[Rev.Vassago]

Originally Posted by SteveBooth

I was just told that running your batteries down then starting the engine to charge them back up takes a real toll on your alternator. Running your inverter and the engine at the same time with some high wattage things going also causes your alternator to work hard.

I had my engine running, a small ceramic 750 watt heater going and a few other small things and my alternator was RED hot. It burned up a few days later and had to be replaced.

I don't know if the mechanic was correct on this issue, just repeating what he said.

I have 4 Optima Yellow Top batteries and I was running the truck off them for 3 days without knowing the alternator was pretty much dead. They recovered every night but on the last day went down to 11.4 volts and the alternator had to be replaced.

The mechanic told you correctly. I've got a heavy duty alternator for my setup (3 yellow top Optimas and an integrated 1800 Watt inverter). Without the heavy duty alternator, I would be dead in the water.

[cdreid]

The average company truck these days has the bare minimum. YOu know.. save that extra 200 bucks on the truck, screw the driver.

If your truck runs a 90 amp alternator it can barely pull a 750w inverter at full power and run the truck. I drive a pete 387 very well maintained and with a 100o watt more than once ive pulled down the batteries while idling to the point it redlighted (course i was slow idling). But you rarely use THAT much power. If you plan on pulling a 1500-2500watt inverter though you need to get a heavy duty alternator on the truck. AS i posted elsewhere a driver suggested a dry cell deep cycle battery (about 240 bucks or more) that will run whatever you want for hours and hours.

For SMALL stuff your batteries can handle it for a long time. Like a 5" 12v tv etc they really barely pull anything. For a laptop, fridge or anything that pulls ac through and inverter though you have to figure conversion loss etc.. they pull a lot of amps out of batteries that arent designed for continuous duty. YOur batteries are designed to operate like a capacitor.. LOTS of amps for a very short time then a long slow recharge.