 People don't realize that on these European cars, there's a bunch of them that are like that. When we have one removed at our shop, we hook battery backup to it, which is very minor, and move the cables off before we swap the battery. Then we put the battery back in, put the cables on, and remove our power supply. So we've always got a little bit of that computer battery backup to the unit. How many volts is that when you do that? Is that a full 12-volt, like a little small charge? You just need a tiny 12-volt, little tiny battery.