I bought a voltmeter to plug into the lighter because my trusty SSE has no voltmeter. On average, I see mid to low 13 volts. I was suprised it was so low. My Optima yellow top and 105 amp reman alternator are about 3 years old, within 3 months of each other.

you do have alot of acc running off that system

Everything was on but the wipers, rear defrost, and the AC. My stereo is 1300 watts, but I turned it off and it had little effect. Turned everything else off, gained about .3V.

And does anyone know a real nice plug in voltmeter? I've got this one from Walmart that isn't lit, but has three leds below the display to indicate voltage range. I want one with lit numbers or a needle.

JC whitney has plug in ones

I found one there. Are there more?

i thing Cyberdyne makes a digital plug in one

Jeez, I drove in town for half an hour with the voltmeter plugged in. Never saw above 12.6V until I got on the highway to go home. I noticed as low as 10.8V momentarily with turn signal, headlights and rear defrost on. But the car seems to be behaving like it normally does. Do I need to try a new ground for my battery or alternator?

Lose the yellowtop. I think it'* had enough time to kill your alternator. It may already be too late for both items.

I'd get a real voltmeter on that to make sure.

Do you ever use the battery alone alot? If you're using the full cycle then like Bill sez, you're alt'* gotta fill a huge battery. If you haven't then it'* just it'* time.

After replacing my alt tonight, i think it was hampering most of the car'* systems. It was lower then I thought it was. Trying to re ground it can't hurt though. Just need a lil sandpaper.

Pretty much never. I used to use the battery by itself, before this one, then it died. Would it help if I took the alt back to Napa where I got it with a lifetime warranty and swap it for the "with heated windshield" model?