So, I've been pretty successful with Battery Tender car charger with my BMW;
http://batterytender.com/product_info.php?products_id=2

Since we don't drive our Cayenne daily, thought it would be worth to charge the battery while parked in the garage.
Typically the light indicator turns into "Green = maintenance" mode once it thinks the battery is fully charged after over night charge w/ my BMW; but with my Cayenne, I begun charging around 9am and checked throughout the day and decided to pull the plug around 9pm, that's 12hrs of charging! and afraid that it might over charge the battery. (who knows.... )
Or did my battery really need to be charged that long? I just didn't feel comfortable leaving it plugged while I'm on the bed waking up with fire in the garage, I don' know.

Does anyone here have an experience with battery tender brand car battery charger on Cayenne? I know Porsche has their own version of battery maintenance tool that you plug in via cigarette socket, but I think they are all same thing as long as charging 12V batteries...

Please advise, thanks in advance!

 

The Battery Tender charges very very slowly, and is designed to turn off when finished. I wouldn't worry about it.



John

 

My experience as well.

 

Oh, okay, thanks for the info; didn't know it charges that slowly.

Yes, it does exactly what you've described above, it turns off when finished, but man,,, I was just kindda worried since it was plugged in for 12hrs but then was still charging.

I'll keep on charging it once I get home.

Thanks again!

 

Both the Battery Tender and the Porsche battery chargers are primarily for battery maintenance not for charging per se. They both will charge, but at a very slow rate. I have both and use them even for just an overnight shot to keep the battery up to snuff. I've had batteries last for up to 6 years with no problem.

 

Good to know, thanks again for the info. I guess the battery in my Cayenne was kindda getting low prior to hook it up to the battery tender (BMW version, but it's basically the same w/ the different label).

 

I use the BMW one on my 996tt... same experience and has worked well... even after I partially ran over it...