Battery Drain Pain!

[TimC]

After leaving my 180 ZTT for a few days the battery goes totally flat.
I replaced the battery - under warranty - and it still happens.
It gets so flat that the interior lights won't turn on.

I've fully charged the battery and left the car for a few days without locking it and it still goes flat

Any ideas?

Cheers,

Tim

[mikesmith2]

Have you added any thing electrical, obviously something is drawing power all the time.

It could be the boot light even

[TimC]

No changes to the car, just started doing it.
I thought it was a duff battery hence changing it for a new one but still the same.
I've checked for lights left on but nothing.

[Rocket]

If you have sat nav - check that it shuts down.

[chrissyboy]

one of the modules aint going to sleep .with a multi meter you can see what is being drawn ,then unplug each module till you see a drop in the reading ,that wll be the module that is drawing the power .

[HarryM1BYT]

Originally Posted by mikesmith2

Have you added any thing electrical, obviously something is drawing power all the time.

It could be the boot light even

It should not be boot light, glove box light or interior lights. These are all controlled by a battery saver system, which isolates power to them is they are accidently left on 20 or so minutes after the car is left undisturbed. It might be worth checking this is functioning, by leaving a door or boot lid open and confirming that the light does in fact go out.

One check you could try, is wiring a headlamp bulb first then a 21w lamp across FL3 in the underbonnet fuse panel, instead of the 50amp fuse. The lamps should go out, if there is no loading on the fuse. That fuse is the one which supplies most of the things which have their supplies to them maintained, when the car is otherwise all (supposedly) turned off.

[SteveT]

I would begin by using an ammeter to confirm that there is, indeed, current being drawn from the battery when everything is off. I'd use my multimeter on its 10A range, connected in series at the battery earth terminal.

By measuring the current you might even get a clue as to what is causing it. For instance, 2A would suggest a 25W bulb. 0.42A would suggest a 5W bulb. This might help you home in.

Then you can start removing fuses one at a time until the drain disappears. This will give you a very strong clue to where the problem is.

Obviously don't switch on the ignition or try to start the car with your multimeter in circuit, as you'll blow the fuse in the multimeter (not a major problem, but inconvenient all the same).

Steve

[HarryM1BYT]

Current drawn by the car should fall within 30 minutes or so, down to approximately 30mA or 0.030 Amps depending upon model, but car must be left undisturbed for that to happen (no doors or switches touched).

[TimC]

Originally Posted by Rocket

If you have sat nav - check that it shuts down.

Thanks for the replies guys.

Sat Nav red light stays on after tuning the car off. Is this correct or is it not shutting down?

I'll need to buy a new multimeter is a DVM OK?

[samurai]

When you put the ammeter in series with the negative lead of the battery , and you disconnect but it still does not remove the drain , then i would say try disconnecting the alternator , i have seen the rectifier cause this problem .