Lithium Battery Fire Risks in Solar Systems
More and more Lithium-ion batteries are being installed in conjunction with solar power systems. Modern equipment have inherent capabilities to communicate with Lithium-ion battery Battery Management Systems (BMS) which allows the battery to dictate the operating parameters of the equipment connected to it. This allow various battery models and sizes to connect seamlessly with solar power equipment.
Furthermore more Lithium-ion batteries are retrofitted into existing systems.
Lithium-ion batteries installations for solar power systems often includes the more stable lithium iron phosphate (LiFePO4) battery type. While LiFePO4 batteries are less prone to catastrophic failure compared to other lithium chemistries, they are not immune to fire risk. Fire can be triggered by several factors:
- Legacy Equipment: Not all equipment support battery communication. Most Lithium battery manufacturers support battery functionality using static equipment settings. Static settings may not be able to cater for all operating scenarios especially to scenarios which may lead to battery overrun situations, leading to increased battery cell voltage an a resultant increases in call temperatures.
- Thermal Runaway: This occurs when a battery cell overheats, initiating a self-sustaining chemical reaction that generate extreme heat (up to 400 °C) and flammable gases. Causes include overcharging, physical damage or internal shorts. In solar systems, improper or faulty battery management systems (BMS), programming, faulty inverter behaviour or faulty wiring can exacerbate this risk.
- Electrical Faults: Solar Systems involve complex electrical connections. Faulty inverters, chargers or wiring can cause electrical shorts, sparking a fire which may ignite the battery.
- Environmental factors: Batteries stored in poorly ventilated or high-temperature environments, such as garages or sheds, are more susceptible to overheating. Unforeseen or unintentional risks may include direct sunlight or other heat source exposure which increase the fire risk. In some cases exposure to water, such as an open window through which rain can reach a battery or, in rare occasions, flooding, potentially triggering short circuits or violent chemical reactions that lead to fire. Insects can cause short circuits in batteries or inverters which trigger already mentioned factors leading to fire.
- Mechanical Damage: Physical impacts during installation or equipment handling can damage battery cells, leading to internal shorts and potential fires. This is particularly relevant to DIY solar setups where handling protocols may be less rigorous.
Once ignited, lithium-ion battery fires are notoriously difficult to extinguish. They can produce their own oxygen, rendering traditional smothering methods ineffective, and are prone to re-ignition due to residual heat. Compounding to this they release toxic gases like hydrogen fluoride, posing health risks to responders and occupants.
Manage the risk using a Lithium Battery Fire Extinguisher.