Using a portable ac with a inverter

Look at the Watts your A/c will draw (written on sticker on it.). Now divide it by .80 which is approx the power loss of the inverter. Now you have you usage in DC. (make sure the inverter is rated high enough to cover this wattage) You will want agm batts since starter batts don't like constant cycling or draining bellow 70%. Agm can handle "hotel" loads much better. Now you say you want to run a battery charger. If the charger can charge the batss at a higher wattage then your draining, you wont drain the batts. What is powering the charger? If your plugging the charger in to land power, why not just plug ac into land power and save 20% int he loss? If your charging from solar or something like that, you wont have enough power to keep them from draining.

 

For that just get a generator..

 

If you are using the Honda 2000 it has to have the Eco-mode turned off until the a/c compressor turns on. It won't rev up fast enough in Eco-mode. Once the compressor is going, you can switch it back to Eco-mode. Also, if you need an extension cord, make sure it is only the length you need it and a heavy gauge wire. I am running an 8000 btu LG unit and the Honda 2000 watt generator. Working very well for me. Only complaint - fuel tank needs to be bigger on generator. I get about 7 hours out of each tank on Eco-mode. It holds about 1.1 gallon. I carry two small 1.25 gallon jerry cans and the setup is working well. I am also looking into an extended run system so I don't have to fill it up in the middle of the night when it's hot even at night.

 

the a/c i had was 350 watts. but the peak was over 2000 watts. to get that compressor initially started.

also, you can not run a charger off the very sourse it's charging. you get loud hissing noises and burned out chargers. been there, done it.

you can buy cheap 800 watt generators from harbor freight for $80 when they are on sale. but you do need 2 stroke motor oil to mix with the gas.
you can also buy cheap battery chargers. mine was on sale for $40. 2/10/50 amps.

 

An inverter is good for either small low wattage uses or large short term usages. A generator is better to run an air conditioner. The facts are that it will take a lot of house batteries to run an air conditioner for 10 hours. The generator will weigh less and probably be smaller.