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I’m chasing a flat battery issues on the gf’s golf and wondered if anyone could give me a second reading for the values I’ve measured.
basically the problem is the battery keeps going flat. It’s a new battery with a recently replaced engine and will go flat after about a week or so.
To try and see if it’s the alternator I’ve taken three readings from hers and mine to see if there was any difference, but actually the batt also goes flat on mine after a few weeks too so I don’t know if the comparison will help. I always presumed mine goes flat cos it sits there unused most of the time.
So first reading was voltage on battery connected as it’s parked, second was battery disconnected to try and establish if there was a quiet ongoing load and third reading was whilst running. Increasing revs didn’t seem to increase charging voltage in any case.
Hers:
batt connected: 12.01v
batt disconnected: 12.02v (probably the flashing led accounts for the difference, so assuming no quiet load)
running: 13.72vMine:
batt connected: 12.08v
batt disconnected: 12.09v (also got a small led)
running: 13.8vReadings from both seem plausible – can anyone either take similar readings to compare or let me know if they seem wrong?
We mostly do short local trips so there really isn’t much charging opportunity so it’s possible that this is just how it is but something doesn’t quite seem right.
thanks in advance…
ok here we are with the figures
batt connected: 13.3v
batt disconnected: 13.35v
running: 13.9vMind you I do have a small solar panel (about 10 X 3 inches) permanently connected to the battery & this keeps the battery charged up.
btw, I did disconnect it before I read out the voltages! [
]Similar to this one http://www.ebay.co.uk/itm/12v-Solar-Panel-Battery-Trickle-Charger-caravan-car-/260476312443?
as for not using your car very much, according to the APK (MOT) certificates my Syncro did just over 4000 kilometers in the last year (about 2600 miles)
don’t get stuck on voltage readings
problem most likely is that current is drawn even when the car is shut of
so get a multimeter or an analog ammeter take the use the leads to “jump” the battery terminal (taking of the terminal, and use the meter between the terminal on the battery and the shoe
then start taking out fues, you will see the current drop when you find the right fuse, then trace wires from there
it should only be a few mA of current being drawn when not running/key off
if you got like 1.5A of current drawn when of. you got a problem. thats only 43hours of battery life on a fully charged battery
good luck
cheers housey – I’ll look into that. I wasn’t trying to get hung up on voltages but at the same time wanted to check things were within normal parameters before digging elsewhere or replaced the alternator.
I suspect there is an old alarm in her golf and that might still be draining some power. I removed the engine bay wiring for it when i sorted the subframe mount recently but haven’t looked inside yet to remove the rest.
Chris thanks for the readings, the little solar panel is a great idea – that could solve the problem on both cars while I poke around for whatever’s draining the battery – thanks
I have had faulty boot interior light push switches be faulty on several of my golfs, might be worth checking?
ah yes – damn sorry, completely forgot to update! Fixed it with bells on
I didn’t even need to go as far as measuring the current drain and removing fuses because I just thought I’d have a poke around and see if I could see anything. I peeked into the boot by folding the seats forward and tadaa – light was on. The switch had got knocked through the plastic so was always on.
We also installed solar chargers in both cars and they’re great! I’m thinking I’ve got space for a couple more on my parcel shelf and it might be enough to charge a separate battery (perhaps a small SLA) which would be used to power an amp or a better stereo of some kind. I never bothered fitting one because the last one I had kept leaving me with a flat battery but given how much time the car spends standing it might be a neat solution.
So thanks very much everyone that was another mystery rapidly solved
good to hear
its usually only small idiotic things which you would not even suspect would have anything to do with it that failes 
quote:
Originally posted by ld50ah yes – damn sorry, completely forgot to update! Fixed it with bells on
I didn’t even need to go as far as measuring the current drain and removing fuses because I just thought I’d have a poke around and see if I could see anything. I peeked into the boot by folding the seats forward and tadaa – light was on. The switch had got knocked through the plastic so was always on.
We also installed solar chargers in both cars and they’re great! I’m thinking I’ve got space for a couple more on my parcel shelf and it might be enough to charge a separate battery (perhaps a small SLA) which would be used to power an amp or a better stereo of some kind. I never bothered fitting one because the last one I had kept leaving me with a flat battery but given how much time the car spends standing it might be a neat solution.
So thanks very much everyone that was another mystery rapidly solved
Those switch have always been a pain when you least expect it.
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