wemkehou

I have a similar problem on my 99 911 (996). I have had two bad batteries in the last 15 months. The current (dead?) battery is from the Porsche dealer (Bosch) and was only 8 months old....and the dealer will not offer any warranty. :angry: Before I replace another battery (probably from Costco), I have a few additional symptoms: 1. My trip odometer and clock reset when I do my first attempt to start the car (with or without a battery booster pack connected). It usually will crank once and fail to start. Further immediate attempts to turn the ignition key result in a relay-clicking sound but not for more than a few seconds and definitely no engine crank. I usually see the voltmeter on the dash drop from 11.8 down to 11 volts once the short cranks fail to start the engine. 2. If I am lucky and wait about 30 seconds with the ignition turned off and a battery booster connected, I can usually get the car to start, albeit with a weak initial crank. 3. The voltmeter on the dash shows 14 volts once the engine starts and then usually drops down to 13 volts after 15 minutes of driving. Once I saw it drop when I turned on my headlights, but it may have just been coincidence with 15 minutes. 4. After even 45 minutes of highway driving, I am uable to immediately restart the car after turning the engine off. 5. The Porsche dealer did a current draw check when I got the last battery and found a slightly higher draw (100 ma vs 50 ma expected) but did not think it could cause problems. I also have an aftermarket iPod hookup. 6. I now have both a Porsche battery maintainer and a battery charger. The charger seems to show the battery is fully charged but I still need a battery booster pack to get the car started. I was going to start a new post but I thought I might have the same problem. Any feedback would be appreciated. I am really impressed by the discussions on renntech.org. :renntech: Thanks!