Jim Chambers

Owners manual says remove it to charge. Is that essential? Or can I just disconnect one or both cables at the battery?
The car is currently under a 4 post lift with a car above and I can't fully open the front lid (assuming I can use a charger in the footwell to open the hood).
I probably can push the car out but can't see why removing the battery completely is necessary. Advice?

911SLOW

You don't have to remove it.

No HTwo O

Use the Cig. lighter and your battery maintainer. May take a few days.

Jim Chambers

I'm wondering if I could have drained the battery with my maintainer. Car sat for a couple of months without a maintainer. Started it about two weeks ago for an exercise drive and it turned slowly so when I got back I plugged the maintainer in. Left it for about a week and then unplugged it about a week ago. Got in the car today and battery is dead. Strange!

No HTwo O

Keep her plugged in at all times. You may need a new battery if not holding a charge. Or maybe you have a parasitic drain someplace.

Jim Chambers

OK, got the hood open using charger on the footwell terminal. Disconnected both cables and have the charger going.
Doubt I have a drain. The car has sat for months with enough juice remaining to start. Started a couple of weeks ago. Then I used the maintainer and now dead (I might have left key in ignition which I think is a drain, but doubt it).
I see that I have a "Porsche" battery. Thinking it may be original. Car has only 22K miles. Battery could be 6+ years old. I'll see what happens after an overnight charge.
Ironic that I use the maintainer (Porsche brand, came with the car) for the first time and I have a problem. Never used it at all last winter while car sat for at least 6 weeks between starts with no problem. Go figure.

No HTwo O

That's a loooooong time in "Porsche Battery Years". Buy a new battery soon.

Macster

Agree. My 02's original battery lasted 6+ years.

I left the car parked for over a week with an OBD code reader plugged in and when I got back into town and went to start the car, while the windows worked but the battery so low it would not crank the engine.

I didn't fool with a battery recharge or anything else, I just went out and bought a new (another Porsche) battery and replaced the old one.

Sincerely,

Macster.

Macster

Leaving the car sit unused for long periods discharges the battery. Lead/acid batteries don't like this treatment, but they have considerable margin and will tolerate it some but at the expense of a shortened life.

At some point though -- after so many years of normal wear/tear and many discharges the battery reaches a point it can no longer do its job.

Replace the battery.

BTW, when you put the car up for the night while you do not have to lock the car, do not leave the key in the ignition.

Actually even when I parked my Boxster in an attached garage I always locked the car. This turns off all the interior lighting, radio, etc. right away. The security system of course becomes active but since my car didn't sit very long unused this was not a problem. If the car sits IIRC 5 days the security system shut down so you have to open the door using the key and then you have to start the engine within IIRC 10 seconds after doing so or the alarm will sound.

Sincerely,

Macster.

No HTwo O

True. It's about 5-7 days. And you DON'T have to start the car. Just turn the key in the ignition, and wake her back up again. If you don't do this within about 30 seconds, the alarm will sound.

If you want to "over ride" this sleep mode, just hit your key fob lock every 4-5 days, and the cycle resets.

Jim Chambers

Macster, why a Porsche branded battery? My assumption is it will cost much more than a ordinary brand (Interstate, Costco, etc). Is it worth it? Or am I wrong about the cost difference.

smlporsche

Of course the Porsche battery will cost more, silly!

OTOH there is something about the orientation of that battery that is hard to replicate from what I remember, although it has been done.

I still have the original battery in my '03 but it is on a maintainer whenever is is parked (I am on borrowed time !)

Jim Chambers

Time for research. Had the charger on for 18 hours and it is still putting out 4 amps. By now it should have finished its work. Today is battery shopping day.

mikefocke

You left it sitting. It ran down and damaged the battery. You had just enough to start. But didn't fully charge it and the battery couldn't take a full charge at that point anyway. You connected the maintainer. But the maintainer only comes on when the voltage in the battery is at a certain level and yours wasn't. Thus the maintainer never came on and it was pure coincidence that the next start failed. The reason for not changing the battery is that, if the battery lacks "water", it can explode when you attempt to charge it or just heat up so much it will damage your trunk lid. Did that once on an Alfa and it burnt the trunk fender paint where the battery was located.

Jim Chambers

Thanks all.
Just bought a new battery. Used the data from your site Mike. Called several sources (P. dealer, $234) and all the auto parts stores in town recommended the group 48. Was about ready to buy a 70 Ah group 48 European OE at Carquest for $112. Noticed they had a 94R which was 80 Ah and looked exactly like the Moll that came out of my car (tiptronic). The 48 was smaller. Only exterior difference is the case is black instead of white. Has the same handles and case looks like it came from the same mold as the Moll. Their price was $151.99. When I began to consider it instead of the 48 the counter man said I will let you have it for $130. Sold!

Lesson learned. I will use the maintainer if the car is setting for more than a week.

The green light on the maintainer never went to full charge even after a week. Guess that is evidence of battery being unwilling to accept a charge.

Edit: learned that battery I bought is US made by East Penn and branded Deka or store brands. Both the 48 and 94 R are exact replacements for OE battery.