What can cause a voltage drain...

[Penfold101]

...when the ignition is turned off...?

Basically if I leave my car for a couple of days without starting, the battery dies. And given that mine is a 450 amp model that's a lot of electrons to go missing...

Local VX garage have had a look and said that it's not the battery, there is actually a drain somewhere that's causing it. I had hoped it was jsut the battery giving out which would have been simpler...

The only things I've added in are the Travel Assistant and the reversing camera, the power supply to both I've isolated by pulling fuse out and it still happened.

The garage want the car for a few days to track it down, but obviously I really don't want to go down this route.

Is there an easy way of locating this? Would a multimeter and lots of voltage checks across every plug I can find with the ignition off be the best way forward...?

As you can understand, it's a nightmare having to jump start this beast, and it almost melts my jump leads in the process...

[Deztroyer]

Hi Martin

have you metered across the battery when the car has "powered down" into sleep mode???

trigger the bonnet switch so it thinks its shut - lock the car and measure across the battery - the voltage should drop after a minute or two as the cars ecu powers down. and you should see a significant drop in the reading.. if not then something electrical is still "live and powered up ...

it would be a case of disconnecting the main sources of power in turn to see if the voltage remains constant or indeed improves ....time consuming but a man of your calibre would find this cheaper than a trip to the dealers

i suspect something to do with the radio ?? - shall we have a sweepstake

regards

Dez

[Penfold101]

Hi Martin

have you metered across the battery when the car has "powered down" into sleep mode???

trigger the bonnet switch so it thinks its shut - lock the car and measure across the battery - the voltage should drop after a minute or two as the cars ecu powers down. and you should see a significant drop in the reading.. if not then something electrical is still "live and powered up ...

it would be a case of disconnecting the main sources of power in turn to see if the voltage remains constant or indeed improves ....time consuming but a man of your calibre would find this cheaper than a trip to the dealers

I think I shall do this when I'm next at home and have got a source to jump it from, and my dad who knows a bit more about electomagicianry than I do, but it sounds logical enough...

I also don't own a multimeter as I'm more of a spanners person, and if I need to know a voltage I can jsut short it out and see how bright the sparks are...

i suspect something to do with the radio ?? - shall we have a sweepstake

Want to add a poll for me...?

[plasma]

Also bear in mind the life expectancy of the average vauxhall battery.. Mine would fail to start if left for 2 days or more.... A dead/dying battery can also give the appearance of a voltage drain.. New battery (85amp lol) and car is back to normal Can be left for 2-3 weeks without a problem

[Penfold101]

Also bear in mind the life expectancy of the average vauxhall battery.. Mine would fail to start if left for 2 days or more.... A dead/dying battery can also give the appearance of a voltage drain.. New battery (85amp lol) and car is back to normal Can be left for 2-3 weeks without a problem

I may jsut try that and see if it still comes back or not - it's just that my battery is a bit more manly than yours mate ...

As long as I start it every day and take it for a quick spin I'll be fine, it's jsut if I go away for a few days with work that I'll be screwed...

I could try simply disconnecting the positive and see what happens...

Best I get a portable starting thing like Matt and Gemz have...

[plasma]

erm, think you've got your current rating wrong there pinfold you probably talking about cranking amps.. Have a look as see what it REALLY is the 1.9CDTi's have a 70amp battery, so yours should be similar

[Penfold101]

erm, think you've got your current rating wrong there pinfold you probably talking about cranking amps.. Have a look as see what it REALLY is the 1.9CDTi's have a 70amp battery, so yours should be similar

more than likely - I jsut saw 450 amps written on the top of it and it's a LOT bigger than my dad's battery on his 1.8 Volvo S40. I also know for a fact that I can't start my car from his battery alone....

[plasma]

when i fitted the 85amp battery i had to remove the little rubber bung thingy nearer the engine bay to get it to fit, battery takes up the WHOLE of the battery compartment now lol, no room for tucking little gadgets in there anymore...

[Big Sig]

This is the battery you should have

Startup Power: 640 Amps
AH value: 70 Amps
Reserve Capacity: 130A
Bench Charge: 7.0 Amps
Weight: 16.75 Kg

If you say yours was a 450a cold cranking then its a bit under size really compared to what was in my old 3.0v6 derv.

[sshooie]

more than likely - I jsut saw 450 amps written on the top of it and it's a LOT bigger than my dad's battery on his 1.8 Volvo S40. I also know for a fact that I can't start my car from his battery alone....

Thats a small(ish) engine and requires much less cranking amperage than a diesel. The engine compression and drag on start up will be much greater on your diesel.

As above you could, if you have the correct meter see what the current drain is ignition off (make sure you have the radio code) then start by eliminating items like the radio etc.