Battery powered rooftop AC installed in my sleeper.

It is 96 degrees in Kansas City this afternoon and the A/C in the sleeper is set at 68 and doing a great job. I bought a Dometic RTX2000 DC powered rooftop unit, (2) 200 amp hour AGM batteries, a Victron Orion 30 amp DC/DC charger plus a few smaller items like a battery cut off switch, some 6 gauge wire and a few fuses. I’m all in for just over $3800. I never have to buy gasoline for a generator, never have to remember to plug in a battery pack and never have to pay to service an APU. It is self charging off the truck alternator (standard 160 amp Paccar) and will fully recharge after 5 hours drive time if I run the unit 10 for hours. Keep in mind this is installed on a Pete 579 so I have a flat roof. They do make another version of this unit that will mount on the back wall although I do not have the model # handy. You will need to cut a hole for both versions.

Here are some details with pics to follow. The RTX2000 runs on 12 volt battery power. It weighs 72 lbs and the fiberglass roof on my Pete handles the weight no problem. It is rated at 6824 BTU and draws 58 amps at full power and 10 amps on eco-mode. I estimated 1 hour of full power to cool the truck down if needed and 9 hours on eco mode to hold the temp through the night. That would equate to 148 amp hours of battery usage. It was recommended to have double the battery power that you intend to use so you never draw down your batteries below 50% of their capacity. This is why I chose to use 2 200 amp hour Renogy Deep Cycle AGM batteries for my power. They are heavy @127lbs each but much cheaper than equivalent Lithium batteries. They fit nicely under the bunk.

Charging: I chose the DC-DC 30 amp Victron Orion-Tr Smart charger to handle the hard part. A DC-DC charger draws power from your trucks battery bank. It will draw the 13-14 volts off the batteries only when the engine is running so your alternator will still only be charging the truck batteries but there will be a constant draw to the charger until the auxiliary batteries are fully charged. This is a bluetooth unit so you can monitor the charge status as you go down the road, a very nice feature to make sure you are ready for another hot night. I did make a few phone calls to verify the that the stock 160 amp alternator would be sufficient to charge the auxiliary battery pack. The Victron charger also has a built in isolator so it cannot draw off the truck batteries when the engine is off. I also added a cut off switch between the truck batteries and the Victron charger in case I need to service any of the components.

A few other install notes. I remover the factory pretend insulation and installed a 2” wool based insulation I found at Menards to keep the cool air in. It took me 1.5 days to remove the inner panels, install the unit and insulate the sleeper. I took me another 1.5 days to do all the wiring and electronics. The only time I needed help was to put the unit it the hole without mucking up the seal and caulk on the roof. Other than that it wasn’t too bad at all.

 

Here are pics of the unit going in.

 

Insulating the sleeper

 

The Renogy batteries in a home built box, the Victron charger with cut off switch and fuse.

 

No reason other than it looked like it would work. It is 2”x24 which worked perfectly between the structural supports in the roof and walls.