I took my car out of storage on Friday and brought it in to install my H&R springs and had a hard time starting the car after it's hibernation this winter. I had the car in a heated garage, under a cover and plugged into the Porsche battery tender. I took the car for a good 30-35min drive to try to charge the battery before bringing in the car for the suspension. So after the spring install the car was dead so I jumped it and drove it around again and put it in my garage at home thinking that I might need a new battery. After speaking to the dealer and them telling me that it was tough to pass a battery under warranty, I was a bit peeved since I had done everything I should have...and a new battery is $285.
Long story short(er), it turns out that my tender was defective from the get go and it was never really charging the battery at all. It is supposed to put out 15amps and was only putting out 100milli-amps. Aha!
The dealer has my car and is charging the battery or replacing it if it does not work and clearing of the codes.
On top of that, my BMW's battery died today as well and I had to get a new one for that. When it rains it pours!
Jeez. If the tender was defective and you got it from a Porsche dealer then I think a good dealer would comp you a battery. Good luck!
(My Porsche charger shows a green light when the battery is charged. Did you happened to notice this?)
That cannot be right. If you have the new Porsche battery tender, it says max is 3.3 Amps. 15 AMPS is not a tender ... that would be a real charger.
I am a bit surprised that you were able to start the car in the first place - if it was in storage for about 3 months, the battery would be dead ( I assume the car was left unlocked during the storage time, as otherwise it would be drawing a lot of power ).
The other possibility is that your batter tender died recently ( read few weeks ), and was working before that. In my case I was using a regular battery charger, with a timer that switched it on for few hours each day - I checked the battery from time to time, and the voltage was about 12.75V. Also, in order to avoid moisture buildup in the car, I had no cover, and the windows were left open.
Good luck with the car - lets hope you have it back soon - I know how much one looks forward to driving it after the looooooooooong winter ;-) ( Ok - so this year the Winter was a bit shorter, but still ... )
P.S. I dig up a link I had on good battery info - a lot of good info there:
http://www.uuhome.de/william.darden/carfaq.htm
$285 for a battery?????!! What's with that.
