D3 battery (warm wire)

[mannyo]

When researching the low battery on my newly acquired 2004 D3, we noticed that the thick wire between the wing/battery on the terminal closest to the rear of the car was warm (not hot, just not cold).

The car had been started a couple of times whilst we checked the voltage with a multimeter. Which wire is this, is this the feed to the starter motor? or perhaps one of the alternator wires?

The same terminal also has a very thin wire and another thick wire running on the boot side of the battery.

[M-A8]

..it's always like that with new cars, people just worry to much, just enjoy it mate, don't worry about it, this isn't a problem.

Battery level - give it a good run, I mean good run not 10-15min run. Go for a nice long ride and enjoy every minute of it.
After run, every morning for next few days just check the battery level in MMI before starting an engine.

If level is at 100% for the next 7 checks lets say then it's all good, just needs probably a good run as it's probably undercharged.

IF not, and level is keep dropping then just get a new battery, Bosch Silver S5 £130quid, not bad and will last for years, but I'm quiet sure its just need good charging.

[Dezzy]

It's not a bad run from Southampton to Blandford. If it needs a longer run i'm happy to take it away for you for the wk end Mannyo obviously i'll leave you an 8 as a courtesy car.

[mannyo]

Well, the battery charging situation was not improving and the battery meter was remaining stubbornly at around the 10% mark. Today I popped in to a local independent who used another tester to run a more comprehensive set up tests on the battery, the verdict is that its foobared.

One replacement Varta battery will be fitted later this afternoon which should hopefully sort out all the low voltage ECU faults and other anomalies such as the keyless go disabling itself due to battery management fault.

I must remember to recode the battery ECU when I get home.

[mannyo]

Battery has been replaced with a Varta, and all is good. Everything in the car is now working properly, keyless entry/start which I could not use before now works.

One problem though, the bolt that holds the battery in place was hanging in thin air. The nut on the other side was missing, when they came to undo it, the bolt was just spinning. Can you get to the bottom of the bolt from the outside, then I'll put a washer and nut on from underneath.

Oh, and I cant recode the battery ECU. My ahmm VCDS cable cannot connect to the controller, I need to get around to buying a genuine one as this one seems flakey with the CAN protocol.

[Somerandomguy]

You can get to the back of the retaining bolt, but only when the battery is removed!

I went through a few options when the thread stripped in mine, I spent about an hour with the dremmel cutting the head off the bolt.

Having freed the battery, the captive nut is pretty large, so i tried putting a bolt up through the hole, with a slim nut holding it in place, but couldn't get the battery over the top without a lot of lifting and shoving.

In the end, i bought an aluminium 10mm captive nut and fitted it into the hole. Its fairly easy to make a compression tool by tightening a bolt with a washer into the compression nut.

I went with the 10mm nut as this fitted the existing hole (tightly), but did mean a larger bolt is required

I think I have a spare or two, so can post it to you if you want to give it a go.

[mannyo]

Originally Posted by Somerandomguy

In the end, i bought an aluminium 10mm captive nut and fitted it into the hole. Its fairly easy to make a compression tool by tightening a bolt with a washer into the compression nut.

I went with the 10mm nut as this fitted the existing hole (tightly), but did mean a larger bolt is required

I think I have a spare or two, so can post it to you if you want to give it a go.

I am happy to give this a go, I can PM my address over.

[limoncello]

Mannyo

you may find that it wasnt the battery at fault, in which case the 10% will reoccur in the display in around 2 to 3 weeks which is how long it takes to drain the battery or think it does, if you have trouble starting it is draining the battery, and it may have zoned the battery so you did need a new one anyway, if things just get turned of and you have no problem starting

if it does reoccur see here for the probable explanation and fix, if its killing your battery get it done asap before the new one goes too

http://www.audi-resource.com/mmifalsewarn.php

[mannyo]

Originally Posted by limoncello

Mannyo

you may find that it wasnt the battery at fault, in which case the 10% will reoccur in the display in around 2 to 3 weeks which is how long it takes to drain the battery or think it does, if you have trouble starting it is draining the battery, and it may have zoned the battery so you did need a new one anyway, if things just get turned of and you have no problem starting

if it does reoccur see here for the probable explanation and fix, if its killing your battery get it done asap before the new one goes too

http://www.audi-resource.com/mmifalsewarn.php

Whats really annoying is my VCDS cable will not connect to the battery ECU, I tried for ages last night. its a third party cable and always been a bit flaky with CAN. I therefore have no idea what version the software is. The car is running better than ever, and seems to start much better than before however.

[limoncello]

yes mine did for 2 weeks before it came back, when you do a scan i guess it also doesnt scan the energy manager