Solar Battery Maintainer through Batt B+ post

[Redraptor141]

Evening all,

I’m going on business in the summer for a month and the X5 will be parked up at work with no one to keep her ticking over.


Ideally I’d plug in a battery conditioner to the mains and leave that on but that’s not an option.

My father in law though has a solar panel with a voltage regulator on it for his Motorhome. And he said I can borrow it. Problem is the X5 has darkened windows on the rear so it needs to go on the dash, and the panel has shortish cables (it’s designed for a battery in the engine bay) so would I be able to hook it up to the B+ Post in the engine bay and find a suitable earth for the negative?

I know the alternator charges through this loop and the current for the starter flows through it. But my main concern is the negative terminal. Where do you think I should hook that up to? Just any Earth I can find under the hood?