I’m considering buying an EV to replace my aging diesel. I live in a very cold country where temperatures regularly dip below -30C in the winter.
I understand that EVs lose range in cold temperatures and that they need heating to use and charge without damage.
My question is this: if I plan on not using my car for several weeks, can I leave it unplugged and/or tell it to stop managing the batteries’ temperature to save energy and not damage the batteries?
I’m okay with spending half a day preheating it when I plan on using it again regularly, but I don’t want it to draw current all the time for nothing when I’m away on long missions.
For some reason, I can’t seem to find out if it’s safe to keep a fully unpowered EV in the cold for a long time…
I know enough about Li-Ion to know that they don’t like overcharging or undercharging, and even how they charge, since I’m an electronics engineer. But only at room temperature 🙂
What I didn’t know is whether the cold alone damages them. You know, kind of like when living tissue gets damaged under the freezing point of water because ice crystals form and pierce the cells irreparably: I thought perhaps one of the chemicals in Li-Ion cells also migrated away from where they should be, or formed harmful solids or something that would damage the battery cell - without even pulling or pumping any current.
It sounds like it might be safe to leave the car in cold storage with only a trickle charge then.
Also, I spoke to a friend who has a plug-in hybrid (a rebadged Toyota RAV-4 I think): he says there’s a control that he can set to warm, cool, auto or off for the battery pack temperature control, and he recently left his car parked at the airport for several days on off with the temperatures below -13F. So I’m guessing it must be okay to do that. Also, apparently his hybrid gives up and simply refuses to run on batteries below 10F, so I’m guessing the battery pack warmer isn’t very powerful and it’s not too critical to let it go cold.