112344

I own two 911's, a 1989 cab and a 1995 coupe. I store both over the winter in the Northeast. I have both hooked up through the cigarette lighters to Porsche battery tenders. The battery tenders have a red light that comes on when they are trickle charging the battery. The red light on the battery tender hooked up to the 1989 has been on continuously now for about two weeks now, but the red light on the battery tender hooked up to the 1995 does not appear to have ever come on. In fact, I tried a new battery tender on the 1995 with the same result. Am I missing some explanation for this? As far as I know the batteries in both cars had decent charge when I stored them. This just seems strange to me.

Texas993

I occasionally use the Porsche battery tender too. My red light comes on for a couple of days then goes out. It used to have a green light on when the battery was full, but that green light appears to have burned out. So, the little bulb may be burned out on the 993. I find that the charger is warm when charging (red light) and cooler when fully charged (green light).

Cactus

I have the same one and i guess it cycles on and off. I noticed if I open the door it will come on for a while afterward. Seems to be keeping my battery fully charged so no worries.

jimbo3

Measure the output voltage of the chargers as well as the voltage of each battery without the chargers hooked up. That'll tell you all you pretty much everything.

Mine operates like Cactus' and I have no green light. IIRC, Porsche had at least two versions of this type of charger.