QOTD/CC Tech – What’s The Best Way To Store A Plug-In Hybrid Car?

Yes, I know that we do mostly old cars here, but I have built up a respect for the brain trust of CC readers, so maybe some of you can help me with a question I have been asked.

Someone I know owns a 2018 BMW 330e.  That person has to leave the country for a year and wonders what to do with the car.  The choices are to sell it and buy a new car upon return, or to store it so that a very satisfactory car is ready and waiting at the appointed time.

The question whether to sell or not is pretty basic, of course.  My read is that the car market and the economy is going to get weaker as time goes on, so selling later this spring might not be a bad deal if there are some good incentives on new cars next year.  But we all know how difficult it is to tune a crystal ball to eliminate all of the static and there is a lot to be said for keeping a car that has made you happy.  I should add that this decision is being made in Hawaii, where the economics of buying and selling cars is a little different than it is on the U.S. mainland.

The more interesting (and more technical) question is whether it is a good idea to store an electric car and if so, what’s the best way to do it?  The BMW 330 is a plug-in hybrid that mates a turbo 4 to a 7.6-kWh air-cooled lithium-ion battery.  We are all aware of how you deal with the gasoline part.  Sta-bil in the fuel tank, tape over or otherwise seal any holes like the exhaust pipe or air intakes, and maybe put the car on jack stands to keep weight off the tires.  A battery tender, or maybe a battery removal would about finish that job, to my way of thinking.  But the big hybrid battery pack?  What happens to a hybrid battery of this sort if it just sits for an extended period?  Is there such a thing as a battery tender for an electric/hybrid?  Or do you just keep it plugged in like those battery packs for lawn equipment we (OK, I) keep forgetting to unplug in the garage?

The simplest method might be to give the car to me to use for a year, because storing an aging Honda Fit would be so much simpler.  And I would be happy to spend a year at the owner’s home in Hawaii if that would make things less complicated.  Those items, however, are not on the menu board, so we will have to confine ourselves to more realistic possibilities.

So here is the question:  Is it a good idea to store a plug-in hybrid for an extended period of time?  And if so, what would be the best method for doing that?  I (and the car’s owners) will be eager to see the the wisdom that will follow in the comments.