Should charging volts drop when headlights on?

[JP911]

I recently installed a voltmeter gauge after experiencing some electrical problems and I've noticed that when I turn the headlights on the charging voltage drops from approx 14 to 13.5 volts, and when I turn on the fogs it drops a bit more. Is this normal?

[North Coast Cab]

Yes. As the load increases the voltage tends to drop. As long as you're running at least about 12v you'll be fine. If it gets lower you can harm your alternator.

John

[kqw]

Normal.....

[JP911]

Thanks for the quick responses! I've just become a nervous-Nelly after having what I think was a bad Optima. The battery wouldn't hold a charge and was replaced for free under warranty (batt. was 6 months old). I installed one of those fused battery disconnects and I use it almost every time I park the car for more than a day. Lately, the tach has been bouncing a tiny bit (pulsing) and this now has me nervous...

[Zeke]

Bouncy tach is because of ?? I missed that one.

[singpilot]

All normal. I disconnect mine if longer than a day or two. Same volts with the lights. Even lower with the air on high.