Battery on the M5 deains down really fast - a right PITA.

I've had it tested and it's not something obvious


Anybody tried something like this?

Battery protector

 

I bought one for my expedition Land Cruiser because I had all sorts of stuff running off the main batteries, not least of which a fridge, but I never got roung to installing it. I got away with it because the batteries were huge and I was careful to turn things off if I wasn't driving the car for a couple of days anyway.

I think you'd only be skirting the problem rather than fixing it. I'd start by trying to determine what's drawing the current - probably the alarm or satnav - and see if that can be improved.

What's your definition of really fast, anyway?

 

Runs down in about 4 days.

Problem is that it's been to BMW for diagnostics and they can't find anything. I reckon an auto-electrician would need a week with the car to find the fault.

Want to seel your one?

 

Already did, sorry.