Can leaving the interior light on overnight flatten a battery?

Put it away about 4pm yesterday and just gone out to find it flat, refusing to crank. Clock has defaulted back to 00.00

I've put the charger on which indicates 11.5v but the block indicator is empty.

Other thing I've noticed is over the last year or so I've put the charger on overnight and found the starter is more eager a couple of starts before going lazy again.

Steve

Batterys probably past it's best and well down on capacity to when it was new. If/when we get a really cold night it'll probably be even less eager to turn it over!.

Ian

I keep the car in the garage at home, thing is just checked eurocarparts and they spec a 75ah whereas the one on it is 60ah. Its been there since I bought the car in Feb 2011...

Yes an interior light could flatten a battery overnight your battery maybe past its best plus if the spec is wrong that will not help plus these days there's lots of cheap inferior quatily batteries on the market .

Absolutely it can
I have the book and t shirt



Andi

Caught me out with boot lid not closed, little bulbs drain lots overnight.

Yep, faulty boot switch caught be out a few times till I found it.
- The give away was a patch above the rear quarter that was dry when the rest was wet!
- Still managed to not do anything about it and lend it to the GF for a week without telling her...


Daniel

[Edited on 15/12/2014 by dhutch]

There used to be problems with E30 BMWs, where the battery would flatten over night. The cure? Remove the boot light bulb, as the switch was faulty meaning it was on all the time. So yep, it can happen!

[Edited on 16/12/14 by blakep82]