Community Forums

PEPPER9950 · 11-01-2010, 04:01 PM

What size inverter and how many house batteries would i need to run 2 13500btu rooftop a/c's,1 satelitte receiver and 1 tv for 4-5 hours? TIA

94-Newmar · 11-01-2010, 04:57 PM

You wont be running any A/C's off of an inverter! You dont have enough physical room to mount one that big, nor enough battery.... the standard size found in most is around 2000 watts. But to figure out how much you'd really need you need to know the A/C start up amperage. Once you have that your basic equation is watts = amps x volts. So if you had 2 roof A/C's each drawing 20 amp on startup you'd need 40 amps. 40 x 115 = 4600 watts. That is a BIG inverter. My best guesstimate would be that you would need at least 10 batteries to handle that for even a short period of time.

For the price you'd pay for the inverter plus the batteries I'd suggest just purchasing a nice 5500 watt quiet generator - would be much more cost effective.

PEPPER9950 · 11-01-2010, 06:07 PM

thank you Newmar

Gary RVRoamer · 11-01-2010, 07:56 PM

I have actually read about an RV that has enough inverter & battery to run two a/c units, but it was owned by Saudi prince who can afford it. It had multiple 4000 watt inverters and something like 10-12 huge 8D batteries. That's the equivalent of 20+ 12v batteries. You get the idea...

It makes a whole lot more sense to run the generator when you nee a/c.

B Bob · 11-01-2010, 09:47 PM

You would need a billion. LOL. Or at least a whole bunch. Plus a line up of inverters.

RV Wizard · 11-02-2010, 02:33 AM

In school we ran a 13.5 BTU air conditioner off of a single 2500 watt inverter and a group 27 battery for a few minutes just to show the class how an inverter works.