This is also why claims of round trip energy efficiency for BEVs need a disclaimer. You need to put energy in to heat the battery, so under certain conditions,

This is also why claims of round trip energy efficiency for BEVs need a disclaimer. You need to put energy in to heat the battery, so under certain conditions, your roundtrip efficiency can hit 0%; i.e. all input energy going towards heating the battery, and none going towards charging the vehicle.