Battery drain . 20 mili amp at the meter .

[robrado974 1]

Robbie r32 and i fitted a kenwood unit around two weeks ago . On the saturday after fitting on a friday i had the door open for an hour and a half , while a drivers side central locking fault was sorted . With that fixed i went to start the car and the battery was flat . We used a jump pack and it started and i drove home [around 20 miles ]. I went to start the car the next day and it was flat again . So i charged the battery and used the car over the weekend with no problems , however on checking it tonight there is a loss of cranking power . I presume that the alternator is charging as i have no problems unless the car is sat for a couple of days . I had to purchase new plugs for the head unit and follow the wires to conect them to the new plug . I cant see any other reason why the battery is going flat other than the head unit is somehow draining it, as it was fine before fitting . But if i have followed the wires correctly why is it draining it ?. Something to do with the ignition live perhaps ?. I also noticed the boot light was a bit dodgy so i disconnected this on saturday . Any help is much appreciated as always .

Rob

Edited April 29, 2014 by robrado974

[davidwort 0]

How old is the battery and what sort of use does it get?

if you have a multimeter that can measure current inline then check and see what current drain there is with the ignition off, don't operate the ignition or locking etc though as it will pop the internal fuse in the multimeter.

[robrado974 1]

The battery is around 3-4 years old David . I usually drive the car at weekends and during the summer time evenings . I do have a multimeter that i bought a few months ago but have not learnt to use it yet !. So im not sure what setting to have it on and how to measure the inline current ?

Regards Rob

[davidwort 0]

I've been through a few heavy duty batteries including Bosch silvers in that sort of timescale, they are much better being worked hard every day.

if your multimeter has more than two connections for the test leads then it should do low current amps tests, you simply put the two leads between the battery connection and the battery lead instead of across the two terminals, the manual with the multimeter will show you which lead connections on the meter to use for amps.

[robrado974 1]

Thanks David , i will have to work out how to use it . When i recieved the meter it came with a cd instead of a manual ,the cd had a big crack in it so i cant use it . I will google it and hopefully find out what is going on . It is a bosch battery i am using on the car .

Rob

[carrots 1]

i had a problem with my alpine head unit draining the battery after a few days,i took a live off the ignition and it sorted the problem

[robrado974 1]

Thanks for the reply Carrots , this was one of my thoughts too .

Rob

[robrado974 1]

Ok , I have put the multimeter on and I'm getting a reading of 20 mili Amps , 00.2 .Can someone confirm if this is correct or wrong please

Many thanks

Rob

Edited April 29, 2014 by robrado974

[davidwort 0]

20 or 200?

that's a bit high I think, I'd expect around 0.02 on the meter, I'd start pulling fuses :)

[davidwort 0]

taken from tdiclub.com (for more modern VW's I think)

VW has a bulliten regarding "static current draw" or as I've heard it "parasitic

drain". It says 40 milli amp is acceptable draw on all cars except phaeton,

which they say 50 milli amp is allowable

[Roger Chatfield 0]

Dave, thats a typo on Robs part, I spoke to him earlier and it was 0.02 amps (20 milliamps).

 

Rog.

[davidwort 0]

OK, looks like a duff battery then, if you take it to a garage they should have a deep discharge tester to check if it can deliver cranking current.

[robrado974 1]

Many thanks David and Rog . I will get it checked tommorow .

Rob

[robrado974 1]

Thankyou for your help everyone . I fitted a new battery today . Super fast cranking !.

Rob