On 11/6/06, Martin K wrote: > > On most cars the alternator spins faster than the engine. The alternator > should be supplying energy to the battery at idle speed, it makes no > sense for it not to (as you imply). For the typical car idling at 1000 > RPM, the alternator might be going about 1.5k - 2k RPM. I have no idea > where he got the 7k - 9k number, that's ridiculous for anything but a > race car or a rotary engine. 1500 ish is typical for passenger car idle. I've set mine as low as 600, which saves gas pretty nicely. The alternator absolutely does output plenty at idle. I've sat for many hours with AC, lights, strobes, and radios running, and the battery voltage is still >13V as it should be. And this is a stock passenger car, not a police model. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist