Problems With Your Battery?

My 06 CS's battery died in the garage after about a year and a half. They towed it in, tested the battery and replaced it under warranty. I drove it regularly and it never sat for long periods. Now I have an 09 CS and this past Friday I got into the car to fire it up and click, click, click. I had driven it the previous Monday with no issues and it sat for 3 days. In December I let it sit for 2 weeks and it started right up on my return. This time they flat bedded the car to the dealer. They charged it up and did a load test and told me everything is fine. I really don't believe that it is going to be fine. I am pretty sure it will die again. I think I remember the Germans losing WW2 because of bad batteries in the Panzer Tanks

You remember the Germans loosing WWII? How old are you? A couple questions: 1. How far do you drive when you start the car up? 2. Do you have an underdrive pulley? 3. Do you lock the car when you store it. If you lock the car, the alarm system will drain the battery a lot faster than when you don't. If you keep the car in a locked garage, just leave the car unlocked. Underdrive pulley will make the alternator turn about 10% slower, so if you're just crawling around in traffic with the heater on, heated seats and rear window defroster plus the Bose radio, well, it probably won't keep up, especially if it's a short trip. Maybe you also keep your headlights on? There was just another thread about a guy who only takes short trips with his CS. We were telling him that the water never boils out of the exhaust system and condensation never boils out of the crank case. You get that brown stuff on your oil filler cap and bits of your exhaust system can rust out. But then there's also the battery thing. It takes about 10 miles of driving to recover from one cold start. At least that's what they used to say. I'm thinking your battery is probably OK, but it's not getting enough charging from the driving you're doing.

I'd try to make them give you a new one if I were you! I just had to pay almost $400 for my battery after only 1.5 years of ownership.

After reading the forums about the batteries and seeing my friend (08 boxter) with a dead batter after not using it for 1.5 weeks I got a battery tender. I plug it in all the time just in case I don't use my car the next day. Two days ago I drove the car 30 miles (15 miles each way) and plugged in the battery tender and 24 hours later the battery was still in charge mode! I bought the CTEK 3300 with the cigarette adaptor...its half the price of the same Porsche OEM one. It only takes a few seconds to plug it in.

I have a 2008 Boxster that I bought less than a year ago with only 20 miles on it. I drive it at least every two weeks during the winter. I drove it on Sunday for over any hour on back roads. Then again on Tuesday for about 30 minutes. On Saturday I tried to start it and nothing. After charging the battery it started. I tried again on Sunday and again it was dead. It had 6200 miles on it. I had it towed to the dealer and they checked the battery and found a dead cell. I was told that they expect you to drive at least 6500 miles a year to keep the battery under warranty. They did put a new battery in under warranty.

My battery did almost 4 years and 20k miles before it gave up the ghost, and I found one cell down. Before paying big money out for a new one, go to an auto store and buy a cheap specific gravity (hydrometer) tester, some distilled water and check the cells and top them up if necessary, and see if you can revive it. If the SG's are in the yellow then all may not be lost, if it's off the scale like mine was then forget it. Obviously if the dealer is going to give you a new one FOC then don't touch your old one otherwise they might change their minds.

Once a year; usually spring, I would top off the battery with water and charge it for a day on my regular 12 volt charger. The battery in my 00 BS lasted 8 years with this procedure and may still be going.

I might break down and get a charger but I still don't understand it. I use my car practically every day just as I did with my previous 2 Audi S4's and never had a battery problem with them. My wife has a Toyota Rav4 and works from home. Some weeks she doesn't drive it for 3 or 4 days, it is 3 years old and no battery issues (or accelerator issues for that matter).

DB: If it's going down that fast, you need a new battery. Have it checked first, then think about investing in a new one. Make sure you get one with the little vent tube and plug the existing clear tube into that or you will get fumes in the front compartment that are quite corrosive. I think Interstate makes them and one or two other brands. The dealer has them for $400 or so if you want to show off to your friends. Odyssey is another good choice. They don't need to be vented, have huge power for their size and are lighter than lead-acid, but you have to rig up a way to fasten it to the car. I think there may be something in Articles about it.

I started my car last Thursday after it had sat in the garage for 4 weeks. It was not locked. No issues at all with starting.

Just for information...I purchased a 2009 Cayman Jan 1, 2010...it had about 300 miles on it...it was built 02-2009....dealer lot for about 7 months....service records note that they replaced the battery just before I took delivery of the car....which means that the factory battery didnt last long....the service guys seem to have a low opinion on original equipment batteries supplied by Porsche

The battery in mine recently refused to hold a charge anymore after two years. Rather than go through the hassle and frustration of trying to get it covered under warranty, I just did what several posted they did in similar threads: Go to Walmart and get an Everstart Maxx 94R battery for $75 (plus refundable core fee). It supports venting systems (be sure to get the red positive terminal cap that includes a plug to close one of the two vents), has higher CCA than OEM, a 3 year replacement and, although longer than OEM, fit the battery tray just fine. Note that some have reported that their battery tray didn't have a threaded hole to fit the battery. Mine was threaded and worked perfectly. Although I understand that having a car sit for long periods is hard on a battery, the short life of Porsche/Moll batteries is very odd. My Mercedes SUV is driven only about 4,000 miles/year and, after 10 years, it's still going strong on the original factory battery.

I have had the car for two years and no battery problem till now. It sat for awhile this winter but started. took it out for a 15 minute drive and back home. I hooked my porsche trikle charger to it because the battery seemed real low when I started it. Tried to start it today and nothing. Got the PMS and tire sensor have failed warning. I hooked the regular charger to the battery and after 30 minutes it said "full charge" which I thought was odd. Got in the car and not even the lights would come on. I live 105 miles from the dealer and it would cost me $225 for them to pick it up on a flat bed truck. I dont think t is worth it when I can get a new interstate MTP H8 for $180. I would think that Porsche would have a better battery than this junker! I'm glad it had enough power so I could open the hood easily!

I'd suspect some contaminated leads. Try taking them off and cleaning them with a wire brush. I had a BMW once that formed some chemical deposit on the battery leads. You couldn't see it, but it insulated the leads allowing a little juice through, but not enough to start the car. One thing to try.

I share your battery woes - I had my 06 Cayman S in storage from Dec to March with a Ctek3300 battery maintainer and the battery died when I tried to start it. The electronics were okay but there wasn't enough juice to crank. Had the car boosted and drove the car for a while and noticed the battery was still weak (rough idle, flickering door light, etc.). Brought the car into the dealership and it turns out the battery had a dead cell and they replaced it under warranty. I should have noticed that the past two weeks the ctek never indicated a full charge that the battery was up to no good. I guess these oem batteries are not that great.

I just had the same problems with my CS 2008 battery. Dead. I jump started it and took it to the dealer. They wouldn't cover it under warranty. I had two choices one to replace it with it Porsche battery ($400.00) or two replace it with an Interstate battery ($297.00) The comment they made was that they had better success with the Interstate Battery. They charged my battery for nothing and said it was holding the charge. Drove it home and two days later went to an autocross after the second run in the first heat guess what car wouldn't start. Monday I going to my local mechanic who has helped me with my Corvette and order and Interstate MTP-8H. It is priced on the internet for $192.00 and see what price he will charge me. The only other car that I had battery problems with was my 1988 Mazda RX-7 within two years. Oh by the way I have a Optima Red in my Corvette and no problems. Looked on line and can't find one that fits the CS.

I replaced my battery in the 07 with a interstate MTP H8. It did end up costing $235 but it has an 85 month warrenty I believe. The only thing that happened was that my air bag warning light went on and would not go off. Ended up driving 225 miles round trip to my dealer. He said the computer had 5 low voltage codes in it because of the old battery. He reset the computer and all is fine. Best of all.....NO CHARGE!:banana: He also said the Porsche Batteries are ( well I can't say the words,but he strongly ment) ****! He gave me the "thumb up" when I told him what I replaced it with.

I just replaced original Moll battery with MTP 91 after first trying the MTP H8as called for in Interstate catalog. Whereas the H8 was considerably heavier and a couple of inches too long, the 91 fit right in. I don't recall cranking power, but don't believe the difference was significant. I was not looking for savings, but MTP 91 was only $125.

I'll be replacing my battery soon. The spec's on the MTP 91 vs MTP H8 as listed in their website: MTP-91 MTP-H8 cca* 700 720 ca** 875 900 rc*** 120 176 warranty 85 85 dimension (11-3/8) x (6-7/8) x (7-1/5) (13-15/16) x (6-7/8) x (7-1/6) * cca cold crank amps @ 0°F ** cranking amps @32°F *** reserve capacity I'm not sure what the stock specifications are but do these numbers make that much of a difference? (sorry for for the alignment issue. I guess tabs do not work.) -Moto

MONK45 So I could have saved some money then! Oh well, I just went with what interstate said and yes,the battery was longer but the mounting tray had holes in it for a longer battery so it worked fine. The only thing I had to do was to put a NUT under the hole so the mounting bracket boldt had something to screw into since the hole was not threaded at all. I guess we need to make this known to all our Cayman fraternity! John

Yeah. I googled Interstate and they were just up the road from me. I definitely prefer the lighter weight one so high in the chassis; not sure about the significance of the reserve capacity. I may find out one cold morning