The common RV battery for cold weather is a LiFePO4 battery. These can be used down to -20°C (-4°F), but you must not charge them below freezing, it will destroy the electrodes. The batteries integrate a heater which absorbs charging energy until the battery is safely warm enough to accept the charge, then charges normally.
In an EV this would be handled when charging by running a heater until it is a safe to accept charge. When driving, any time the battery becomes too cold you would divert regenerative braking energy into heating the batteries instead.
In an EV this would be handled when charging by running a heater until it is a safe to accept charge. When driving, any time the battery becomes too cold you would divert regenerative braking energy into heating the batteries instead.