Running AC from generator, what wattage do I need?

What size generator do I need to run my AC and few other things in the coach? Would 4000 watts be enough, like two Yamaha’s or something like that?

How are the Harbor Freight inverter generator?

Do you know how many Btu your AC is? It makes a difference but generally I can run my entire rig on a Honda 2200. With the fridge it can be dicey and may have to switch to LP but I can run everything else normally. For me that is one of my two AC’s at a time (not both).

I don’t trust the Harbor Freight generator myself but I will say many many people seem to love it. I would make sure either your credit card or Harbor Freight extended warranty will cover it.

@JessMariano78 you may want to look at this post on the forum. You don’t need a big honkin generator to get the job done. Many of us are successfully running our coaches with AC on with smaller 2kVA generators. I think you should read though @TheSpareTir3’s response here because that EasyStart is a hella product. I have tow of them on my 5th wheel.

I am from the school of though that a Yamaha or Honda is still the best choice. They have well known brands that have stellar reputations in the RV community. Here are two that seem to have success other then the Harbor Freight Predator.

The Generac IQ2000 is fairly new. It appears to be their own engine design that is fairly well made. It can be parallel in the future but rather then buying a second generator you go with the EasyStart you will be fine! The cool part is the Generac has a load meter so you have some idea how hard you are running it.

Now this is the Atima AY2000 which uses a Yamaha engine. This is not to be confused with their less expensive model the SD2000i. The AY2000 is Chinese made so who knows about the longevity of the inverter. My problem with Chinese inverter generators in the past have been things like the choke lever and other parts being made of plastic. They engine vibrates and causes those plastic parts to wear and cause the engine to malfunction. Getting a simple part as a replacement is impossible. I have yet to see one but they seem be all accounts to be a step up from the no name brand Chinese models.

How do you know how many watts that you need to run things? I have a 50a rig and will be at some events this year without shore power options.

So you need to find all AC devices you will be running simultaneously. To get to watts you just need to use the following formula – volts x amps = watts. Now remember you won’t be running everything at the exact same time. You also should consider a little extra amps for the onboard charger especially if the batter is low.

I find 80% of the people I help, they only really need about 2000 watts and are frequently overbuying the generator. The problem with that is not only the upfront cost, the weight and fuel burn with a larger generator. The smaller the unit the better.

Review this reply I gave to a different thread this week about the single best investment you can make with your generator, the Micro Air EasyStart

50a service on a RV is kind of stupid in most cases. It was to solve the need that some RV’s were coming with two air conditioners. The reality is the industry simply force the AC units to be more efficient then we would’t need 50a service. Remember 50a is really 100a @120v split across two legs. Ultimately the rig has 100a coming into it from two different legs.

So if you have one AC the starting amps will be like 17-18a for most AC’s. That is just for a brief period, then it will settle down around 12-13a. The problem is traditionally is you needed to size the generator for the largest draw which would be the AC. This is why smaller units were partially setup to parallel and why inverter generators became popular (not to mention noise and efficiency).

My point is you don’t need a big honkin generator. If you wisely setup your trailer with a say 2kva generator and Easy Start you will be able to run just about everything. I have the easy start installed on both AC’s on my trailer.

Now running both at the same time requires me to run 2 x 2kva generators. However, if we plan properly normally we don’t need to run them both all day so it is not a problem.

+1 :point_up::point_up_2:

Plus it pisses everyone else off around you!

Seem to me that you can only use the AC if you are on one AC. 2000 watts is only about 17 amps. Googling it seems AC uses about 12-16 amps so you are left with very little wiggle room for say fridge or laptop.

Really it makes way more sense to have a 3000 watt generator. They seem to be some of the most popular to me at events and dry camping spots.