B3 → B4).
6. Use a Bench Power Supply to Apply Voltage to B+ and B-
If the BMS is completely unresponsive, try applying a small amount of voltage from a bench power supply.
Set the power supply to 12-14V, and briefly connect it to B+ and B-.
This simulates a charger and can often wake up the BMS.
7. Check for a Reset Pin on the BMS Board
Some JK BMS units have an internal reset pin or pads that, when shorted for a second, will wake the unit.
If comfortable opening the BMS case, check for labeled pads (like RST or SW) and try shorting them momentarily.
Final Step: Replace the BMS
If none of these methods work, the BMS might be defective or damaged. Testing with another BMS will confirm whether the issue is with the battery or the unit itself.
In today’s rapidly expanding energy storage market, Battery Management Systems (BMS) play a critical role in the health, safety, and performance of lithium batteries. Whether you are building a battery for a solar setup, electric vehicle (EV), or DIY energy storage system, choosing the right BMS is essential for managing battery performance, extending lifespan, and protecting against potential hazards.
This guide will delve into some of the most popular and well-regarded BMS options available in the market, including JBD, JK, and Daly, analyzing their features, reliability, and overall performance. We’ll also highlight the pros and cons of each system to help you make an informed decision based on your specific requirements.
What is a Battery Management System (BMS)?
A BMS is an electronic system that manages a rechargeable battery, such as lithium-ion or lithium iron phosphate (LiFePO4), by controlling key functions like charging, discharging, temperature, and overall safety. The BMS ensures that the battery operates within safe limits and helps prolong its lifespan by balancing the cells and protecting against issues like overvoltage, undervoltage, and overheating.
Popular BMS Brands Overview
The BMS market is vast, with many different manufacturers offering various models ranging from budget-friendly basic protection systems to advanced smart BMS options with sophisticated features like Bluetooth connectivity and active balancing. Let’s explore some of the most popular brands:
1. JBD BMS (Jiabaida BMS)
Overview: JBD is a popular choice among DIY battery builders and professionals alike. Known for its reliability and affordability, JBD offers a wide range of BMS products suitable for everything from small battery packs to large energy storage systems. It also features smart BMS options with Bluetooth, providing real-time monitoring and control through mobile apps.
Support for Victron, DEYE, Growatt and many other inverters.
An image of tTpopular JBD 200 amp 4s 12v BMS for LFP and Lithium BatteriesJBD-6s-22s-250A-2JBD ESS Smart BMS 16s 48V 200A LiFePO4JBD 300AMP BMS 24-48v
Key Features:
Available in 12.8V to 48V(51.2V) configurations, with various amp ratings.
Both Smart BMS with Bluetooth connectivity for monitoring battery status via an app and Regular BMS, set and forget!
Robust passive and active balancing models to keep cell voltages even.
Comprehensive protection against overcharge, over-discharge, and over-temperature.
Configurable parameters via PC software or mobile app.
Pros:
Cost-effective with very reliable performance.
Smart features like Bluetooth monitoring and mobile app control.
Flexible configuration options. Excellent Accuracy for SOC calculations
Available in high current ratings, suitable for large packs.
Regular firmware updates improve functionality.
Cons:
Slightly more complex to set up compared to simpler BMS units.
Bluetooth connection range can be limited.
Lack of detailed user manual support for first-time users.
Best For: JBD BMS is well-suited for both DIY enthusiasts and professional battery builders who need reliable, affordable BMS with smart monitoring features. Ideal for medium to large battery packs in solar, RV, and EV applications.
2. JK BMS (JiKong BMS)
Overview: JK BMS is one of the most advanced BMS systems on the market, especially popular among energy storage professionals. It is known for its robust features, including active balancing, high customization options, and detailed data monitoring. JK BMS is highly regarded for its accuracy, durability, and flexibility, making it ideal for large-scale and critical battery systems. Support for Victron, DEYE, Growatt and many other inverters.
JK BMS Inverter 200AJK-BMS_touchscreenB2A20S20P 200A Smart BMS JK
Key Features:
Active balancing (dynamic cell balancing) ensures cells are equalized during operation.
Bluetooth connectivity for real-time monitoring via a mobile app.
Configurable protection parameters for precise control over charging and discharging.
Software is good, but not perfect, and support has been poor in 2024 for the new model
Pros:
Excellent active balancing capabilities reduce cell degradation and extend lifespan.
Detailed monitoring and data logging for precise control.
Widely customizable for different applications off-grid systems, and commercial setups.
Rugged design with high current and voltage tolerance.
Good accuracy for professional energy storage projects.
Cons:
More expensive than basic BMS units.
Higher learning curve for those new to BMS systems.
Requires more time to set up and configure.
Quality of materials may be lower, than JBD
Software has been buggy.
Best For: JK BMS is the go-to choice for large-scale, critical energy storage applications where active balancing and precise control are necessary. It is ideal for professional setups, commercial energy storage, and high-performance EVs.
3. Daly BMS
Overview: Daly BMS is another popular option, especially in the DIY space, due to its affordability and basic functionality. Daly BMS is often used for simple battery systems that don’t require the advanced features seen in more expensive systems like JK or JBD. It offers basic protection for lithium batteries, making it suitable for small energy storage systems or low-demand applications.
Daly-4s-12v-SmartBMS 250A 300A 400A 500A
Key Features:
Basic protection: overvoltage, undervoltage, over-temperature, and short circuit protection.
Available in 12V to 48V configurations with various amp ratings.
Passive balancing for maintaining cell voltage consistency.
Compact design, easy to install, and cost-effective.
Pros:
Easy to buy
Simple to set up and use.
Basic cell balancing and protection features are sufficient for smaller setups.
Widely available with many options for different voltage and current requirements.
Cons:
Passive balancing is less efficient than active balancing.
Less suitable for large or high-performance battery systems.
Durability concerns for long-term use in critical applications.
Active Cooling is unreliable
Best For: Daly BMS is ideal for small-scale projects, DIY enthusiasts, and applications where basic protection is sufficient, such as small solar setups, electric bikes, or RVs. However, it may not be the best choice for large or critical energy storage projects.
4. PACE BMS
PACE BMS is designed to offer precise control and management over battery packs, particularly in scenarios where safety, durability, and advanced functionality are critical. It competes with other high-end BMS solutions like JK and REC, offering features that cater to both small and large battery systems. The focus is often on high voltage and high current capabilities, active balancing, and detailed monitoring.
PACE BMS is trusted in many server rack batteries, and is very similar to many other professional grade UPS and ESS storage BMS, with communication with Inverters and other parallel batteries one of the strengths of this product. Support for Victron, DEYE, Growatt and many other inverters.
BMS 300A 16S – PACEEX 51.2v
Key Features of PACE BMS:
Passive Balancing: Ensures cells within the battery pack remain balanced, improving the pack’s longevity and performance.
High Voltage and Current Support: PACE BMS is designed to handle larger battery packs, making it suitable for industrial energy storage systems and EVs.
Smart Monitoring: Bluetooth connectivity, Wi-Fi integration, and real-time monitoring through mobile apps and dedicated displays.
Scalability: PACE BMS supports a wide range of voltages and capacities, making it versatile for projects of various sizes.
CAN Communication: Allows integration into more complex systems and communication with other components, such as in electric vehicles or sophisticated solar setups.
Configurable Protection Settings: Advanced protection for overvoltage, undervoltage, over-temperature, and current surges, with configurable thresholds.
Pros of PACE BMS:
Advanced Features: PACE BMS offers high-end features like balancing, real-time monitoring, and CAN communication, making it suitable for professional or industrial-grade systems.
High Reliability: It is built with a focus on safety and durability, ensuring optimal performance even under demanding conditions.
Great Scalability: Suitable for both small and large battery packs, offering flexibility across different applications.
Detailed Monitoring: Real-time feedback on battery health and performance ensures better maintenance and control.
Cons of PACE BMS:
Higher Cost: PACE BMS tends to be on the more expensive side compared to options like Daly or JBD, which may not make it ideal for DIY enthusiasts or small-scale projects.
Complexity: Due to its advanced features and configuration options, PACE BMS has a steeper learning curve and may require technical knowledge to set up and manage effectively.
Overkill for Simple Systems: For small or low-demand projects, PACE BMS may offer more features than necessary, which could result in unnecessary costs.
Best For:
PACE BMS is ideal for large, complex energy storage systems, electric vehicles, or any application that demands high reliability, precision, and detailed monitoring. Its advanced features and robust safety mechanisms make it a top choice for critical systems where performance and safety are paramount.
5. Other Popular BMS Options
Overkill Solar BMS: Specifically designed for DIY solar energy storage systems, Overkill Solar BMS is known for its user-friendly interface and detailed monitoring features. It offers Bluetooth connectivity and a built-in display for real-time stats, making it a favorite among home solar system installers. Overkill uses modified versions of the JDB BMS, in some cases the same BMS.
REC BMS: One of the high-end options, REC BMS, is designed for advanced applications requiring detailed control, real-time data, and integration into large, complex systems. It supports both passive and active balancing and is highly customizable, often used in commercial energy storage projects.
Lacks advanced features like active balancing, not DIY friendly
Commercial scale solar setups, low-voltage energy storage systems
REC
Active balancing, high customization, detailed monitoring
Highly customizable, integrates into large systems, active balancing
Very expensive, complicated setup overly complex
Large commercial projects, grid-connected systems, high-end EV setups
Final Thoughts: Which BMS is Right for You?
When it comes to selecting a BMS, the right choice depends on your specific project requirements. Here’s a quick summary to help guide your decision:
For DIY enthusiasts or small battery systems: JBD offers the most budget-friendly option with basic protection features. It’s ideal for simple projects like e-bikes or small solar setups.
For advanced DIY and professional setups: JBD and JK BMS is a great middle-ground option, providing smart features like Bluetooth monitoring, good balancing, and flexibility in configuration. It’s a solid choice for medium to large battery packs.
For large-scale or critical energy storage systems: PACE BMS is the gold standard, offering active balancing, high current handling, and extensive monitoring capabilities. It’s perfect for large energy storage projects, EVs, and commercial applications where reliability and performance are paramount.
Ultimately, the best BMS for your needs will depend on the complexity and scale of your project, as well as your budget. Each BMS option has its strengths, and understanding your specific requirements will help you choose the most suitable one for your system.
Ready to Take Your Energy Storage to the Next Level?
At LiFePO4 Australia, we specialize in helping you choose the best components for your battery systems. Whether you’re looking for a high-end BMS or just starting out with a basic battery pack, we’ve got you covered with expert advice and top-tier products. Contact us today to learn more about our range of BMS options and how we can help you build the perfect battery system!
AS/NZS 5139-2019 Compliance Guide for a 15kWh, 51.2V, 300Ah Lithium Battery with LiFePO4 Cells
All of our LiFePro Batteries are designed to comply with IEC62619 for installation to AS/NZS3001.2:2022 standard. Our Lithium batteries are designed to comply to IEC62619 and therefore can usually be installed in most applications. We are currently working on the application and certificate of IEC62619 for a number of our batteries. You can reach out to find out more by calling us on (07) 4191 6815
Compliance vs. Certification
Compliance:
When a battery complies with IEC 62619, it means that the battery has been designed and manufactured to meet the requirements and criteria set out in the IEC 62619 standard.
This compliance could be based on internal testing and assessments conducted by the manufacturer to ensure that the battery meets the necessary safety and performance specifications outlined in the standard.
Certification:
Certification, on the other hand, involves a formal process where an accredited third-party testing organization tests and verifies that the battery meets the IEC 62619 standard.
This process includes rigorous testing under controlled conditions and results in an official certificate or mark that indicates the battery has been independently verified to meet the standard.
Certification provides a higher level of assurance and credibility to customers and regulators, as it involves independent validation.
Why Certification Matters
Market Acceptance: Many markets, industries, and customers require certified products to ensure safety and reliability. Certification can be a requirement for selling products in certain regions or for use in specific applications.
Liability and Compliance: Certification can protect against liability and regulatory issues, as it demonstrates that the product has been independently verified to meet recognized safety standards.
Customer Confidence: Certification provides customers with confidence in the quality and safety of the product, which can be a key differentiator in the market.
1. Introduction
AS/NZS 5139:2019 sets the standards for the safe installation of battery energy storage systems (BESS) in Australia and New Zealand. Compliance with this standard ensures the safety and reliability of your lithium battery system. This guide will help you meet these standards for your 15kWh, 51.2V, 300Ah lithium battery containing LiFePO4 cells. To ensure the safety and compliance of your 15kWh, 51.2V, 300Ah lithium battery system, it’s important to adhere to both AS/NZS 5139:2019 and additional regulations specified in AS/NZS 3000:2018
2. System Design
2.1 Battery Specification
Capacity: 15kWh
Voltage: 51.2V
Current: 300Ah
Chemistry: Lithium Iron Phosphate (LiFePO4)
2.2 Key Components
Battery Management System (BMS)
Inverter/Charger
Safety Enclosure
Circuit Protection Devices (Fuses/Breakers)
Cabling and Connectors
3. Installation Site Requirements
3.1 Location
Battery Location & Restrictions:
Install the battery system in a well-ventilated, cool, and dry area.
Avoid direct sunlight and ensure the location is away from flammable materials.
Batteries cannot be installed in restricted locations such as near gas appliances and gas cylinders. Specifically, there are exclusion zones for electrical installations near gas relief vent terminals to prevent ignition hazards (AS/NZS 3000:2018, Section 4.18) (GSES).
Ventilation and Environmental Requirements:
Ensure the installation site provides adequate ventilation to avoid overheating and accumulation of gases. The location should maintain temperatures within the limits specified by the manufacturer and control humidity levels to prevent condensation (Standards.govt.nz) (GSES).
3.2 Access and Clearances
Ensure clearances around the battery system for maintenance and ventilation as specified by the manufacturer.
Allow at least 600mm clearance around the battery enclosure.
3.3 Environmental Conditions
Install the system within the environmental conditions specified by the manufacturer (e.g., temperature, humidity).
4. Safety Considerations
4.1 Battery Enclosure
Use a non-combustible, weatherproof enclosure with an IP rating appropriate for the installation location (e.g., IP65 for outdoor installations).
The enclosure should have ventilation to prevent the accumulation of gases.
4.2 Fire Safety
Install fire-resistant barriers as required.
Maintain a safe distance from ignition sources.
Ensure the system is equipped with a fire suppression system if required by local regulations.
Fire Safety and Hazard Protection:
Install fire-resistant barriers and maintain safe distances from potential ignition sources. A fire suppression system may be required depending on local regulations (Smart Energy Council)(GSES).
4.3 Emergency Shutdown
Provide an accessible emergency shutdown switch.
Ensure clear labeling and instructions for emergency procedures.
Documentation should include detailed installation, operation, and maintenance instructions, along with clear labeling for emergency shutdown procedures (Standards.govt.nz) (Clean Energy Council).
5. Electrical Installation
5.1 Circuit Protection
Install DC fuses or circuit breakers appropriately rated for your battery system to protect against overcurrent conditions. Proper cable sizing is essential to minimize voltage drop and prevent overheating (Standards.govt.nz) (GSES).
5.2 Cabling
Use cables rated for the maximum current and voltage of the battery system.
Ensure cables are correctly sized to minimize voltage drop and heat generation.
Secure and protect cables against physical damage.
5.3 Earthing and Bonding
Earth the battery system according to AS/NZS 3000:2018.
Ensure all metallic parts are bonded to prevent electrical shock hazards.
5.4 Inverter/Charger Integration
Connect the battery system to the inverter/charger according to the manufacturer’s instructions.
Ensure the inverter/charger is compatible with the battery’s voltage and current specifications.
6. Battery Management System (BMS)
6.1 Functions
Overcharge/Over-discharge Protection: The BMS monitors the state of charge and prevents the batteries from being overcharged or excessively discharged, which can damage the cells and reduce their lifespan.
Temperature Monitoring and Control: The BMS tracks the temperature of the cells and the environment to prevent overheating. It can shut down the system or reduce the charge/discharge rates if temperatures exceed safe levels.
Cell Balancing: The BMS ensures that all cells in the battery pack are charged equally, preventing any single cell from becoming a weak link and reducing the overall capacity and lifespan of the battery.
Communication: The BMS communicates with external systems like the inverter/charger to provide status updates, alerts, and control signals.
Sound Alarm: The BMS must be equipped with an audible alarm to alert users in case of critical issues such as overcharge, over-discharge, overheating, or any other condition that might lead to a hazardous situation. This is part of ensuring that the system can provide immediate alerts to prevent accidents and enable timely intervention.
6.2 Installation
Manufacturer’s Instructions: Follow the specific installation instructions provided by the BMS manufacturer. This includes wiring, sensor placement, and configuration settings.
Configuration: Set up the BMS to match the parameters of your battery system. This might involve setting voltage thresholds, temperature limits, and other protective settings.
7. Documentation and Labeling
7.1 User Manual
Provide a detailed user manual including installation, operation, and maintenance instructions.
7.2 Labels
Clearly label the battery system with the following information:
Manufacturer name and contact details
Model and serial number
Electrical ratings (voltage, current, capacity)
Safety warnings and emergency shutdown instructions
8. Testing and Commissioning
8. Testing and Commissioning
8.1 Pre-Installation Testing
Component Testing: Before installing, test each component (battery cells, BMS, inverter/charger, etc.) to ensure they are functioning correctly. This includes checking for proper voltage, current, and any manufacturer-specific tests.
8.2 Post-Installation Testing
Inspection: After installation, perform a thorough inspection to ensure all components are correctly installed, all connections are secure, and there are no signs of damage.
Continuity and Insulation Tests: These tests check that the electrical connections are correct and that there are no unintended paths for current that could cause short circuits.
Functional Tests: Verify that the BMS and protective devices (fuses/breakers) operate correctly. Simulate fault conditions to ensure they respond appropriately.
Inverter/Charger Operation: Check that the inverter/charger correctly charges and discharges the battery and that it communicates effectively with the BMS.
9. Maintenance and Monitoring
9.1 Regular Inspections
Conduct regular inspections to ensure the system remains in good condition.
Check for signs of wear, corrosion, or damage.
9.2 Monitoring
Use monitoring systems to keep track of battery performance and health.
Regularly check BMS data for any anomalies or alerts.
10. Compliance and Certification
10.1 Certification
Obtain certification from a qualified electrical inspector to ensure the installation complies with AS/NZS 5139:2019.
10.2 Documentation
Keep records of all installation, testing, and maintenance activities.
Ensure all documentation is available for inspection by regulatory authorities.
If you are looking for a reliable and efficient energy storage solution you might be wondering whether to choose lifepo4 or lead-acid batteries. Both types of batteries have their advantages and disadvantages, depending on your needs and preferences. In this article, we will compare lithium and lead-acid batteries in terms of performance, durability, cost, and environmental impact, to help you make an informed decision.
Performance
One of the most important factors to consider when choosing a battery is its performance, which includes its capacity, power, efficiency, and lifespan.
Capacity
The capacity of a battery is the amount of energy it can store and deliver. It is measured in amp-hours (Ah) or watt-hours (Wh). The higher the capacity, the longer the battery can run your appliances and devices.
Lithium batteries have a higher capacity than lead-acid batteries of the same size and weight. For example, a 100Ah lithium battery can provide 100Ah of usable energy, while a 100Ah lead-acid battery can only provide 50Ah of usable energy at best. This is because lithium batteries can be discharged up to 100% depth of discharge (DoD), while lead-acid batteries should not be discharged below 50% DoD to avoid damaging the cells.
Power
The power of a battery is the rate at which it can deliver energy. It is measured in watts (W) or amps (A). The higher the power, the faster the battery can charge and discharge, and the more appliances and devices it can run simultaneously.
Lithium batteries have a higher power than lead-acid batteries of the same capacity. For example, a 100Ah lithium battery can deliver up to 200A of continuous current, while a 100Ah lead-acid battery can only deliver up to 100A of continuous current. This is because lithium batteries have a lower internal resistance than lead-acid batteries, which means they can handle higher currents without overheating or losing efficiency.
Efficiency
The efficiency of a battery is the ratio of the energy output to the energy input. It is expressed as a percentage (%). The higher the efficiency, the less energy is wasted during charging and discharging.
Lithium batteries have a higher efficiency than lead-acid batteries. For example, a lithium battery can have an efficiency of up to 98%, while a lead-acid battery can have an efficiency of around 80%. This means that lithium batteries can store and deliver more energy from the same amount of solar input or generator output than lead-acid batteries.
Lifespan
The lifespan of a battery is the number of charge and discharge cycles it can undergo before its capacity drops below 80% of its original value. The higher the lifespan, the longer the battery can serve you before needing replacement.
Lithium batteries have a longer lifespan than lead-acid batteries. For example, a lithium battery can last up to 2000 cycles at 100% DoD, while a lead-acid battery can last up to 600 cycles at 50% DoD. This means that lithium batteries can endure more frequent and deeper cycling than lead-acid batteries without losing much capacity.
Durability
Another factor to consider when choosing a battery is its durability, which includes its resistance to temperature, vibration, and corrosion.
Temperature
The temperature of the environment where the battery is installed and operated can affect its performance and lifespan. Extreme temperatures can cause thermal stress, expansion, contraction, and chemical reactions that can damage the cells.
Lithium batteries are more resistant to temperature than lead-acid batteries. For example, lithium batteries can operate in a wider temperature range than lead-acid batteries, from -20°C to +60°C. They also have built-in battery management systems (BMS) that monitor and regulate the temperature of each cell to prevent overheating or freezing. Lead-acid batteries are more sensitive to temperature changes and require more ventilation and insulation to maintain optimal performance.
Vibration
The vibration of the vehicle or vessel where the battery is installed and operated can also affect its performance and lifespan. Excessive vibration can cause physical damage, loose connections, and internal short circuits that can reduce the capacity and power of the battery.
Lithium batteries are more resistant to vibration than lead-acid batteries. For example, lithium batteries are made of solid-state cells that are tightly packed and sealed in sturdy cases that prevent movement and leakage. They also have BMS that protect them from short circuits and overloads. Lead-acid batteries are made of liquid electrolyte and plates that are prone to spilling and sulfation under vibration.
Corrosion
The corrosion of the terminals and connectors of the battery can also affect its performance and lifespan. Corrosion can cause increased resistance, reduced conductivity, and poor contact that can reduce the capacity and power of the battery.
Lithium batteries are more resistant to corrosion than lead-acid batteries. For example, lithium batteries have stainless steel or brass terminals and connectors that are less likely to rust or oxidize than lead-acid batteries. They also have BMS that prevent overcharging and undercharging that can cause corrosion.
Cost
The cost of a battery is another factor to consider when choosing a battery. It includes the initial purchase price, the installation cost, the maintenance cost, and the replacement cost. But in 2024, its usually far cheaper per cycle to purchase a Lifepo4 battery. Usually 5-10 times cheaper or more.
Purchase Price
The purchase price of a battery is the amount of money you pay upfront to buy the battery. It is usually based on the capacity, power, and quality of the battery.
Lithium batteries have a higher purchase price than lead-acid batteries of the same capacity and power. For example, a 100Ah lithium battery can cost around $400-$600, while a 100Ah lead-acid battery can cost around $300-$600. This is because lithium batteries use more advanced and expensive materials and technologies than lead-acid batteries, but recently the competition of Lithium Iron Lifepo4 has lead to very similar prices
Installation Cost
The installation cost of a battery is the amount of money you pay to install the battery in your vehicle or vessel. It is usually based on the size, weight, and complexity of the battery.
Lithium batteries have a lower installation cost than lead-acid batteries of the same capacity and power. For example, a 100Ah lithium battery can weigh around 12kg and take up around 20L of space, while a 100Ah lead-acid battery can weigh around 30kg and take up around 40L of space. This means that lithium batteries are easier and cheaper to install than lead-acid batteries, especially in tight and limited spaces.
Maintenance Cost
The maintenance cost of a battery is the amount of money you pay to maintain the performance and lifespan of the battery. It is usually based on the frequency, complexity, and necessity of the maintenance tasks.
Lithium batteries have a lower maintenance cost than lead-acid batteries. For example, lithium batteries are maintenance-free and do not require any watering, equalizing, or cleaning. They also have BMS that monitor and regulate their performance and health. Lead-acid batteries require regular maintenance such as watering, equalizing, cleaning, and checking for corrosion and sulfation. They also need external regulators to prevent overcharging and undercharging.
Replacement Cost
The replacement cost of a battery is the amount of money you pay to replace the battery when it reaches the end of its lifespan. It is usually based on the lifespan, availability, and recyclability of the battery.
Lithium batteries have a lower replacement cost than lead-acid batteries. For example, lithium batteries can last up to four times longer than lead-acid batteries, which means they need to be replaced less often. They are also more widely available and recyclable than lead-acid batteries, which means they are easier and cheaper to dispose of.
Environmental Impact
The environmental impact of a battery is another factor to consider when choosing a battery. It includes the energy consumption, greenhouse gas emissions, waste generation, and resource depletion associated with the production, use, and disposal of the battery.
Energy Consumption
The energy consumption of a battery is the amount of energy required to produce, charge, and discharge the battery. It is usually based on the efficiency, lifespan, and capacity of the battery.
Lithium batteries have a lower energy consumption than lead-acid batteries. For example, lithium batteries can store and deliver more energy from the same amount of solar or generator input than lead-acid batteries due to their higher efficiency. They also need less energy to produce due to their longer lifespan and smaller size.
Greenhouse Gas Emissions
The greenhouse gas emissions of a battery are the amount of carbon dioxide (CO2) and other gases released into the atmosphere as a result of the production, use, and disposal of the battery. They are usually based on the energy consumption, energy source, and recycling rate of the battery.
Lithium batteries have lower greenhouse gas emissions than lead-acid batteries. For example, lithium batteries can reduce CO2 emissions by up to 50% compared to lead-acid batteries due to their lower energy consumption and higher recycling rate. They also use renewable energy sources such as solar or wind more efficiently than lead-acid batteries due to their higher efficiency.
The production and carbon costs of Lead Acid vs Lithium, are very hard to know, with some saying Lithium is much worse, and it’s true that mining lithium and Iron and the other metals required may have a higher carbon footprint, but if you are using the battery daily, these will eventually become less.
Cranking Amps compared
When comparing cranking amps between LiFePO4 (Lithium Iron Phosphate) and lead-acid batteries, there are some important distinctions:
LiFePO4 Batteries:
LiFePO4 batteries are more effective at delivering a large amount of current over a short period.
They are particularly suitable for applications where high cranking power is needed, such as starting engines or powering devices with significant initial current demands.
For instance, if you require a battery that can sustain a 40-amp device for two hours straight, LiFePO4 is an excellent choice
Lead-Acid Batteries:
Lead-acid batteries have been around for a long time and are commonly used in various applications.
While they have their advantages, such as being cost-effective, they are not as efficient as LiFePO4 batteries in terms of cranking amps.
Lead-acid batteries may struggle to deliver high current consistently over a short duration compared to LiFePO4 batteries.
In summary, if you prioritize high cranking power and need a battery that can handle substantial current demands, LiFePO4 is the way to go.
Published: December 26, 2023 | Updated: March 1, 2025
Lithium Iron Phosphate (LiFePO4) batteries have become a game-changer for off-grid enthusiasts, campers, and 4WD adventurers across Australia. Among the most popular options in 2025 are the Kings 12V 120Ah Lithium LiFePO4 Battery and the VoltX 12V 100Ah LiFePO4 Basic Lithium Battery. Both are affordable, reliable, and widely available, but they cater to slightly different needs. Let’s dive into an updated comparison to help you decide which one suits your setup best.
Kings 120Ah Lithium LiFePO4 Battery Review
The Kings 12V 120Ah Lithium LiFePO4 Battery, offered by 4WD Supacentre, remains a staple for those seeking a dependable, budget-friendly energy solution in 2025. Here’s what it brings to the table:
Key Features:
Capacity: 120Ah – offering a bit more juice than its VoltX counterpart.
Chemistry: LiFePO4 with prismatic cells (approx. 3000-cycle rating individually, though pack performance varies).
Weight: Approximately 15kg – lightweight compared to AGM alternatives.
Cycle Life: Rated for 2000+ cycles at 80% depth of discharge (DoD).
Battery Management System (BMS): Integrated BMS with thermal protection, overload management, and high/low voltage cutoff.
Connectivity: Supports up to 2 batteries in parallel or 4 in series.
Warranty: 12 months – very short but price reflects warranty
Price (2025 Estimate): Around AUD $499 (up from $449 in 2023 due to inflation and supply chain adjustments).
Pros:
Larger 120Ah capacity means more runtime for power-hungry setups.
Widely available through 4WD Supacentre’s extensive retail network, offering easy customer support.
Solid BMS ensures safety and reliability for off-grid use.
Great value for the price – still one of the cheapest LiFePO4 options per Ah in 2025.
Cons:
No Bluetooth or app-based monitoring – a basic battery with no frills.
12-month warranty is shorter than premium brands (though fair for the cost).
Some users report variability in long-term performance, possibly due to non-automotive-grade cells.
Best For:
Campers, boaters, or overlanders who need a reliable, no-nonsense battery for off-grid adventures without breaking the bank. In 2025, it’s still a top pick for those prioritizing capacity over advanced features.
Recommendation: We 100% recommend the Kings 120Ah for budget-conscious users who don’t need fancy extras. There are better batteries out there, but few match this price-to-performance ratio.
The VoltX 12V 100Ah LiFePO4 Basic Lithium Battery, sold by Outbax, continues to impress with its simplicity and performance in 2025. Here’s the latest rundown:
Capacity: 100Ah – slightly less than the Kings but still ample for most light applications.
Chemistry: LiFePO4 with A-grade prismatic cells.
Weight: Around 11kg – lighter than the Kings, making it easier to move.
Cycle Life: Advertised at 4000 cycles (though real-world testing suggests 2000-3000 cycles at 80% DoD).
Battery Management System (BMS): Integrated BMS protects against overheating, overcharging, and short circuits.
Connectivity: Officially not recommended for parallel/series connections, though some users report success with parallel setups.
Warranty: 36 months – a big step up from Kings.
Price (2025 Estimate): Around AUD $429 (up from $399 in 2023, reflecting market trends).
Pros:
Lightweight and compact – ideal for portable setups.
Longer 36-month warranty offers peace of mind.
Positive user feedback for reliability, especially with solar charging.
Outperforms AGM batteries in charging speed and weight.
Cons:
100Ah capacity limits its use for larger setups compared to the Kings.
No Bluetooth or advanced monitoring – like the Kings, it’s a basic battery.
Mixed messaging on parallel/series connections could confuse users.
User Feedback (Updated for 2025):
Richard B. (Adelaide, SA): “Still faultless after 18 months. Runs my 40L and 60L fridges for days via solar. Best bang for buck in 2025.”
Anonymous (VIC): “Perfect for my off-grid cabin. Charges fast and weighs next to nothing compared to my old AGM.”
Tom H. (QLD): “Outlasts my old lead-acid by miles. Two years in, and it’s still going strong.”
Best For:
Light off-grid applications like small fridges, LEDs, or solar-powered setups where portability and warranty matter more than raw capacity.
Head-to-Head Comparison (2025)
Feature
Kings 120Ah
VoltX 100Ah
Capacity
120Ah
100Ah
Weight
~15kg
~11kg
Cycle Life
2000+ cycles
2000-3000 cycles
BMS
Yes (basic)
Yes (basic)
Connectivity
2 parallel / 4 series
Not recommended
Warranty
12 months
36 months
Price (2025)
~AUD $499
~AUD $429
Availability
4WD Supacentre (online and retail stores)
Outbax (online-focused)
Key Differences in 2025:
Capacity: Kings wins with 120Ah vs. VoltX’s 100Ah – a 20% edge for bigger loads.
Weight: VoltX is lighter by 4kg, a bonus for portability.
Price: Kings is slightly more expensive, but you get more capacity per dollar.
Support: Kings’ physical stores offer an edge over VoltX’s online-only model.
Which Should You Choose in 2025?
Choose Kings 120Ah if:
You need more capacity for larger fridges, inverters, or multi-day trips.
You value in-person support and availability at 4WD Supacentre locations.
Budget is tight, and you’re okay with a shorter warranty.
Choose VoltX 100Ah if:
Portability and lighter weight are priorities.
You want a longer warranty for peace of mind.
Your setup doesn’t demand more than 100Ah (e.g., small solar or camping rigs).
Final Thoughts
In 2025, both the Kings 120Ah and VoltX 100Ah LiFePO4 batteries remain solid choices for budget-conscious Aussies ditching lead-acid batteries. Neither offers Bluetooth or premium features, but they deliver where it counts: reliable power at a fair price. Kings edges out for capacity and retail presence, while VoltX shines with its warranty and portability.
For most casual users, the Kings 120Ah is our top pick unless the VoltX’s lighter weight or longer warranty sways you. Either way, you’re getting a dependable LiFePO4 battery that’ll outlast AGM options every day of the week.
The 200MW/400MWh battery energy storage system (BESS) is live in Ningxia, China, equipped with Hithium lithium iron phosphate (LFP) cells.
Established 3 years ago in 2019 is already ramping up to a target of more than 135GWh of annual battery cell production capacity by 2025 for a total investment value of about US$4.71 billion.
The project was connected to the grid earlier this month, through a system integrator called ROBESTEC, about which little information appears publicly available. However, it is understood that although Hithium makes and provides complete BESS solutions as well as cells, in this case, it was the cell supplier.
200MW/400MWh HITHIUM LFP BESS in China
The facility stores energy at times of abundant generation from solar PV and wind, putting it into the grid during times of peak demand. It will also help regulate grid frequency.
If you are interested in these new 280AH cells, which Hithium and CATL currently can produce specifically for ESS use, let us know, as we have access to the cells when the demand is slightly lower. As these are actually in high demand for commercial applications, and they technically are hard to get for the DIY community.
it’s expected this giant LFP battery will cut CO2 emissions by 501,000 tons per year
Hithium specializes in the R&D, production, and sales of LFP energy storage batteries and systems. With strong customer orientation, they are committed to providing safe, efficient, clean, and sustainable energy storage solutions for the world. Hithium now has over 4400 employees globally including over 1000 R&D engineers with extensive experience in energy storage. With a planned 4.71 billion USD total investment and 1,400,000m2 factory space to achieve 135GWh production capacity of the energy storage battery in 2025.
Hithium-280ah-LFP280 12000 Cycles Storage Grade
Hithium_280ah_test_results
We delivered these cells in 2022 to a few customers and currently have a small shipment arriving again in February 2023. As they are an unknown brand to many customers, we haven’t ordered large quantities, because many customers still want EVE, CATL, LiShen, CALB, and various other brands they have heard of. It’s just not a well-known brand,
In the past was a bad thing, But with this type of new technology, sometimes it’s a great thing to get in early while you can.
The 12v solar panel market in Australia is about as bad as Aliexpress. Advertised panel outputs are grossly exaggerated, usually by 200-300%.
This post will be short and sweet, but some very simple math allows us to work out rough outputs from the panels available on eBay and even reputable retailers such as 4×4 Supacentre and online marketplaces such as www.catch.com.au.
A solar panel is usually something like 15-18% efficient in the 12v marketplace. It is extremely rare that they will actually output 20% or higher and if they do, they are probably 10x times more expensive than what you are looking at paying on the online marketplaces.
An example of what to expect from an eBay 350w solar panel is probably something like 80-120W. If you work out that 1000w of sunlight falls per metre squared that is STC and the panel is 1270mm x710mm and area of about 0.9m2. You can multiply that by 0.15 (15%) to get the wattage (if you need the calculation, do a google search). So, anyhow 0.9 x 0.15 is 135w. Now add in the NOCT rule of thumb, reduce that number by about a quarter and you will get 101w of power from that solar panel under normal operating conditions.
Given that you are paying about $170 for that panel. You are actually paying far too much for those solar panels you buy online and losing valuable roof space as a consequence.
Some people have caravans and off-grid requirements, so recently people have been looking to the house panel marketplace, this is a better option but only if you have the space available to install that size panel, and it also means your voltage may increase, which is fine as long as you take that into consideration.
It is illegal in Australia to work on any DC electrical system or panels with a voltage higher than 50V DC. This means you need to ensure you don’t run the panels in series of anything higher than that number unless you are a licensed electrician with the appropriate qualifications.
There are some exceptions to the marketplaces with Vendors such as Renogy. They actually do offer a more realistic wattage for their products, of course, you should still take roughly a quarter off the advertised wattage, because of the NOCT (normal operating conditions) rule. But at least you know what you are actually buying.
We will soon create a buyers guide and even list some good quality products on our website, so you don’t have to get ripped off buying completely rubbish claims made by online retailers.
Recently we watched Will Prowse review a OEM battery that we can and have been able to source in small quantities for some time, one of our trusted suppliers sent us one of these Batteries for review last year, this battery is a made-to-specification battery by one of the largest LIFEPO4 drop-in replacement manufacturers in China. You probably have some questions you want to know the answer about China and the Lithium drop-in replacement industry, because its really hard to know who is making and selling what. And its an eye opening journey.
Over the past few years, a few of the OEM Battery suppliers have come up with some reliable and high quality drop-in replacements. This is one of the reasons Will has only recently discovered these better quality OEM batteries. Because they have been a work in progress, as each company gets a little better, so do the batteries they produce.
If you think, it’s actually in the best interest of both the consumer and the manufacturer to make a battery that does work and doesn’t fail. The competitive nature of business drives the improving product all the time.
We have been testing batteries like this since 2015. And they have been available in a similar form since about 2014 from these manufacturers.
What has happened is that the product has matured, they have got to the point where the BMS is very reliable, and the cells are better than what most people need.
To find out why we won’t be importing this Weize 12V 100Ah LiFePO4 Battery in bulk read along further
Questions
Q. Can we get this in 50ah, 100ah, and 200ah capacity from the same manufacturer? A. Yes, we can
Q. Will we be ordering these into stock? A. No, we won’t, because there are too many brands of 12v 100ah drop-in, already on the market, and we would prefer to only bring in products we love and recommend for our customers.
Q. How much would we charge for this? A. Not as much as you might think, being Amazon is very competitive, the price of this is $350-450USD.
Lets do some quick math. based on the 2 prices $350USD and $450USD.
As you can see, there is no real business case for importing these into Australia. In fact they are already here, just labelled with a different brand. I know these are here in the $600-1000 range already.
It does make you wonder, should you buy a $400 eBay battery or should you buy a $2000 Enerdrive? In my view, I would buy somewhere in the middle, but I also build my own batteries which I prefer, as I can choose which cells I use, and which BMS I use, and that is exactly why we at Lifepo4 Australia choose to use the EVE and Ganfeng lithium cells primarily, because they are both A grade products, and they both use Australian Lithium inside them.
I don’t know about you but if Victron would just release a 100ah battery for $600-800, they would destroy every other battery retailer in one go. As long as it had 4 Series and 4 parallel, with an easy to use management software for when it’s used in various configurations. Victron would absolutely own the market.
1. China – CATL 2. South Korea – LG Chem 3. Japan – Panasonic
These 3 Brands enjoyed a combined EV battery market share of 68%, according to Goldman Sachs’ estimates in 2020/21 FY.
#1 CATL – Contemporary Amperex Technology Co. Limited, abbreviated as CATL, is a Chinese battery manufacturer and technology company founded in 2011 that specializes in the manufacturing of lithium-ion batteries for electric vehicles and energy storage systems, as well as battery management systems.
#2 LG Chem Ltd often referred to as LG Chemical, is the largest Korean chemical company is headquartered in Seoul, South Korea. first established as the Lucky Chemical Industrial Corporation, which manufactured cosmetics. It is now solely a business-to-business company.
#3 Panasonic – Famous around the world, a japanese conglomorate who has been enourmously successful for decades #5 BYD – The newest entrant here, Build YOUR DREAMS is an AMAZING COMPANY THAT IS GOING TO BE ONE OF THE LARGEST COMPANIES IN THE WORLD WITHIN 5-10 YEARS #4 CALB
LiFePO4 SOC: Wondering how to care for your valuable new purchase? Learn the best ways to charge and discharge lithium batteries and how to maximize their lifespan using lots of important technical information, most importantly this chart below.
LiFePo4 SOC Chart Typical LiFePO₄ Cell Voltage vs. State of Charge (Resting)
SoC
Voltage (rest)
Notes
0%
~2.5–2.7 V
Deeply discharged — can degrade cell if held too long
10%
~2.90–3.05V
Often cited as ~3.0 V under no load
20%
~3.05–3.15 V
Some charts place 3.0 V closer to 10–15% instead
30%
~3.15-3.21 V
40%
~3.21–3.25 V
50%
~3.25–3.30 V
“Plateau” region can be quite flat
60%
~3.30 V
70%
~3.33 V
80%
~3.35–3.37 V
90%
~3.37–3.40 V
100%
~3.40–3.45 V
Resting after a charge that ends around 3.65 V under load
Important Factors
SOC from voltage alone is rough Because LiFePO₄ has such a flat discharge curve (especially from ~30% to ~80%), relying on voltage alone for an exact percentage can be misleading. A half-charged cell might only differ by ~0.1 V from a 70% charged cell.
Refer to the specific datasheet If you have a particular cell model (e.g., Winston, CALB, EVE, A123, etc.), look for a voltage–capacity chart in that manufacturer’s datasheet. It will usually show discharge curves at different C-rates and temperatures.
Use a proper Battery Management System (BMS) Most modern BMSs use coulomb counting (tracking how many amp-hours go in and out) combined with voltage readings and temperature sensors. This approach is more reliable than voltage alone for determining SoC.
Err on the side of caution To prolong cell life, it’s best to avoid the extreme low-voltage region (<2.8 V) and the extreme high-voltage region (>3.65 V under charge), even if the cell is technically capable of those voltages.
LiFePO4 Charge Voltages The correct charge voltage for a 3.2V LFP cell is 3.65V, although it is safe to charge them between 3.4V and 3.7V. Most users are interested in what these values translate to for systems of 12V and above.
Noninal Voltage
Manufacturers Stated Charge Voltage
Absolute Maximum
Recommended Charge Voltage
3.2v
3.65v
3.7v
3.55-3.6v
12.8v
14.6v
14.8v
14.2-14.4v
25.6v
29.2v
29.4v
28.4-28.8v
51.2v
58.4v
59.2v
57.6v-58.4v
To clarify the numbers in the chart above, we recommend a lower charge voltage out of an abundance of caution. While we still believe the manufacturer’s stated charge voltage is sufficient, extensive real-world data over the past 15-20 years has shown that lowering the charge voltage can enhance the lifespan of the cells. However, in most cases, it is advisable to use the Victron Profile in your chargers. Victron is highly respected in the industry and has a profound understanding of LFP chemistry and many other battery chemistries. They set their LFP charge voltage at 3.55-3.6V per cell.
Victron Recommends:
For a 12.8V LiFePO4 battery: Victron recommends setting the charge voltage between 14.2V to 14.4V. The float voltage is recommended to be set at 13.5V.
For a 25.6V LiFePO4 battery: Victron recommends setting the charge voltage between 28.4V and 28.8V. The float voltage should be set at 27V.
For a 51.2V LiFePO4 battery: Victron recommends setting the charge voltage between 57.6V and 58.4V. The float voltage should be set at 54V.
Lithium battery prices are slowly changing from obscenely expensive to cheaper than traditional Lead Acid, and we at LiFePo4 Australia tend to find most users using them in Caravans, fifth wheels, RVs, and the like Vehicles while some are jumping into stationary off-grid systems.
Lithium Ferro (iron) Phosphate, also known as LiFePO4 or LFP, is a type of lithium-ion battery. Unlike the lithium cobalt batteries commonly found in cell phones and laptops, LFP batteries are more stable and less prone to catching fire. However, if an LFP battery is damaged, it can still be dangerous due to the energy stored in it.
LFP batteries offer several advantages over lithium cobalt batteries, including longer lifespan and better temperature stability, making them ideal for deep cycle applications. A Battery Management System (BMS) is essential for protecting LFP batteries. It disconnects the battery to prevent overcharging or excessive discharging, limits charge and discharge currents, monitors cell temperatures, and balances the charge across all cells. This balancing is similar to the equalization process in lead-acid batteries, ensuring all cells have the same state of charge.
DO NOT BUY a battery without a quality BMS such as the JBD and JK BMS
Below is the knowledge gained from experience, but also reading a large number of web articles, blog pages, scientific publications, and discussions with LFP manufacturers. which we are writing about here is by no means intended as the ultimate guide to LFP batteries, we hope this article will bypass the BS and give you solid tips on how to get the most out of Lithium IRON Phosphate
An image of the popular JBD 200 amp 4s 12v BMS for LFP and Lithium Batteries
We explained in our lead-acid battery article how that chemistry’s Achilles heel stays at a partial charge for too long It’s too easy to damage an expensive bank of lead-acid batteries in a few months by letting it sit at partial charge.
This is very different for LFP! You can let lithium-ion batteries stay partially charged forever without damage, LFP prefers to stay partially charged rather than full or empty, and for longevity, it is best to cycle the battery or let it sit partially charged. Any Lithium-ion batteries are currently what I would call the holy grail of batteries – with the right charging parameters you can almost forget there’s a battery. Maintenance. The BMS will take care of it and you can safely go cycling!
LFP batteries can also last very long. Most LFP batteries are rated for 3000 as a minimum cycles, with a full 100% charge/discharge cycle (we recommend 90%). If you do this every day, it gives you over 8 years of cycling! even longer when used in cycles less than 100%,
IN FACT, for simplicity, a linear relationship can be used: 50% discharge cycles mean twice as many cycles, 33% discharge cycles, and you can reasonably expect three times the number of cycles. A LiFePO4 battery also weighs less than one third that of a lead acid battery of similar capacity. It can withstand large charging currents (currently we recommend 0.5C) with most cells like the 280-330ah size to allow for fast charging, it’s sealed to prevent fumes and it has a very low self-discharge rate (3% per month or less).
Lithium-Ion vs. Lead Acid
As of 2024 a 12V 100Ah LFP battery can be found for as low as $299 AUD. The full 100Ah is usable, so 12.8 x 100 = 1,280-watt-hours of energy storage or just under $0.25c AUD per Wh of usable energy storage. Even of the best bang-for-buck really low quality deep cycle lead-acid batteries are currently about $200-300 for 12v 100Ah.
LEAD ACID PITFALLS
With lead-acid only 50% is safely usable without irreversable consequence. Lets calculate the usable watt hours 12v x 120ah x 50% = 770wh energy storage. That makes 249/60 = $ 0.32 AUD per Wh of usable energy storage.
The lifespan of a lead-acid AGM (Absorbent Glass Mat) battery when used occasionally in cycles can vary significantly based on factors such as depth of discharge, maintenance, and storage conditions. Generally, AGM batteries are known for their durability and longevity compared to other lead-acid types.
Cycle Life: AGM batteries can last between 300 to 700 cycles at 50% depth of discharge. Occasional use, where the battery is not deeply discharged each time, can extend the lifespan closer to or beyond the upper end of this range.
AGM (Absorbent Glass Mat) batteries typically last between 3 to 7 years, depending on usage and conditions. In optimal conditions, with proper maintenance, they can last over a decade. Key factors influencing their lifespan include the depth of discharge, operating temperature, and charging practices.
For occasional use, AGM batteries benefit from being kept in a partially charged state rather than being fully discharged. Regular charging, using smart chargers, and maintaining proper voltage can significantly extend their life. For example, maintaining a temperature range of 65 to 90°F and using temperature-compensated charging can help maximize their lifespan (Battery Skills) (Renogy) (OPTIMA Batteries) (Crown Power) (RV Talk).
Maintenance and Storage: Proper maintenance, such as keeping the battery charged and avoiding deep discharges, significantly affects lifespan. Storing the battery in a cool, dry place and ensuring it is not left in a discharged state will also help prolong its life
In summary, an AGM battery used occasionally in cycles can last anywhere from 3 to 10 years, depending on the depth of discharge, maintenance practices, and storage conditions.
Battery Bank Sizing for LFP
LFP (Lithium Ferro Phosphate) batteries have a usable capacity of about 90%, compared to lead-acid batteries which effectively provide only about 50% of their capacity. This allows you to size an LFP battery bank smaller than a lead-acid battery bank while achieving the same functional capacity. Typically, an LFP battery bank can be 55-60% the amp-hour size of a lead-acid battery bank.
Moreover, for longevity, lead-acid batteries should not be regularly discharged below 50% state of charge (SOC), whereas LFP batteries do not have this limitation. LFP batteries also have a higher round-trip energy efficiency compared to lead-acid batteries, meaning they require less energy to recharge after a discharge and can recover to 100% more quickly. This efficiency, coupled with the smaller required battery bank size, enhances overall performance.
As a result, sizing an LFP battery bank to 55-60% of the equivalent lead-acid bank size will not only match but often exceed performance expectations. Additionally, due to the higher efficiency of LFP batteries, you can reduce the size of the required solar panel array, further optimizing the system. This makes LFP batteries the superior choice in almost all scenarios, especially during periods of limited sunlight, such as dark winter days.
Beware of batteries connected in series!
Potential Issues When Connecting Lithium Batteries in Series
When connecting multiple lithium batteries in series, such as two 12V 100Ah batteries each with its own built-in Battery Management System (BMS), certain challenges can arise. For example, in a 24V 100Ah setup, if one battery is nearly empty and the other is almost full, and a load is applied, the empty battery’s BMS will shut down to prevent damage. This disconnection interrupts the entire battery bank, even if the other battery is still full.
Similarly, when charging both batteries simultaneously with a 24V charger, the fuller battery will reach its maximum charge first. Its BMS will then shut down to protect it, causing the entire battery bank to disconnect. If the batteries are out of sync initially, this issue will persist, preventing proper charging and balancing.
Unlike lead-acid batteries, which self-balance when charged, lithium batteries with independent BMS units do not naturally equalize their charge states. Therefore, it’s important to periodically sync the batteries by individually charging them with a 12V charger until both are fully charged. This ensures they start with the same state of charge, promoting balanced operation.
Understanding these dynamics is crucial when working with lithium-ion batteries, as their behavior differs significantly from lead-acid batteries. Proper management and periodic synchronization can help mitigate these issues and ensure reliable performance.
Temperature of LFP
But hold on! Is LFP really the perfect solution to all our battery issues? Not quite. LFP batteries also have their limitations. A major issue is temperature sensitivity: you cannot charge a lithium-ion battery below 0°C. Unlike lead-acid batteries, which can be charged in freezing temperatures, LFP batteries will not charge when it’s cold, although they can still be discharged with a temporary loss of capacity. The BMS (Battery Management System) should prevent charging in freezing temperatures to avoid damage, which can be a concern in the Australian climate.
High temperatures also pose a problem. Batteries age more quickly when used or stored at high temperatures. While temperatures up to 30°C are generally fine and even 45°C is manageable, anything higher accelerates aging and can significantly shorten the battery’s lifespan. To mitigate this, it’s crucial to store the battery in a shaded or cooled environment. (This also has implications for under bonnet use)
Another potential issue arises with charging sources that can deliver high voltage. If the battery becomes fully charged and the charging source doesn’t stop, the voltage will rise. If it rises too high, the BMS will disconnect the battery to protect it, potentially causing the charging source’s voltage to spike even further. This can happen with malfunctioning car alternator voltage regulators or small wind turbines, which depend on the battery to regulate their output. Such spikes can damage the LFP battery.
Additionally, the high initial purchase price of LFP batteries is a consideration. Despite these challenges, the benefits of LFP batteries often outweigh the drawbacks, making them an appealing option for many users.
How does a LiFePO4 battery work?
Lithium-ion batteries, including LiFePO4 (Lithium Iron Phosphate), are often described as “rocking chair” batteries. This term refers to the movement of lithium ions between the negative and positive electrodes during charging and discharging.
In the illustration, the red balls represent lithium ions. During discharge, these ions move from the negative electrode to the positive electrode. During charging, they move back in the opposite direction.
On the left side of the diagram is the positive electrode, made from iron phosphate (LiFePO4). This composition explains the battery’s name. Iron and phosphate ions form a grid that traps lithium ions. When the battery charges, lithium ions are drawn through the polymer membrane to the negative electrode on the right. This membrane has tiny pores that facilitate the passage of lithium ions. The negative electrode is made of a carbon lattice, which traps and holds the lithium ions.
When the battery discharges, electrons flow out through the negative electrode, and lithium ions move back through the membrane to the iron phosphate grid. They remain on the positive side until the battery is recharged. In a charged battery, lithium ions are stored in the carbon of the negative electrode.
In practical applications, lithium-ion cells consist of thin layers of alternating aluminum, polymer, and copper foils with chemicals adhered to them. These layers are rolled up like a jelly roll and encased in a steel container, similar to an AA battery. The 12-volt lithium-ion batteries available for purchase are made up of many such cells connected in series and parallel to increase the voltage and amp-hour capacity. Each cell provides about 3.3 volts, so connecting four in series yields 13.2 volts, making it a suitable replacement for a 12-volt lead-acid battery.
Charging an LFP Battery from solar
Charging LiFePO4 Batteries with Solar Charge Controllers
Most standard solar charge controllers can effectively charge lithium-ion batteries, such as LiFePO4 (Lithium Iron Phosphate) batteries, because the required voltages are similar to those for AGM (Absorbent Glass Mat) batteries, which are a type of sealed lead-acid battery. The Battery Management System (BMS) in LiFePO4 batteries ensures that the cells receive the correct voltage, preventing overcharging or over-discharging, balancing the cells, and maintaining cell temperature within safe limits during charging.
Charging Profile of LiFePO4 Batteries
LiFePO4 batteries have a characteristic charging profile that is easy to follow. The following points explain the process in detail:
Charge Voltage: The charging voltage for a 12V LiFePO4 battery is typically derived from the cell voltage. A single cell voltage is multiplied by four to get the approximate system voltage. For example, a single cell charge voltage is around 3.4V to 3.6V, so for a 12V system, it would be about 13.6V to 14.4V.
Charging Stages: LiFePO4 batteries are charged in two main stages:
Constant Current Stage: The battery is charged with a constant current until the voltage reaches the absorption level, typically around 14.6V for a 12V battery. During this stage, the voltage gradually increases.
Constant Voltage Stage: Once the absorption voltage is reached, the voltage is held constant, and the current gradually decreases. The battery is considered fully charged when the current drops to about 5% to 10% of the battery’s amp-hour (Ah) rating.
Efficiency: LiFePO4 batteries are more efficient than lead-acid batteries, meaning they require less energy to recharge after discharge. They also have a flat voltage curve, meaning the charge voltage does not change much with different charge rates.
Float Voltage: Unlike lead-acid batteries, LiFePO4 batteries do not require a float charge because they have a low self-discharge rate. If the charge controller cannot disable the float charge, set it to a low voltage (13.6V or less) to prevent actual charging.
Equalization: LiFePO4 batteries do not require equalization. If the charge controller has an equalization setting that cannot be disabled, set it to 14.6V or less so it functions as a normal absorption charge cycle.
High Voltage Protection: The BMS typically allows a maximum voltage of 14.8V to 15.0V before disconnecting the battery to prevent overcharging. There is no benefit to charging at higher voltages and doing so increases the risk of triggering the BMS protection and potential damage.
In summary, while LiFePO4 batteries are generally easier to manage and charge than lead-acid batteries, understanding their specific charging requirements and the role of the BMS is crucial for maintaining battery health and longevity. Properly configuring the solar charge controller to align with these requirements ensures optimal performance and safety.
Absorption time
There is a lot to be said for just setting the absorption voltage to 14.4V or 14.6V, and then stop charging once the battery reaches that voltage! In short, zero (or short) absorb time. At that point, the battery will be about 90% full. LiFePO4 batteries will be happier in the long run when they don’t stay at 100% SOC for too long, so this practice will extend your battery life. If you absolutely must have 100% SOC in your battery, absorb it will do! Officially, this is achieved when the charging current drops to 5% – 10% of the battery Ah value, i.e. 5-10 Amp for a 100Ah battery If you cannot stop absorbing the current, set the absorption time to about 2 hours and call Temperature compensation LiFePO4 Batteries do not require temperature compensation! Turn this off in the charge controller, otherwise, the charge voltage will be wildly turned off when it is very hot or cold. Check the voltage settings of the charge controller against actual voltage measured with a good quality DMM! Small changes in voltage can make a big difference during charging a lithium-ion battery! Change the charge settings accordingly!
Discharging an LFP Battery
Unlike lead acid batteries, the voltage of a lithium-ion battery remains very constant during discharge, making it difficult to guess the state of charge from the voltage alone. For a battery with a moderate load, the discharge curve seems LiFePO4 Discharge voltage vs. discharge voltage SOC LiFePO4 vs. SOC Most of the time during discharge, the battery voltage will be just around 13.2 volts. it was a really bad idea ™ to go below 20% SOC for a LiFePO4 battery. This has changed and the current LFP battery harvest will quite happily discharge down to 0% for many cycles. However, there is an advantage in pedaling less deep. It’s not just that going to 30% SOC will get you 1 / 3 cycles more than 0%, the battery will likely last more cycles than that. The hard numbers are, well, hard to find, but the cycle up to 50% SOC seems to show about 3 times the cycle life compared to .cycling 100%. Below is a table showing the battery voltage for a 12 Volt battery pack with respect to depth of discharge. Take these voltage values with a pinch of salt, the discharge curve is so flat that it is really difficult to determine SOC from voltage alone: small variations in load and accuracy of the voltmeter will negate the measurement.
LiFePo4 SOC Chart
% SOC
VOC
0.2C
100%
14.0 Volt
13.6 Volt
99%
13.8 Volt
13.4 Volt
90%
13.4 Volt
13.3 Volt
70%
13.2 Volt
13.2 Volt
40%
13.2 Volt
13.1 Volt
30%
13.0 Volt
13.0 Volt
20%
12.9 Volt
12.9 Volt
17%
12.8 Volt
12.8 Volt
14%
12.6 Volt
12.5 Volt
9%
12.4 Volt
12.0 Volt
0%
10.4 Volt
10.0 Volt
Storing lithium-ion batteries
The very low self-discharge rate makes it easier to store LFP batteries, even for longer periods of time. It is not a problem to put a lithium-ion battery away for a year, but make sure it is charged beforehand. Storing between 50% and 60% is ideal as the battery takes a very long time before self-discharge near voltage Storing batteries below freezing is fine even at very low temperatures than -40 degrees Celsius (which is the same in Fahrenheit) or even less! The electrolyte in LiFePO4 cells does not contain any water. Even if it freezes (which happens at around -40 degrees Celsius depending on the formulation), this is not the case. Allow the battery to warm up a little before discharging it again. This is fine at -20 degrees Celsius and above. When discharging at temperatures below freezing point, an obvious loss of capacity occurs, reversed when the battery rises above freezing point and has a slightly accelerated effect on aging. Storage at low temperatures is certainly much better than storage at high temperatures: the aging of the calendar slows down dramatically at low temperatures. Avoid storing them at 45 degrees Celsius and above, and try to avoid keeping them as full (or almost empty) as possible. If you need to store batteries for a long time, just unplug all cables from them. In this way, there can be no parasitic charges which slowly discharge the batteries.
The end of your lithium-ion batteries We can hear you gasp in horror; the idea that your precious LFP battery bank is no longer thrills you! Alas, all good things have to come to an end eventually. What we want to avoid is the premature (and perhaps spectacular) end of the genre, which makes us have to understand how lithium-ion batteries die. Many batteries consider a battery to be “dead” when its capacity drops to 80% of what it should be. Thus, for a 100Ah battery, its end comes when its capacity is reduced to 80Ah There are two mechanisms at work for the disappearance of your battery: cycling and aging. Each time you discharge and recharge the battery, it does a bit of damage and you lose a bit of capacity. But even if you put your precious battery in a beautiful, glass-enclosed sanctuary, never to be rolled, it will always come to an end.
LiFePo4 Lifespan
The latter is called lifespan. Calendar It is difficult to find reliable data on the calendar life of LiFePO4 batteries, very little is available. Some scientific studies have been conducted on the effect of extremes (temperature and SOC) on calendar life and these help set limits. What we gather is that if you don’t abuse the battery bank, avoid extremes and generally only use the batteries within reasonable limits, there is a maximum limit of about 20 years on calendar life. In addition to the cells inside the battery, there is also the BMS, which is made up of electronic parts. When the BMS fails, the battery will be too. ion batteries with a built-in BMS are still too new, and we’ll have to see, but ultimately the battery management system has to survive for as long as lithium-ion cells do. The processes within the battery conspire over time to coat the boundary layer between the electrodes and the electrolyte with chemical compounds that prevent lithium ions from entering and exiting the electrodes. The processes also bind lithium ions into new compounds chemicals, so they are no longer available to switch from electricity ode to electrode. These processes will happen regardless of what we do, but are very temperature dependent! Keep the batteries below 30 degrees centigrade and they are very slow. Go beyond 45 degrees centigrade and things speed up considerably! The # 1 public enemy for lithium-ion batteries is heat by far! The calendar life has more to offer and how quickly a LiFePO4 battery will age: the state of charge also has something to do with it. Bad at high temperatures, these batteries really, really don’t like to sit at 0% SOC and very high temperatures!
Also bad, although not quite as bad as 0% SOC, is sitting at 100% SOC and high temperatures for them. Very Low Temperatures As we discussed earlier, you cannot charge LFP batteries below freezing (and the BMS will not allow you to). It turns out that while it can be discharged below freezing, it also has an accelerated effect on aging. Nowhere near as bad as leaving your battery at a high temperature. However, if you are exposing your battery to freezing temperatures, it is better to do so while it is neither charging nor discharging and there is some gas in the tank (though not a full tank). In general, it is better to put these batteries away. a t around 50% – 60% SOC if they need to be stored longer. Molten Battery If you really want to know, what happens when a lithium-ion battery is charged below zero is that metallic lithium is deposited on the negative (carbon) electrode. , which end up puncturing the membrane and shorting out the battery (leading to a spectacular, unscheduled rapid disassembly event as NASA calls it, involving smoke, extreme heat, and most likely flames). Lucky for us this is something the BMS prevents from We move on to cycle life It has become common to get thousands of cycles, even at a full 100% charge-discharge cycle, with lithium-ion batteries There are some things you can do to maximize cycle life.
We talked about how LiFePO4 batteries work – they move lithium ions between electrodes It is important to understand that these are real physical particles, which have a size for them, are torn off one electrode and inserted into the other, each time the battery is charged-discharged This causes damage, particularly to the carbon of the negative electrode. Each time the battery is charged the electrode swells a little and thins again with each discharge. Over time this causes microscopic cracks. it is for this reason that loading a little below 100% will give you more cycles, as will discharging a little above 0%. Also, think of those ions as exerting “pressure,” and the extreme numbers of state of charge exert more pressure, causing chemical reactions that aren’t good for the battery. This is why LFP batteries don’t like being stored away. at 100% SOC, or float charge at (near) 100%. How quickly lithium ions are dragged here and there also has an effect on cycle life. Given the above, this shouldn’t come as a surprise. While LFP batteries are routinely charged and discharged at 1 ° C (i.e. 100 amps for a 100 Ah battery), you will see more cycles from your battery if you limit this to more reasonable values for lead-acid batteries Limit of about 20% of the Ah rating, and adhering to this limit for lithium-ion also has benefits for longer battery life. The last factor to mention is voltage, although this is really the BMS Lithium-ion batteries have a narrow voltage window for loading and unloading. Going outside this window very quickly will result in permanent damage and a possible RUD event (NASA talk, as mentioned before) in the upper area. For LiFePO4 this window is about 8.0V (2.0V per cell) up to 16. 8 Volts (4.2V per cell). The integrated BMS should be careful to keep the battery within these limits.
LFP Take-Home Lessons
Now that we know how lithium-ion batteries work, what they like and dislike, and how they ultimately fail, there are some tips to take away. We have made a small list below. If you’re not going to do anything else, please take note of the first two, they have by far the most effect on the overall time you have to enjoy your Li-ion battery! Paying attention to others will also help, to make the battery last even longer. above, for long and happy LFP battery life, in order of importance, you should pay attention to the following: Keep the battery temperature below 45 degrees centigrade (below 30 degrees if possible) – This is by far the most important! ! Keep charge and discharge currents below 0.5 ° C (preferably 0.2 ° C) Keep battery temperature above 0 degrees Celsius when discharging if possible – This is all located below is nowhere near as important as the first two Do not cycle below 10% – 15% SOC unless Do not float the battery at 100% SOC if possible Do not charge 100% SOC if you have none need That’s it! Now you too can find happiness and a full life with your LiFePO4 batteries!
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We have recently changed our naming of the cell grades. Due to misrepresenatation within the industry.