Flat battery

[Chris-mac]

My 993 has been stood in the garage for about 6 weeks, with the doors unlocked and no alarm set yet when I came to start it this morning, nothing, just dim dash lights.

The battery isn't very old,

Does anyone have any ideas what saps the power and how I can solve the problem?

Chris

[LordHaveMurci]

You can solve the problem by driving it!

[Chris-mac]

I do drive it most of the time but I've just been having building work done, so I could only use it if I was prepared to park it at the roadside and that's not an option, I'd rather have a flat battery than a wing mirror missing or a scrape down the side.

[CarreraLightweightRacing]

6 weeks without use; I'd be surprised if it had enough juice to crank the motor over. You could stick a voltmeter over the terminals to check how fast it is losing volts. As an example I am currently using a small race battery (Odyssey PC680)in a 996 and it is dropping approx. 0.15Volt per day in the same configuration you mention.

[Cedric's Dad]

Mine has always discharged within 3 weeks so is now it is plugged into a Ctek battery conditioner. Worth a look!

[Chris-mac]

I'm shocked at the rate of discharge, I was almost convinced that there was a light on in the bonnet or boot area but you have all confirmed this not to be the case.

I have an optimate for my bike, so that is currently hooked up to the 993 to trickle some charge back in.

[86wasagoodyear]

+1 for a trickle charger. Worth the money. I have a Carrera 3.2 that I keep on a charger. Never misses a beat, not even over winters when it might not be fired up for a couple of months.

[drmark]

If it has a Porsche battery look no further - they are crap. Bosch S5 - go for the higher amperage one - and you won't look back. You can leave the thing for ages.

[AW10]

If you have a digital voltmeter with a current measuring mode you can connect it in series with the battery and see what the actual current draw is.

Also check that with the ignition off and the doors shut the windows `*don't* work. If they do then the window relay is being energised (probably by a faulty door switch) and that will kill the battery.

[swimd]

drmark said:

If it has a Porsche battery look no further - they are crap. Bosch S5 - go for the higher amperage one - and you won't look back. You can leave the thing for ages.

Seconded. I use Bosch or Varta (same product, different label) in all of my cars.

If you don't drive the car often it is also worth looking into a battery master switch.
I had one installed my older 911 and I'm convinced I could let it sit for a full year without charging and it would start right up again. It also acts as a crude form of theft prevention.

[ClaphamGT3]

Even back in the day my 993 would flatten its battery in two to three weeks if left unused. 6 weeks doesn't sound like anything to worry about

[Chris-mac]

With the Optimate connected it has topped the battery up and the car starts fine, I'll just have to alternate the charger between the car on the bike or splash out on a second.

Thanks for everyone's input, it looks like I have a normal car.

[LordHaveMurci]

Chris-mac said:

With the Optimate connected it has topped the battery up and the car starts fine, I'll just have to alternate the charger between the car on the bike or splash out on a second.

Thanks for everyone's input, it looks like I have a normal car.

Amazon have regular deals on C-Teks - I bought an MX5-S for my 996 as it goes flat in 2 weeks.

[Fl0pp3r]

Tripple seconded - CTEKs rule.