My MGB battery defies all logic. I've drained it completely at least 5 times in the last 20 months - so much so that there is not enough juice to light the interior LED light. Jump start and it's back up to strength by the time I get to work.
It's usually the heated rear window - the car has had a badly wired new aftermarket fusebox fitted by a previous owner, and as a result most of the switches are permanent live rather than switched live. I have a 'routine' when I park up to check that all the switches are off, but if I'm in rush, or get distracted when I stop I forget and pay the price the next morning!
I'll get round to fixing it one day, and possibly need a new battery at some point, although it got through last winter with no problems and she lives outside 24/7.
