540i e39 battery dead and will not charge. Need Help please! &#33

[dkonsta1 109]

Hi guys. My 540i was left in the garage for a couple of weeks probably with the ignition on in position 1. It died so I could not start it. Even jump start from the other car did not help.

Called AA. They used the big cables in the engine hood to jump start into, not enough so they plugged the portable jump starter at the battery as well. With both aids on it started straight away. I drove the car for 30 minutes. Left it at the garage again for 5 days.

Today dead again. I got a supercheap auto Calibre digital battery charger. Disconnected the battery plugged the charger on but it does not bring any lights on (boost or float) just powers up. It doesn't seem to charge.

Any ideas? Cheers

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[aja540i 1903]

Those new automatic chargers wont do anything unless they can detect a battery, it sounds like yours is too far gone to detect. If you have an old style charger it will just throw 12 volts at no matter what, but it sounds like it might be time for a new battery.

[dkonsta1 109]

Thanks guys. The battery is AA brand and only 18 months old. I will get AA to start me and check alternator.

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[aja540i 1903]

I dont trust the AA guys totally, one of them tested my system when they had to jump start my 540, told me the alternator wasnt charging, i put a new battery in it and 4 years later it is still fine! Any competent auto sparky should be able to check it for you and tell you the problem.

[dkonsta1 109]

Looks like we have a happy end. The battery was down to 6volt. Alternator is charging fine.

I drove the car for an hour and now hooked up the charger. It recognized the battery and it is charging.

Fingers crossed....

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[dkonsta1 109]

Thanks all for your feedback

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[KwS 2378]

Completely draining a battery is not good for it, its probably stuffed now, although half an hour driving wouldnt be long enough to charge any battery that was dead flat to a point where it could be left sitting for 5 days.

Take it out of the car and try borrow a decent high amp charger and see if it can revive it.