I'm confused...

 

I had a previous dsg issue which pointed at a failing battery as a possible problem. The 6 year old original battery was reading 12.2v on the car so I bought a new Varta e44 and after  charging it to top it up, fitted it on the car. After just a couple of days I checked the voltage on the car and it was down to 12.3v...parasitic drain I think? (Not something I have dealt with before), so disconnect negative battery lead put meter across and get 0.23amps...bad thinks I.

Then read about better way to check using millivolt drop across each fuse. Consult the Humble Mechanic youtube video and prepare car accordingly - wait 2 hours then proceed to check all fuses (in car and engine bay), could find nothing..check  voltage across battery terminals and I'm getting 12.6v......

 

So when I've checked the battery immediately after opening car and it is showing 12.3v is that because the car has just woken up?. 

 

The battery off the car reads 12.6v....

 

The old battery after 24hrs on charge and 24 hours later is reading 12.45v..

 

Should I just forget it and drive the car?

 

Words of advice welcome.

 

Fats

1 hour ago, fatscoleymo said:

The 6 year old original battery

 

Was the original battery an AGM battery?

Nope...

Parasitic drain on my Superb 3 is about 12mA very occasionally increasing to as much as 50mA for 10 to 30 seconds while some controller is doing something.

 

When you lock the car it takes 3 or more minutes to shut down all the systems during which time the consumption is in the hundreds of millamps range. You have to measure with all doors closed.

 

I measured mine indirectly, being the charge current after 2 days to maintain 13.40 volts so I didn't disconnect the battery. If you disconnect the battery I imagine it would take several minutes or more before the car systems went to sleep after reconnecting.

Edited 6 October, 20187 yr by xman

3 minutes ago, xman said:

If you disconnect the battery I imagine it would take several minutes or more before the car systems went to sleep

 

I guess in the mean time those systems would hold their breath until they pass out ...

15 minutes ago, vborovic said:

 

I guess in the mean time those systems would hold their breath until they pass out ...

 

Corrected with the missing "after being reconnected"

Went back to the car, unlocked it, opened the bonnet and immediately checked the battery - 12.37v.

Left it 15 mins and it reads 12.55v.

So I guess it's just as bits go back to sleep after opening/ closing the voltage increases.

Happier now, I'll just drive it and occasionally monitor the battery.

Thanks for input.

Fats