Generator Gas Usage, AC, and Battery Charging

Yes, charge rate from generator can vary. I would suggest that you checked that you have a nice 3 stage converter installed to charge your batteries. If not look into a progressive dynamics unit 45 amp or greater and ensure it is set up for 3 stage charging with the charge wizard. My Honda 2000 can run my roof ac but it is a small unit. Not sure of the BTUs, maybe 11000. The Honda is great because it will indeed run for 8 hours, and its rpm will go down as the current demand decreases saving you noise and fuel.

Charge rate to the batteries is highly dependant on these things: battery state of charge, size and length of wire to the converter, and converter amperage output. A Honda 2000 will in fact be able to run a quality 80 amp converter to charge your batteries at 80 amps, provided there is 4 gauge wire to the batteries that is short in length, and if you have enough batteries and low enough state of charge to accept this current. If you only have 1 or 2 batteries, there is no point in a converter with an output higher than 50 amps. This is because the batteries even when heavily discharged wont accept 50 amps for more than a few minutes anyway.


So, in short you may be able to run your roof ac with the Honda 2000 provided that the converter has already charged your batteries most of the way, the fridge is on propane, and no one else is using an appliance at the same time.

BlunderLust wrote:
my main need is to charge the RV batteries. I have read some battery types charge more slowly as the charge approaches 100 percent.

Does anyone know how many AMPS these generators can dump into a battery per hour?

I think the battery type, LITHIUM, AGM, GEL, LEAD ACID impacts this as well. I am OK with paying a premium price for a HONDA, YAMAHA if I get better fuel economy, and product life. But I am a bit concerned that to charge the batteries I might need to run the generator at full power. At full power the fuel usage could increase such that I would be better off with a larger generator which might actually cost less.

1600VA generator will put 60 to 80 amps into the battery depending on the converter, type of battery, number of batteries etc.

Please post your current equipment for best answers on what to upgrade.

You will always be fine on fuel economy with an inverter style generator that throttles down as the charge tapers off. Honda you can get an extended range fuel tank if you want to run the air all day and night without refueling issues.

Moved from technology

To the OP. Your guess that fuel consumption increases dramatically with full load is valid, also the noise level. I use an adapter to plug my trailer into the generator, thereby utilizing my built in charging system. The 2000 Honda will run a 5,000 btu window AC and save gas at the same time since they only require about one third of power of 13.5 roof unit. Have fun.

My two Honda 2000's run my main AC no problem. I bought an extended run gas tank and hook them together. All three full I can get easily about 16 hours without refueling.

Forget charging your batteries without a extra 120v battery charger. One 2K generator is not going to run your roof AC. Buy two or a 3K generator and forget a window unit. 1 gallon if all it is doing is keeping your batteries up at idle through your converter.

BlunderLust wrote:
It seems the Yamaha and Honda 2000 WATT Generators have the lowest fuel consumption. I have read these generators run about 8-10 hours on one gallon of fuel.

Have owners of these generators found the 8-10 hours per gallon to be correct?

I am pretty sure these will not run the 13.5K roof mount AC but I am thinking I could add an auxiliary 8K to 10K window unit while boondocking.

Does anyone have experience with using either (or similar) of these generators with smaller AC units?

Powering a window AC would be great but my main need is to charge the RV batteries. I have read some battery types charge more slowly as the charge approaches 100 percent.

Does anyone know how many AMPS these generators can dump into a battery per hour?

I think the battery type, LITHIUM, AGM, GEL, LEAD ACID impacts this as well. I am OK with paying a premium price for a HONDA, YAMAHA if I get better fuel economy, and product life. But I am a bit concerned that to charge the batteries I might need to run the generator at full power. At full power the fuel usage could increase such that I would be better off with a larger generator which might actually cost less.

The DC outputs on any of these generarors are completely useless. They are extremely low current for the fuel you put into them, somewhere around 6A with ECO mode Off. Plan on a good 3 stage external,charger for any of your battery escapades