generator question

[tsanjose]

i was wondering what size generator i need to run my a/c unit? i have a coleman unit that sit's on top of my pup. i don't have the model number handy but does anyone know what the min spec needed in order to run one? can i get away with a honda eu2000?

[nomad_289]

Yamaha ef2400is

[bondebond]

tsanjose,

No one runs an A/C from battery. Not even RoyB. He has a battery bank yielding a total of 255 amp hours. Taking the rule of not dropping below 50% capacity, that leaves 127.5 amp hours.

A typical (Coleman Mach 3) 13.5k BTU air condition runs at 15.3 amps on 120v AC. Using an AC Amp to DC Amps conversion that incorporates the inefficiencies of an inverter (I used THIS site), you end up with a pretty hefty draw on your batteries.

At 168.9 DC amps required to run the air conditioner, RoyB's set up would effectively power the air conditioner for 45 minutes before needing to be shut down and prevent overly discharging the batteries.

There may be some rough calculations and things not taken into account, but you get the idea. The calculations do not even take into account the start-up amps required to get the fan and condenser running.

It's not going to last overnight. A generator would be needed to run an air conditioner.

[tsanjose]

i have a coleman mach1 or mach 3. it's either a 13500 or 15000 btu. if i had to guess, i'd say it's the 1350.

royb, can you send me a link to your set up again? how long can u run your a/c on battery power? for my needs, i'll likely end up at places with hook ups. however, i'd like to be able to watch tv tho so im looking at what i'd need to power the most power hungry item i have (ac) then scale back.

[bondebond]

Did you measure the voltage during start up and run times? Were you able to do so without installing a hard start capacitor? By any chance did you have a Carrier AirV air conditioner?

[PopBeavers]

When I still had my Trailmanor I was able to run the 13,500 BTU a/c on a single Honda 2000 at sea level if I turned off the converter and all other power consumers.

[exeter_acres]

would need to know the size of the AC to answer....

[RoyB]

My 2KW Honda EU2000i will NOT run mine sitting on top of my POPUP... I have the 13,500 BTU model.

I never could find any public place that would even allow me to run my generator more than a few hours a day here on the east side of the US. With this in mind I beefed up the battery system to run all the 120VAC and 12VDC toys we wanted to run in a one day/night camping run off the power grid. I only use my 2KW generator to re-charge my batteries when I am allowed to run one. With the short run times allowed I can only make some coffee or a quick cookup using an electric skillet maybe... Everything gets operated from Inverters and direct connected to the battery bank.

Most public camp grounds allow two hours in the morning and maybe three hours in the early evening. The Natl Forest sites are starting to allow all day from 8AM to 8PM but only allow certain type of forest approved generators... No where can you can run a generator all night long.

Public places must be different around your locations...

Roy Ken

[bondebond]

Basically, a 3,000 watt generator is the minimum size. Some folks report getting the Yamaha ef2400is to run an A/C but it seems to me that it might be rather low on the current.

I have had fine performance with (2) 2,000 watt generators with a parallel kit, yielding 3,000 watts. The A/C starts just fine and runs without issue. There is not a significant drop in the voltage that I have yet measured. Using a pair of generators allows me to use one relatively light-weight generator when I only need to recharge a battery, or both if the A/C is needed but still not having to individually lift a heavy generator.