Cold weather lithium heating pad wiring

Lithium batteries with internal heating pads need the heater to have power available even when the battery itself is too cold to charge — which means the heater circuit typically needs to be wired to a power source that's active independent of the battery's own charge state, or the battery can get stuck in a cold state it can't heat itself out of. Check your specific battery's wiring diagram for how the heater circuit is supposed to be powered. What's the battery brand?