generator size for A/C

Hi DavisK,

Why not just use a parallel kit, conjoining the 1k and 2k Honda units?

DavisK wrote:
I have a Honda 1000 and a 2000, but neither will run the A/C.

I have a Yamaha 2800 inverter generator. It runs the 13,500 AC fine. I have yet to try it on the 15,000 AC. Since the bigger AC is about 8 years newer, I think it is probably more efficient and I expect the generator will run it fine.

When I used it on last TT, it ran the 13.5 AC, a few lights and the TV fine at the same time. You would obviously have to turn off AC to run microwave, coffee maker, or hair dryer.

I would not buy less than 2800 watts if I wanted to make sure the AC ran. I know the 2400 watt Yamaha is hit and miss on running AC based on forum reading. Hope this helps.

DavisK wrote:
I have a Honda 1000 and a 2000, but neither will run the A/C. When I need to run the A/C on a generator I take along one of these Champion 4000W RV generator. I didn't get mine from Amazon.

Best place I found for the Champs including free shipping is supergen products.

I have a Honda 1000 and a 2000, but neither will run the A/C. When I need to run the A/C on a generator I take along one of these Champion 4000W RV generator. I didn't get mine from Amazon.

The Champion looks like the best for most that don't have a built in generator.
I have a Honda 2000 and it barely runs my 7200 BTU A/C. I have to turn off the inverter to be safe.
34.2 locked rotor amps (LRA). 11 amps total with comp.and fan running.

IMO, you need a generator (or two generators paralleled) that produces at least 2800 continuous watts (not surge or peak watts) of power in order to power a 13,500 BTU RV a/c with a very high success rate. In order to do this reliably and consistently (especially with a 2800-3000 watt generator), all other 110 volt appliances in your RV, including your converter, should be turned off.

Many have good luck powering their 13,500 BTU a/c's with the Yamaha EF2400ISHC generator (2400 watts continuous) which is an outstanding generator with outstanding sound level specs. However, there is a small minority that cannot. For those folks, they have to resort to changing capacitors in their a/c unit or getting another generator. For some, this is too big of risk when you're spending $1400 (street price).

In order to make sense of fuel consumption rates you have to know time, amount of fuel consumed, and load. Unfortunately, many manufacturers are vague about loads. Usually a call to the manufacturer will get you this information.

However, not all RV air conditioner units are "the same".

There are high efficiency (HE) 13.5K BTU RV air conditioners that might start and run on a Honda 2000i inverter generator just fine. However these type air conditioners are very rarely found in run-of-the-mill RVs as delivered by their manufacturers.

FWIW, if our RV's "standard" 13.5K BTU air conditioner ever gave up the ghost, I'd replace it with an HE model.

I tested my 2400 before going to a Atlanta race and it ran the AC in my 5er. Got to the race on a hot day and even revving it way up it would not start it. Your mileage may be better but when the AC will not start you'll wish you had another couple hundred watts.

There is no way on earth you will be able to run an AC on a 1000 watt generator, for although the AC running continuously uses only around 700 watts of power, every time the compressor starts, it will draw around 2,000 watts for a couple seconds, and that is beyond the capacity of a 1000 watt generator.

Add in the fact that your converter will be drawing something to recharge the battery (amount varies due to the state of charge on that battery), and even a 2000 watt generator becomes very iffy indeed.

At a bare minimum, you need 2400 watts. But that is still going to be taxing that generator hard, thus likely shortening its useful life. I would recommend strongly nothing smaller than a 3000 watt unit.

Champion 3100i $950 delivered




3100 Max Watts
2800 Running Watts
TT-30R RV Outlet
True sine wave inverter technology
Economy mode to save fuel
Overload protection
120V AC Load
12V DC outlet
Up to 8 hours run time at 25% load
58 dBA at 23 ft.
Built-in Wheel Kit and Handle
Easy pull recoil start
Low oil shut-off sensor
USDA approved spark arrestor
Battery Charging Cables Included
Gross Weight: 92.6 lb.(42 kg)
Net Weight: 83.8 lb. (38 kg)