Determining what is draining my battery

Hey All

Wondering if anyone can help - i took the dash out a few weeks back and fixed a load of bulbs which were either missing or blown and replaced the steering wheel. I also tidied up some wiring, tied bits up, re-crimped areas which were messy.

Then, my wife moved the golf and left the lights on which drained the battery.

Since then i have jump started it twice, once driving it for a good 20 minutes and the battery gradually drains. I can't yet tell if the battery is playing up or me taking the dash out…

The battery is less than a year old - it is possible it would be knackered so soon? What would be my next step forward?

Thanks

Alex

there is always the possibility that the battery is duff.

what you need to do is get a multimeter and measure the current draw from the battery when the car is turned off….there shouldn't be any unless you've got an alarm fitted.

To do this, connect the meter in series off the battery and switch to AMPS on the meter…..this will show the current draw.

……..then take the fuses out one by one and see when the reading drops, thats the circuit with leak.

Its unclear from your post if its not charging when running? Should be showing 14-15v with engine running and @13v for a fully charged battery.

Once a battery has been total discharged it can only ever retain @ 70-80% of its capacity, so I'm lead to believe.

A number of years ago I went through about 3 el-cheapo economy batterys, they lasted about a year until the first winter than I went and got another under warrenty. After being sick of my car not starting and teh hassle of swapping I began to buy Bosch batterys, usually 1 or 2 sizes up from what was required, i.e. if the standard was a 45 amp one I'd get a 54 or 60 amp one. Only cost a few quid more and 1/4 or 1/3 the capacity again.

i've had a couple of the Bosch Silver batteries and they've been spot on

spaceace said

there is always the possibility that the battery is duff.

what you need to do is get a multimeter and measure the current draw from the battery when the car is turned off….there shouldn't be any unless you've got an alarm fitted.

To do this, connect the meter in series off the battery and switch to AMPS on the meter…..this will show the current draw.

Okay, i have a big multimetre - couple of questions….I have a cobra immobiliser which has a single solid LED and is deactivated by touching the thing with my fob. I then have 30 seconds to start the car, else it's immobilised again. What kind of draw would i expect that to be eeking out?

When you say "in series" - do you mean remove one side of the battery connectors and put the multimetre inbetween the cable and the battery contact?

correct about the in series…just make sure your meter is on AMPS

Alarm current draw, not sure about this although I'd be surprised if it was over 500mA (half an amp)

What you could do is measure the current draw then start unplugging the fuses to find the culprit (making sure you mad a note of which fuse went where)