indesj01

what's up? didn't drive the car for 3 weeks and had to get a jump. after jump found out battery was dead. got a new battery and dropped it at detailer, and it died again after 5 days of in and out of garage driving. mechanic friend thinks it's something "drawing" off battery. any suggestions before I drop it at the dealer? also picking up a trickle charger to avoid future mishaps.

No HTwo O

Don't buy a "trickle charger". Buy a battery maintainer. BIG difference.

FI Flyer

Many -- perhaps all -- of the sockets (lighter and passenger compartment) stay on when the engine is off. And be sure to completely remove the key.

purrybonker

My '06 had a problem with a short in an alternator cable whereby the battery wasn't being charged properly, according to my dealer this is not uncommon.

I had similar symptoms to yours but the dealer caught the alternator problem and repaired it under warranty.

LlBr

PCM unit could be bad. Does it eject CDs okay? Any odd behavior? IOW, if malfunctioning the thing can stay "on" even if the car is parked and key removed.

Da Hapa

in addition to the advice about the battery maintainter make sure you lock your car every time you leave it. Just turning off the ignition leaves a lot of the power on and it will continue to drain your battery pretty quickly.

my dealer advised me when I bought my 08 997S that if I don't intend to drive more than 7,000 miles per year I NEED to get a battery maintainer.

Rambler358

Can someone comment on what this difference is? I always thought they were the same.

luisimo

Ditto, for years I used 'battery tender' on my motorcycles and had been using it on the 911.

Would lle to know the differences, if any.

ADias

A battery maintainer is a controlled charger with circuitry to float the battery once charged, without overcharging. The OEM products do that, as well as CTek and BatteryTender.

No HTwo O

Correct. A "trickle" charger never turns off and "cooks" the battery. Therefore, shortening the battery's life-span.

Rambler358

I have a "Battery Tender" for my motorcycle, and was told it was a trickle charger. Oh well...

No HTwo O

You can buy a Porsche battery maintainer from Sunset for $55. Ask Santa. Done deal!

LlBr

also: check out the Ctek website. They make the battery maintainer for Porsche and others.

http://www.ctek.com/EN-US/Default.aspx

Edgy01

Keep in mind that today's electronically heavy automobiles place an extraordinary demand upon the batteries. Even though I drive my car quite a bit I'm starting to notice some sluggishness in the cranking of my engine. And my environment is as benign as it is--it never gets that cold. My personal test for checking the charge within the car is sort of odd, but worth sharing.

When I first turn the key, I turn it to just short of cranking, so that I can read my oil level (997.1 engine, obviously) but during that 6 second wait I press the SPORT button. When I then go to crank the engine on, sometimes that SPORT button light goes out while doing the cranking. I then have to engage it again once the engine is running. When the battery has a full charge and plenty to spare, those sorts of things should stay as you leave them--and the cranking shouldn't cause them to shut off.

purrybonker

Ditto - also my Durametric unit will show fault codes for sensors like passenger seat airbag relating to voltage drops below threshold. Another handy use for that Durametric - a battery condition monitor!