Ongoing battery drain issue

[Worcester_spoon]

Posted a couple of times about this, but need to sanity check I'm not going mad.

So, left alone, battery is going flat inside 3 days.

Have checked amps on shut down looking for a parasitic drain - shuts down normally, draws just 0.02 amps when fully shut down so appears not to be a problem there.

Followed some advice from here looking at the volts from the alternator when running, sits at 14v, drops briefly to 12v when loading up (lights, full beam, fogs turned on) and then quickly comes back up to 14v so clearly not an alternator issue.

Process of elimination therefore means can only be a defunct battery. It's a Bosch S5, bought a year ago, so it's strange it would be faulty, but I cannot think of anything else that could be causing it to go flat inside 3 days, so it must not be able told a charge.

Any other ideas welcomed, or please tell me I'm not going mad and this is the most likely cause.

Car is expensive driveway porn at the moment as it's unusable

Stu

 

[markplant]

Is there any non standard electrics on the car. A gaptech or intravee or similar. IPod on constant charge in glove box, I am just guessing at this point

 

[markplant]

Is there anyone could lone you a known to be good battery. Fit it leave it to stand for 4 days or so . if its drained the lone battery then its the car not the battery at fault

 

[ocrx8]

This happened to me - I found the below post, which mentioned about the Bluetooth module continually searching form connection, hence the battery draining. I removed the specific Bluetooth fuse, put it back in and have had no problems since (18 months ago). Worth a go, assuming you have Bluetooth!!

http://www.bimmerforums.com/forum/showthread.php?1896507-Draining-Battery-2006-Z4-m-roadster

 

[Worcester_spoon]

Thanks guys. Gaptech is fitted, but the draw is only 0.02 amps when shut down so it's not something in the car (I don't think). Going to borrow the battery out of my mates Z4 next week to try that idea as I honestly can't think it's anything other than a dodgy battery.

Fingers crossed...

 

[Scooba_Steve]

Battery sounds likely to not be holding charge. Once one has been run down it wont be back up to full again. I got a Varta E44 online for £68 and I've been happy with it. Have you checked your battery once charged?

 

[markplant]

In your signature states a parrot is there a any draw on that when left stood . as ocrx8 mentioned is it constantly searching for a connection. If you can find the circuit its tapped into as may not have been one that you checked before. Still guessing

 

[Worcester_spoon]

So, new battery in place for almost a week. 5 days without being started. Go out there today full of trepidation, turn the key and bang, SHE STARTS!! Hopefully (fingers crossed, lucky rabbits foot rubbed and 4 leaf clover put on display) that's the end of my battery issues - just a duff battery.

Next up, Bilstein shocks, new bushes all round, a trip to monkey towers for a custom exhaust and a full on detailing... Back to the fun

 

[ronk]

Don't you just love a result like this - I assume you haven't lost the warranty papers!

 

[Worcester_spoon]

Nope, so free replacement

 

[ronk]

An old pal of mine bought a battery many many years ago - the shop offered lifetime warranty to the original owner ----- he kept the car for twenty years or more. He had a few new battery replacements. The shop was well sick of him !

 

[Newbers]

One other less obvious thing to watch out for: All of the live (red) cables from battery, alternator and I think starter are joined a small junction box on the bulkhead (back of the engine bay). If this becomes loose the full current from the alternator doesn't make it to the battery. You'll get the voltage readings you'd expect but not the amps (so battery doesn't charge). You have all the symptoms of knackered battery - or alternator but meanwhile the junction box is glowing red. It's an £11 part but has a big impact if it works loose.