Help on Using a 12v AC system...

[hammersley]

I'm looking at a pickup "camper" that has the option of using an inexpensive window AC (home unit) - and venting it outside... . and running it entirly on 3 HD 12 v batteries. There are a lot of manufactures - such as this one... . Now the Camper Dealer is building a cabinet for this to run in..... some questions... .



1. It uses 5. 5 amps when running on 120..... when she runs through a converter what is the draw?????



2. I have a blank sheet of paper so I can install a bunch of batteries... . What batteries would you use and what would be the run time for say 3 or 4 ?? Now I realize that the AC won't run all the time... ...



3. Please explain the advantage of using a 6 volt battery?





AFS60NX Energy Star 6,000 BTU Window A/C



115 Volts / 60 Hz / 1758 Watts / 5. 5 Amps

 

[SBall]

A 5. 5 amp load running on 120 volts represents a load of 660 watts. Ignoring losses, this load when asked to run on 12 volts would suck 55 amps! You would need one hefty inverter and some really heavy gauge wire, and maybe an old U-boat battery. But something doesn't add up... The nameplate data "115 volts/1758 watts/5. 5 amps" is confusing.
As for batteries, If your (55 amp) air conditioner ran at 50% duty cycle for 8 hours, your total power requirement at 12 volts might work out to 220 amp-hours. In theory, 4 good 6-volt golf cart batteries might provide the required power with some reserve. However the wiring, fusing, and inverter configuration would still be the issue. Cost as well! I'd say use a fan instead.

 

[Hoefler]

"The nameplate data "115 volts/1758 watts/5. 5 amps" is confusing. "



The reason for the 1758 watts rating is for the start up load of the compressor. That equates to a 16 amp draw on 110 volts, a 146. 5 amp draw 12 volt. You would need some hefty deep cycle batteries to handle it. You also need to consider the heat factor that the inverter will produce and the ventilation needed for the batteries. Also, to charge your batteries, it will take a long time with a good charger. If you plan on using your truck's alternator, you could burn it up. All in all, a 2500 watt generator would be cheaper. I have a Coleman that is very quite and is rated for 3,000 watt.

 

[AClayton]

"The nameplate data "115 volts/1758 watts/5. 5 amps" is confusing. "



The reason for the 1758 watts rating is for the start up load of the compressor. That equates to a 16 amp draw on 110 volts, a 146. 5 amp draw 12 volt. You would need some hefty deep cycle batteries to handle it. You also need to consider the heat factor that the inverter will produce and the ventilation needed for the batteries. Also, to charge your batteries, it will take a long time with a good charger. If you plan on using your truck's alternator, you could burn it up. All in all, a 2500 watt generator would be cheaper. I have a Coleman that is very quite and is rated for 3,000 watt.

I second everything in this post. Better off w/Genset! An inverter of at least 2500 watts would be required to start an A/C unit of that size plus be able to withstand the heat generated from the load.



Alan