When LiFePO4 batteries are charged at extremely cold temperatures (below 0 degrees Celsius), there is a potential loss of capacity. For example, a 12V 100Ah LiFePO4 battery may only deliver 90Ah, 80Ah, or even 70Ah at freezing temperatures, depending on how cold it is. This is natural to LiFePO4's chemistry and is only temporary. When the battery gets hot, it will return to full capacity. At 0°C, the CLI100-12 battery (12V 100Ah) provides about 80 amperage hours. At -20°C, the capacity the battery can provide drops to about 70 amp hours. Charging a lithium iron phosphate battery at freezing temperatures can lead to lithium plating, a dangerous phenomenon that can lead to short circuits. This is why all Canbat LiFePO4 batteries have a built-in BMS that prevents cold weather charging. BMS is also responsible for protecting against other factors, including:
High temperature charging
overcharge
overdischarge
Internal short circuit