I usually kill it around 220, but its seen 230-240... mechanical, its at the hottest point out of eng. going back to rad...back to the question, """I want to wire in some fans, & the guys at my local electronics store don't have a clue (neither do I), what do i need to look for in a regulator/rectifier, rectirfier bridge...does this set up charge the battery also, or just help run the lights .I will only be using the fan for 1 min at a time, every 10 min's or so ...do i have to float the ground to run the fans?"""