The whole idea of having this carputer was to always being able to locate my car. For this – obviously – the device had to be always on.
BMW has a really sensitive power management. It measures the currency and already was being annoying from the start. Everytime I entered the car I got an error message that the battery got drained more than usual. Of course I knew why but I just couldn’t do anything about the message.
That, however, is not the actual issue. Not only did the car think its battery would be drained more than usual, the Raspberry Pi really does need quite some power. Leaving it on permanently works for two, maybe three days when I’m moving the car regularly. Without driving the battery won’t survive the weekend. I then started to just charge it every few days. I must say, I’ve gotten used to it but really it’s pretty annoying.
That’s why I built in a switch. It seemed like a good idea but this also turned out to be not the most ideal solution. When I turn the switch on the Raspberry Pi turns on as well. When I know I won’t move the car I’ll just switch it off.