Most of us are probably aware that Lithium batteries should be treated with great care to keep them safe. But one thing I wasn't fully aware of is the damage that can be done and the resulting safety risks associated with trying to charge a very cold lithium battery.
When you charge a very cold lithium battery some of the metallic lithium in the battery gets plated onto the anode of the battery. You can't normally tell or see that this is happening. This will very slightly reduce the capacity of the battery but more importantly it greatly increases the risk of an explosion or fire. No matter how well the battery is made, if sufficient lithium ends up on the anode an impact shock or any high temperature usage can cause the lithium to ignite causing a battery fire. The batteries management and protection circuits cannot protect against this type of failure, although some manufactures do include circuits that will prevent a cold battery from accepting a charge, many do not.
You must never try to recharge cold lithium batteries, they should always be allowed to warm up to room temperature before charging. Repeated charging at cold temperatures is dangerous and must be avoided.
Alister Chapman
Cinematographer/Producer/Trainer
