Battery problems - The Unofficial BMW M5 Messageboard (m5board.com)

shamus_mcd · 7th January 2009, 19:48

Looking for a bit of info.
The other day my car wouldn't start as the battery was flat (No dash lights or anything)
I charged the battery for a day'ish and basically car would just click when key turned.

I Bump started it and took it for a 50 mile drive stops and starts no problem so I left it over night on trickle charge.

The car has sat for 3 days and battery flat as a pancake again

What I've found is if I disconnect the battery completly the battery is showing fully charged but when connected the battery is showing 3 of the 4 light need to go out for a charge.

I think this is a pumped battery

Would I be correct in this?
Anyway to check?
The car is charging now but seem to only get as far as 2 light out and 2 to go.

I've checked and no lights on in boot or car radio off sat nav off as screen goes blank and i'm a bit stumped.

I think the car has had a battery before in it's history before me.

If I do need a battery what kind etc etc
I think it's a 100ma 720Ah is whats in it just now.

Car has been fine up until the other day.
Left it in Sept for week and a half and burst into life on my return.

HELP

manminder · 7th January 2009, 19:54

That is a classic sign of a battery not holding its charge. You need to replace it.

TMcNasty · 7th January 2009, 21:06

If a battery cannot be charged it is defective. End of discussion. Being that you're in Scotland I'm not sure how you can get another one besides a dealership.

Redneck M5 · 7th January 2009, 21:19

If you have a voltmeter you can read the state of charge for the battery. 12.6V is a fully charged battery. If you can't charge to 12.6v, replace it.

When running the alternator should produce well above 13 volts.

You may have a bad battery. You may have additional issues, but there needs to be a good battery to find out.

jonsmiff · 7th January 2009, 21:37

youre battery sounds like its gubbed, and also it should be an 800 or 850 ah battery,you need to check youre charging system just to make sure its up to scratch,i changed my battery a couple of weeks ago to one of these http://www.performancebatteries.co.u...s#battery_info 70 quid delivered next day for a 100 cca 900 ah with a 3 year warranty,or halfords do one that is slightly less powerful for 100 quid(with the halfords trade card this comes down to 75.00)if you are anywhere near the west end of glasgow i am quite happy to test it for you.

jclyman · 7th January 2009, 22:14

A disconnected battery will give FALSE voltage readings. It must be checked using the appropriate load.

zanta · 7th January 2009, 22:15

i've had similar problems today..
Actually my car has been in cold garage since beginning of November.
So I forgot to put battery to charging when i put car in garage....
It an out of charge... and I wondered why it's not charging...
So I thought I'll take the battery to battery shop for test...
i took it from the trunk... shait... It had frozen an totally broken...
lasted totally 8 years

it was the original one. durable battery.
last winter no problems from -35c starts
battery even had sticker where was text tellin it should be changed 1-2005

take it out from the trunk, see if it's ok.
just buy new one, i looked that replacement batteries are here from 100€->

maxrpm · 7th January 2009, 22:39

Quote:

Originally Posted by TMcNasty

If a battery cannot be charged it is defective. End of discussion. Being that you're in Scotland I'm not sure how you can get another one besides a dealership.

Yeah so take your horse and kart and go get one lol

shamus_mcd · 7th January 2009, 22:56

Quote:

Originally Posted by jonsmiff

youre battery sounds like its gubbed, and also it should be an 800 or 850 ah battery,you need to check youre charging system just to make sure its up to scratch,i changed my battery a couple of weeks ago to one of these Car Batteries, Cheap Car Batteries, Replacement Car Batteries, Next Day Delivery from Perfomancebatteries.co.uk 70 quid delivered next day for a 100 cca 900 ah with a 3 year warranty,or halfords do one that is slightly less powerful for 100 quid(with the halfords trade card this comes down to 75.00)if you are anywhere near the west end of glasgow i am quite happy to test it for you.

Is this the one?
Where are you?
I stay in Law near Carluke but i'm off to Thurso tomorrow back Friday night.