(T) My battery-destroying Punto

Hi all, I've got a 2002 1.2 16v Punto Sporting which is going through batteries at a rate of knots.
The problem started when my Punto would have a flat battery if not driven for a couple of days or so. I thought it was either the battery coming to the end of its life, or something draining the battery. Either way I called the AA out, and the guy did all his tests on it... alternator fine, battery taking the charge fine, nothing draining the battery when the engine's off. He plugged his little handheld diagnostic thing in and it just said 'replace battery' straight away. I was a little miffed as the battery was only a year old or so, but I got a new battery fitted anyway.

A month down the line, and same problem - battery is completely dead if I haven't touched it for a couple of days. Same AA man came out, exactly the same happens again - everything else checks out fine but says battery needs replacing ASAP. Repeat this process several times, and the garage is getting annoyed at me abusing my battery warranty. Except the garage's diagnostics keep saying the battery is fine, working at 90%+.

If its something draining the battery (I suspect the stereo) this doesn't explain why the battery apparently 'needs replacing' constantly, and it should just need re-charging which doesn't seem to do the trick. I don't understand! Anyone had a similar problem?

Thanks

silly but worth a try when you park the car up for a few days take the head unit out and see what happens

i agree, i don't see why the battery would need replacing every time but if you take the head unit out you can at least rule that out.

Yeah, I'm going to take that out tomorrow and see if that does the trick. Im sceptical though.

Stop using the AA, get a meter, remove the earth lead from the battery and place the meter between the earth post and earth lead.

Set to amps, and report the reading.

Cheers

SPD

ive got a similar problem with my punto.. but my battery only gets drained as soon as i switch on the ignition.

Also get the generator tested. If the voltage regulator is going home, the battery gets cooked. In the meantime disconnect the earth lead overnight and see if it stops going flat.

ive already done that and the voltage stays the same... mine only drops when i turn the ignition

If you are sure the gennie is ok, it could be a faulty battery. Assuming you bought it new - take it back. The supplier will want to test the electrical system so make really sure its all ok before he replaces the "old" battery. If its showing more than 14.2 volts, he'll say its not the battery's fault.

ok. im thinking of going to kwik fit tomorrow cause they say they do free battery checks so ill see what they say

Does your headunit have a backlight or lit-up digits that stay on permenantly even when ignition is switched off?
I had one of those and it cost me a new battery. :@ Make sure it's 12v and there's no additional backlights.

I only have a cheapy Sendai one from Halfords but it does the job, plays CDs and has a radio tuner, don't need much else.
It has a backlight but the backlight turns off when unit is switched off or fascia removed.

Get a headunit with a removable fascia if you find it is the headunit that's the root of your problems.

Heres one --- I bought a new radio/cd player so I took the factory fitted one out and put in the new one, lovely sound. Then problems with flat battery, I went through the usual tests and in the end I rewired the radio so that it was off for certain when the ignition was switched off and that cured it.
This may not be your problem but its worth noting
Best of luck