Are second life Lithium Batteries safe?

Are you considering repurposing battery cells and building your own Powerwall or similar Energy storage system?

We are going to take a look at what you must understand before starting a project of this type.

The Chemistry


Both of these chemistries are considered dangerous, and they should be avoided, especially in any second life application. And even more importantly in any residential application. There is a real risk of a short circuit, leading to thermal runaway. Both of these chemistries will be extremely difficult to extinguish. And may explode, and burn anything and everything around it down to ashes, Firefighters will not try to extinguish a Lithium Battery fire, as they know they have no option but to wait for the

The capacity loss of LiBs is generally considered to be linear, with end of life typically around 75% to 80% state of health (SoH) and the final end-of-life stage around 50% to 60% SoH. However, at some point a severe and potentially dangerous deterioration can occur and lead to an increased ageing rate. The time at which this occurs, referred to as the “knee,” is difficult to predict. It can occur at a higher SoH than expected, thereby increasing the risk of thermal runaway, internal short circuits, and joule heating, according to the report.

Lithium Iron Phosphate

Although it is possible for LFP to enter thermal runaway, it is very unlikely, and usually only happens when external heat is present, it can also happen when the cell is at 100% SOC and is supplied with a very high current, such as

What is Thermal Runaway?