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[marko2002]

Having worked as a trainee auto spark for about a year some time ago it was always these "niggles" that were the worst to diagnose although generally most people did have problems starting their car hence why they were at us but if you can start your car each morning without a problem and without the starter feeling sluggish I'd say the alternator is charging great and the battery is holding the charge but if your having problems starting after a few days of non use I'd be inclined to check interior lights (usually the one's most at fault were likes of glove box lights or boot lights).   Locate the switches for these and press them (i.e. the switch which is depressed when you shut them) and obviously the light should go out, although for the boot it wasn't the first time we had to climb into the bloody things and get someone to shut them over to see if the light went out - maybe that's just cause we were trainee's mind u!!.

Decent auto sparks will run a serious of checks for you including a battery drain test although if it's new chances are the battery is OK and something else is causing probs, but I'd start with interior lights.

[Auto Addict]

Having worked as a trainee auto spark for about a year some time ago it was always these "niggles" that were the worst to diagnose although generally most people did have problems starting their car hence why they were at us but if you can start your car each morning without a problem and without the starter feeling sluggish I'd say the alternator is charging great and the battery is holding the charge but if your having problems starting after a few days of non use I'd be inclined to check interior lights (usually the one's most at fault were likes of glove box lights or boot lights).   Locate the switches for these and press them (i.e. the switch which is depressed when you shut them) and obviously the light should go out, although for the boot it wasn't the first time we had to climb into the bloody things and get someone to shut them over to see if the light went out - maybe that's just cause we were trainee's mind u!!.

Decent auto sparks will run a serious of checks for you including a battery drain test although if it's new chances are the battery is OK and something else is causing probs, but I'd start with interior lights.

Cheers, I'll check, when it stops raining

[Auto Addict]

Checked all the obvious, no lights being left on anywhere.

Seems to drain by 0.5v per 12 hours (left standing).

Is this normal?

[Kevin Wood]

Seems to drain by 0.5v per 12 hours (left standing).

The voltage doesn't really tell you much, to be honest. It will fall rapidly after driving and then settle to a prett6y constant value, IME. It also depends if you've got any load on the battery when measuring it.

If you're still concerned, put an ammeter in series with the battery (start on the highest range - 10 or 20 amps and be very careful not to turn on any heavy loads with it connected). Shut the doors and leave the car for 10 minutes or so, then drop the range on the ammeter until you can get an accurate reading of the current. You should find it's tens of milliamps. Certainly more than 100mA and I would be concerned.

If you think you've got a problem you can then start pulling fuses to eliminate circuits.

Kevin

[Auto Addict]

Seems to drain by 0.5v per 12 hours (left standing).

The voltage doesn't really tell you much, to be honest. It will fall rapidly after driving and then settle to a prett6y constant value, IME. It also depends if you've got any load on the battery when measuring it.

If you're still concerned, put an ammeter in series with the battery (start on the highest range - 10 or 20 amps and be very careful not to turn on any heavy loads with it connected). Shut the doors and leave the car for 10 minutes or so, then drop the range on the ammeter until you can get an accurate reading of the current. You should find it's tens of milliamps. Certainly more than 100mA and I would be concerned.

If you think you've got a problem you can then start pulling fuses to eliminate circuits.

Kevin

I've tried my multimeter accross the + and -, with it set to 10amps (max it will go), and I get an 'Out of range' reading.

[Kevin Wood]

I've tried my multimeter accross the + and -, with it set to 10amps (max it will go), and I get an 'Out of range' reading.

On the amps range you need it in series with the battery. I.E. take the positive lead off the battery, one meter lead on the battery terminal, and one on the clamp that came off.

Connecting directly across the battery will short it out  You may find it's blown the protective fuse in the multimeter.

Kevin

[Auto Addict]

I've tried my multimeter accross the + and -, with it set to 10amps (max it will go), and I get an 'Out of range' reading.

On the amps range you need it in series with the battery. I.E. take the positive lead off the battery, one meter lead on the battery terminal, and one on the clamp that came off.

Connecting directly across the battery will short it out  You may find it's blown the protective fuse in the multimeter.

Kevin

 

[Debs.]

Just a thought:
I owned a car with a fault in an alternator diode which caused the alternator to get ever-so slightly warm when the ignition was turned off.

[Kevin Wood]

Just a thought:
I owned a car with a fault in an alternator diode which caused the alternator to get ever-so slightly warm when the ignition was turned off.

Good point.   I have seen alternators where the diodes go leaky and result in a gradual discharge of the battery.

Kevin

[Auto Addict]

Right, disconnected the battery, set meter to 10amp (which says will give a reading between 400ma - 10amp) got a reading of 0.361, which I presume is the power sounder??

Set the meter to ma, got no reading at all.

[Kevin Wood]

got a reading of 0.361

OK. Leave the meter on for a few minutes with all the doors closed and the keys out because there is a time delay relay that takes a few minutes to drop out. You may be looking at the current that's taking. See if it drops. If it doesn't drop I'd say you've got a problem with something.

Doers your power sounder work? (I.E. go off with the alarm and if the battery is disconnected?)

Kevin

[Auto Addict]

got a reading of 0.361

OK. Leave the meter on for a few minutes with all the doors closed and the keys out because there is a time delay relay that takes a few minutes to drop out. You may be looking at the current that's taking. See if it drops. If it doesn't drop I'd say you've got a problem with something.

Doers your power sounder work? (I.E. go off with the alarm and if the battery is disconnected?)

Kevin

Disconneted the battery, left it for 10mins.

Set meter to 10amps, connected in series, power sounder blipped.

Took the reading, display didn't vary, disconnected the meter, power sounder went off.

All doors were closed, and keys out of ingnition.

[TheBoy]

AA - connect ammeter as before, 10A range. Leave for 20mins, then post back reading (ie, leave ammeter connected for those 20mins)

[Auto Addict]

AA - connect ammeter as before, 10A range. Leave for 20mins, then post back reading (ie, leave ammeter connected for those 20mins)

Will do.

[Auto Addict]

AA - connect ammeter as before, 10A range. Leave for 20mins, then post back reading (ie, leave ammeter connected for those 20mins)

Will do.

Readings after 20mins:-

Fluctuates between 0.014 - 0.032