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monitoring current draw?

Posted: Tue May 27, 2008 7:28 pm
by fil
s4 b5, got a flat battery, jump started the car, but seems to be rapidly dying.

Any way of using vagcom to see what the current draw is when the cars off?

Just to confirm a nackered battery, before i get a new one and knacker that too!

cheers

RE: monitoring current draw?

Posted: Tue May 27, 2008 8:34 pm
by yorkie
Been here mate, disconnect the earth lead from the battery (when it has some charge in it) and put an ammeter between the lead and the negative post. The current draw with ignition off should be no more than about .3 amps.

If that is about what it reads will almost certainly be the battery assuming the charging circuit is ok i.e good voltmeter reading and no warning lights.

I was assured by the local tyre place that my battery was fine when they stuck one of those testers across it and spent the next month tearing what little hair I have out trying to find the cause.

Mate came round with proper workshop battery tester and battery was knackered.

RE: monitoring current draw?

Posted: Tue May 27, 2008 11:14 pm
by fil
cheers for that, but have no ammeter, and no way of geting one as cars dead, and when see gets home, i leave for work! ( nights )

hence was hoping i could check it with vag com, before i get the bus to halfords, buy a battery and bus back home, just to find serious issues, as there was a lot of rain monday!

RE: monitoring current draw?

Posted: Wed May 28, 2008 9:32 am
by S4
There is a nasty way to give it a test with no tools... we used to do it all the time ( but it will only work if it has caps you can remove and see the cells) it needs 2 people and a torch! 1 gear foot hard on brake, and crank! if you have a dud cell it will go cloudy, and the others will stay fine.

Darren

RE: monitoring current draw?

Posted: Wed May 28, 2008 1:51 pm
by fil
cherrs , no go just myself,

just got up in the hope it had enough charge to start, to ghet a new battery, nope 8.2 volts, bugger

RE: monitoring current draw?

Posted: Wed May 28, 2008 6:22 pm
by yorkie
Get the Mrs to buy you one, doesn't need to be super expensive, Halfords do a Gunson one for 18 quid.

My money would be on the battery though.

RE: monitoring current draw?

Posted: Thu May 29, 2008 2:12 pm
by fil
its all down to time, tho which i havent got,

she got home just b4 7 yesterday, so popped to halfords, and got a battery, then went to work, so just up now to go and fit it, hope it is the battery, 93 quid!