Sizing batteries and inverter to run a pet cool a/c

[windmillnut]

My wife Deirdre likes the idea of a teardrop trailer. The three things she requires however is that it have a/c, that it be safe and that it look good.

The last two requirements prevent me from building it myself. It has been over a year now and we are still designing. We started big and are cutting things down to what we really need. A/C is a need because Deirdre gets cranky when she is hot.

To the question. A petcool will be mounted on the tougue of the trailer with hoses going into the cabin. A friend who works in HVAC is going to rig me a thermostat so we do not have to adjust the temp manually. I would like some help on sizing the inverter/charger and the batteries to run the petcool.

The batteries will be charged from the shore power hookup as well as from the tow vehicle. We would like to be able to spend two days in a spot without power before having to check into an improved campsite or run the tow vehicle to charge the batteries.

We are thinking that two of these would do, but do no know how long exactly they would power the a/c or how long it would take to recharge when they became drained say to 50%.

http://www.trojan-battery.com/Products/ ... ame=4D-AGM

We are also thinging of a Xantrex 2000W Inverter/Charger.

We have decided that this is the make or break part of the trailer so we feel it would be better to have extra capacity instead of not enough.

Thanks,
Brian

[madjack]

Brian...you may wanna rethink the battery thing...the PetCool uses 3.4 A @ 120vac...there is a 10 fold conversion rate when going to 12vdc or 34AMPS needed

...the batteries you linked to are monsters...115#s apiece with 165AH of usable power(to 50%)...that works out to just 5 hours...assuming that the AC would run only half the time, you are still looking at only 10 hours of usage or about overnight on 100% charged batteries (not counting the power loss due to inefficiencies in the inverter)

...charging... you will need to input 165a back into the batteries to replace what you used...so a 10a charger would take 16+ hours

a much better solution would be to get a "camping" generator of 1000 to 3000 watts...this would cost you between 600-1000 bucks...the little camping generators such as those by KIPOR(recommended) or HONDA...they are very quiet(about conversation level)....or just stay where there is shore power available...
madjack

[Sonetpro]

Brian,
I was thinking the same thing. I don't want to bust your bubble, But it won't work.
I also have a 2000 xanatrex and I used 2 4D 125 amp battery's and tried it out. It ran it fine but the amp draw was too much to be comfortable with. I put a amp clamp on it and experimented. When it started out it was pulling 34 amps. The trouble is as the battery voltage drops the current increases. after only 10 minutes the amp draw was 37 and after 30 minutes it was over 40. At that point I realized that it wasn't going to work.
As MJ has suggested I bought a Kipor and it works great. It is very quiet.

As for the battery, I highly recommend it. They are a lot of $$ but worth it. I have 1 in my tear and it will last all weekend. They are designed for deep discharge without harming the battery and they have a 12 year service life. We use them at work and some are still good after almost 20 years of service.

Don't worry about taking a year to design it. It took me 6 month to get my design where I was happy with it.


Running the AC on the beach.

[windmillnut]

Madjack and Steve,

Thanks for the information. The Kipor route is the way we will go. Steve if you had to do it again would you buy a smaller inverter and smaller batteries knowing that you would not use them to power the a/c?

Thanks
Brian

[madjack]

Brian, what else will you be running on off the inverter...a TV, microwave(use the KIPOR)...a few 12v lights, a 12v fan and a 120v TV/DVD will run an easy 3 days on a regular WalMart group 24/27 deep cycle battery...use as small in inveter as you can since the larger you are the more inefficient it will be.....
madjack