ONAN Generator or more batteries


Active Member
We have a 2015 Bighorn 3570RS that i ordered with the factory generator prep package (wasn't sure if i would use it or not at the time, playing it safe) I know at the factory they normally would install (if ordered) the Onan RV QG 5500 LP which is a 5500 watt generator. I do not want the added 279lbs generator weight nor feel for my requirements i need anything near that capacity.
I was thinking instead of getting an Onan RV QG 2500 LP which is rated at 2500 watts and only weighs 125lbs.
We mainly want it to permit a few overnight stops at dry camp locations (walmart, flying j, etc.) when on the long haul. I need it to power my residential fridge, furnace on cold nights when hauling from Ontario Canada to Arizona. I thought about instead switching to four 6 volt batteries in place of adding a generator but am worried that after one overnight stop and depleting the batteries a fair amount from running the fridge and furnace overnight, that my 2015 F350 would not be able to both keep the fridge running plus charge the batteries sufficiently during the next 9 hour or so haul enabling a 2nd or possibly 3rd overnight stop. I considered solar but feel it may not be reliable enough with hauling in the winter months (clouds, snowing, etc). I have a couple of questions:
1. Does anyone know if the Onan RV QG 2500 LP will hook up to the Heartland gen prep package and provide all the features (remote power on, monitoring, or anything else i might not know about that the Rv OG 5500 would provide (short of more power). Experiences with the RV OG 2500LP?. Again i don't plan on and never will be doing any lengthy dry camping stays but we do love the comfort of knowing when it starts getting late we can pull over somewhere and were good for the night (summer or winter). Many will say cheaper to simply pay at a campground but that takes advance booking (due to size of rig, wanting a pull thru spot, and to ensure a vacancy), possible late night arrivals, sometimes requires traveling too far off the route on roads i would prefer to avoid, and finally most are closed in the winter months).
2. What are the thoughts of four trojan 6 volts instead of the generator and the likelihood i could do multiple one night stopovers across the country with both furnace and residential fridge running at night as long as i have 9 hours of drive time between each stop (would the batteries have time to recharge during the hauls or will i end up freezing my ___ off with the furnace and fridge shutting down half way thru the night during the 2nd or 3rd nights stop)?
Last edited:


Well-known member
Hi rpotter,

I haven't heard of anyone installing an Onan 2500. But if it runs on propane, you should be able to hook it up to the propane feed. The output of the genny goes to a junction box that is connected to the transfer switch, so that shouldn't be a problem.

If the exhaust is configured the same as a 5500, that shouldn't be a problem either. But unless someone has gone before you, you'll be blazing a trail for everyone else.

20 amp service is not a lot. It might not be a sure thing to be able to run an air conditioner. The residential refrigerator may draw something like 8 amps when the compressor starts, and the power converter can draw more than a few amps. But if you don't need air conditioning, you might be ok.

On the batteries, keep in mind that the charge from the tow vehicle is slow as the wiring is not going to carry a lot of amperage. Not sure you could keep them fully charged day after day without plugging into shore power.