Watts Help Needed.

A standard 12V battery will have around 90 amps and you can only use about half of that so 45 amps else you will shorten the life of the battery.

You would be using the 1.8A number at 12V.

Ryan

I would round up to 3 amps and call it 15 hours.

That will be plenty I think. Pretty much all I will be doing is the TV and maybe charging two cell phones. I'm also getting the Westinghouse iGen1200 generator. It's a 1000 watt and 1200 watt peak. I'm guessing the max amp battery charger would be 8 amps this generator could handle. I would probably get a 5 amp battery charger and then run the generator 2 to 3 hours or less a day to top of the battery. Almost forgot the 650 watt coffee maker to make a cup or two a day. That shouldn't be to much at 600 watts for about 3 minutes a cup.

Jim

Divide watts by 10 to get amps @ 12 volts.

Divide amp-hours of capacity by 2 to get usable amp-hours.

don't confuse DC amps and AC amps

a 5 amp charge at 13v+ is only 65 watts

8 amps at 120v input too a battery charger or converter is 960 watts

you want a charger/converter between 30 and 45 amps DC charge

500 to 700 watts of charging

5 to 10 amps of charging will take days to recharge/replace what you use

Inverters at low percentage of potential percentage of power are sooey-sooey pig-pig hogs of power. You are forgetting the 20% Charge Efficiency Factorial. 20% vigorish the battery charges for loans. Do all your VA calculations then add the 30% minimum replenishment energy premium.

I wish it was more efficient.

YOu need to add an amp for the inverter overhead

But when you say 1 12 volt battery.... Well that can be anything from a couple amp hours to over a thousand. Just so you know

Minimum recommended for a 1,000 watt inverter is 200 amp hours.

You want to look at a battery's reserve capacity rather than amp hours.

Forget the coffee maker when on battery power only.

The 22w with inverter drawing 2.5 amps is at half the 20hr rate of a 100AH battery, so you get longer time than just using down to 50% (50AH) due to Peukert.

You get "inverter amps creep" upwards as battery voltage falls when the inverter tries to maintain the watts, so that 2.5 amps could end up as 3 amps after a while. This will reduce the Peukert difference from the 20 hour rate as time goes on. Still more time though.

The big inverter vs small inverter for small loads was gospel, but when I measured for that in some tests I posted about a few years ago, it turned out not to matter. It was because the small inverter was on thinner wires to the battery than the big inverter, so it was a wash. Especially if the small inverter is plugged into the Winegard 12v socket.

Also you can't compare inverters in inverter/chargers with ordinary inverters. Those inverter/ chargers have big draws to run their fancy features just on standby, that ordinary inverters do not have.