[Brobrian]

How long can I run my lights on these long winter nights while the ammeter reads -10 amps?

I've been meaning to ask this question ever since the shorter days have forced me to drive with my lights on. I drive to work in the dark and notice that with the lights on my ammeter reads -10. On the way home with the lights off, it charges at about 3 or so. The car starts so quickly that I can't tell if I'm slowly draining the battery just by listening to it turn over. Heck, for all I know when the battery gets low enough the alternator will boost it's charge rate. I've seen the meter read +20 when I first turn the lights on in the morning. But only for a second, then it runs a 10 amp discharge the rest of the drive to work. That rate doesn't change much no matter the rpm.

I seem to remember with my last alternator that the car never ran at a discharge.

Oh, I'm using 6v 30 amp alternator from Snyders. And, yes, it's properly installed, as is the ammeter in the dash.