So how long is it safe to run the fan while the Jeep is off before I need to worry about draining the battery, 15, 20, 30 minutes???
I don't know, but it would be highly dependent on the shape your battery is in. You could get a very rough, ball park number if you know the amps your fans draw. The battery will have a amp/hr rating. Then there is the formula that I forgot... In any event regular car batteries are not made to be drawn down like that. They're designed for very short high draw applications like starting your car. Drawing them down a good ways will greatly shorten the life of the battery. What you want is a deep cycle battery which are designed to handle being drawn all the way down and recharged. When you replace your battery an Optima Yellow Top is a fine choice. Designed for deep cycling as well as cranking. (holy crap! just went to the Optima North American home page and they have a Challenger on the intro thing). http://www.optimabatteries.com/home.php
30 minutes have always been my experience. However, that is the first time the battery goes dead (while at the track). After that it usually takes less time. haha
Actually, you shouldn't let the battery fall below 11.6-11.7 from what I understand. I've been at the track and used the fans on for a an hour and a half with no issues.
I in stalled my own to the fan. I run it all the time while waiting. I have never had a battery issue.
