Battery drainage on cold days.

[Exerqtor]

Well as the title states i have got some problems with my 2000 A8 draining these day's as the temperature creeps down towards -20C. I changed brushes and diodes on the generator + a new battery last year. But i'm starting to think that's it's something else draining now.

Is it anything particular on these cars that's known to break down and discharge the battery's?

[sloss]

Have a look Here (http://forum.a8parts.co.uk/showthread.php?t=5677&highlight=battery)

[graynada]

Just because the battery is only 1 year old do not discount that it is knackered. I would get the battery tested if I were you.

[The_Laird]

as the temperature creeps down towards -20C

I've never experienced -20C (closest I've ever come is -17), but I'm sure I'd feel a little 'drained' if it were that cold! :cool:

I'm sure the clever folk will be along shortly to tell you what effect temperature has on available current..... :D

[Exerqtor]

Well i ordered a new AGM battery today, so let's hope that helps.

Just thought that it might be a known component failure problem that could cause this sort of problem on the D2. Know that the BMW 5 series from 2000 have problems with a control unit not going to "sleep mode" and draining the battery over night just because of the minus lead on the battery. So just wanted to ask ;)

I haven't bothered measuring for any unwanted usage with the ignition on yet. But if the problems prolongs after changing battery something have to be wrong :P

[oldnick]

if you can spare the car for a few days try disconnecting the negative when you get home [ so the battery is charged , check the voltage in the morning , then test again each day to see how fast it drops

I've done mine like that and once it got to 12.7 it hasn't dropped at all , so is good


don't forget that the CCA quoted is at something like 20C ....and at -20C that is reduced by ....50% !