I have often thought that it would be nice to have a short break in a journey...lunch, nap, etc. and do it with the comfort of Air Conditioning. I carry a Honda 2000i generator in the truck bed, but the effort of starting it and attaching the cable just seems to be too much effort for a short stop. Call me lazy. So I have been researching means by which I can run my AC on batteries for short periods. I'm not talking hours...just a short time to have that refreshing break.
The challenge with AC on battery is something called Locked Rotor Amps. This is that instantaneous burst of energy required to get your AC compressor turning. In my case the Atwood Air Command 13.5 has a LRA of 63.5. You may consult your owners manual for your specific LRA. The running amps are only 12.5 for mine. (That's high based on actual experience) My quandary was that I could run the AC with my Honda 2000i, but when I wired the AC into the 2000 WATT inverter the compressor would not start. So began my quest for the holy grail...running my AC on batteries.
Solution:
Install an "Easy Start" soft start kit by Micro Air which reduces the LRA draw by as much as 75%. https://id144248.webhosting.optonline.net/microair.net/merchantmanager/product_info.php?cPath=4&products_id=4
Install a Kisae transfer switch so the inverter knows when there is no shore power. http://www.donrowe.com/KISAE-TS20A-Automatic-Transfer-Switch-p/ts20a.htm
With some consulting by Steve L (ScubaRX) I finished the project today at 4:00 PM. With breath held I unplugged from shore power. turned the inverter on, and cranked the AC thermostat down to 80 degrees. The heat index was about 90 at that time. To my utter delight the AC cycled on just as it was supposed to. I was so excited I called Steve to share the good news and we chatted for about thirty minutes while I performed some battery checks. With solar on the draw was 0.7 Amps...not bad for the comfort of AC. Steve suggested I turn solar off to see what the actual draw would be. I was pleased to not that only 4.5 -5.5 amps were being used while the AC was on battery.
Now before you get all exercised about ruining my batteries remember that this is a short term thing. One, maybe two hours while at a rest stop, or to leave our Penny Lane in a cool trailer while we have a meal in a restaurant.
The important thing is that it can be done. Not cheaply at about $400 total...but well worth it for me.