Lithium Battery Fires: Understanding the risk and what comes next

Given the growth expected in solar supported by home BESS the key risk management considerations are;

• fully understanding the deterioration of capacity relative to the number of charge cycles. Many we have spoken to had assumed wrongly that the ten year guarantee was not related  to cycle which it is.

• fully understand the deterioration of the battery over time given that the risk of thermal runaway in lithium graphite increases as the battery gets older / number of cycles increases.

• ensure that your insurers are fully aware of the battery type, its use, age, number of cycles and is happy to insure now and future as if insurers increase future pricing or limit cover given to lithium Graphite cells they may become uneconomic to insure and have consequences of mortgages and or bank funding. 

• additionally, understand dendrite buildup risk.

• if lithium graphite consider thermal monitoring to be able to close off if battery temperatures increased above agreed safe level

• consider end of life disposal safely and costs and factor in to budgets

• consider who would pay if a dispute on safety and replacement required.

While we were not specifically covering waste disposal re lithium graphite at the video call we are happy to give some views.

With lithium graphite being more widely used in cars, bikes, plant, tools, etc the increase in specialist disposal and recycling contractors continues. 

There is two points of note here.

• specialist firms know what they are doing so will have increased use and resources in the future.

• general waste contractors inc domestic waste contractors are being hit hard by people/firms wrongly disposing of lithium graphite batteries in to mixed general waste. Much more education should be done to educate communities to ensure safe disposal to professionals.

For general waste contractors they need to improve detection and segregation plus understand how to manage thermal runaway fires when they do happen to minimise surrounding damage and business interruption. There will be more innovation in this risk space in the future. 

Lithium Iron Phosphate (LiFePO₄, often shortened to LFP) cells are safer and more thermally stable than high‑energy NMC/NCA lithium‑ion chemistries, but they have lower energy density and are not immune from Thermal Runaway so whilst safer they are not safe.

Conditions That Can Trigger Fires

Although inherently safer, LiFePO4 batteries are not completely fireproof. Fires can occur under the following circumstances:

• Overcharging: Exceeding voltage limits can generate excessive heat, potentially leading to thermal runaway.

• Physical damage: Punctures, crushing, or severe impacts can cause internal short circuits, increasing fire risk. 

• Environmental stress: Prolonged exposure to high temperatures (e.g., above 60°C) or direct fire can compromise safety. 

• Poor quality components: Batteries without proper Battery Management Systems (BMS) or with manufacturing defects are more susceptible to overheating and fire.

Be concerned once cell temperatures approach or exceed about 60–80°C for prolonged periods and urgently concerned above ~150–200°C where thermal‑runaway reactions commonly initiate; immediate isolation, cooling, and evacuation are required if temperatures climb toward 200°C or higher