Dead Battery again!!!

porker914 · Post by **porker914** » Sat Dec 02, 2006 10:53 pm

Having used my 14 for the first time in a year 2 weekends ago I went to start her again today and the battery was virtually dead and could not start the engine. The battery is not very old maybe a year or so old, but what can cause a fully charged battery to die in just 2 weeks ? I have no clock etc that may draw current when the ignition is off?

2 weekends ago i used the car all weekend without any problems. Any ideas.

David

Helen · Post by **Helen** » Sun Dec 03, 2006 10:44 am

no idea but i have had the same thing happen to me..

it's very annoying

Nick Moss · Post by **Nick Moss** » Sun Dec 03, 2006 11:05 am

Do you have an immobiliser? They are the worst form of current drain. Certain radios also drain the battery if they are not wired through the ignition switch. Take out the fuses one by one and using a tester see if you have current across the terminals. If all else fails just disconnect the battery between uses.

912uk · Post by **912uk** » Sun Dec 03, 2006 11:45 am

like Nick says it's going to be a drain some where Rather than the battery ( unless it is an old battery )

I had this on one of my cars once turned out to be a interior light was still on... If long term storage I take the battery out and put it on permanent float charge..good as gold now.

Helen · Post by **Helen** » Sun Dec 03, 2006 11:46 am

cold weather always seem to play a part too.. don't think i have ever had trouble with a battery in the summer

Barry · Post by **Barry** » Sun Dec 03, 2006 1:02 pm

Was the battery allowed to run flat the last time? From what I gather, you may get away with running a normal lead acid battery down to 50% a few times, but much flatter than that and you get a build up of 'stuff' (shulphides?) on the plates that then reduces the battery's performance.

If this is the case, the classic symtoms would be reluctance to take a large charge, even if flat, voltage comes up quite quickly but fails to peak very high and then virtually no capacity when charge, or sudden loss of charge.

The way I would look at this would be (and what I do on my cars):

1) Turn off everything on the car. Disconnect battery at the negative and set a volt-meter to amps. Put the meter from the negative terminal to the negative lead (i.e. hook the battery back up, but through the meter). If there is any reading, track down the source of loss. Even a tiny amount will tot up, say .1 amp, is the same is 2.4 amps per day, 72 amps per month etc etc.

2) Use a battery minder, main brand name being Optimiser (£30-40), although almost everyone has their own brands now (Halfords do one for about £12). Most of them come with a lead that can be hard-wired into the car's loom, so that you plug the charger in without using crocodile clips.

3) Keep the battery charged all of the time, if you ever run one flat never trust again: they're never the same.

4) Keep the terminals clean and vasalined.

5) Keep earth leads perfect.

I'm sure you are on top of all of the above, but there may be something there of use to someone

.

Hope you're well, BTW

Barry · Post by **Barry** » Sun Dec 03, 2006 1:05 pm

Forgot to say, I always run the negative lead slightly loose, and just unhook it when the car's parked up: as much as an anti-fire risk as anything else, but saves worrying about flat batteries.

Even so, I charge my batteries monthly. It works though, I've never had to replace a battery that I've owned from new (literally).