bka0721 wrote:
DiploStrat wrote:
Steve,
-- A large enough battery bank to run an air conditioner. (The American south is soggy. :))
We take delivery this month and will begin to collect some real world data. Keep yer fingers crossed!
You're not seriously planning on running an Air Conditioner off of a battery bank? I can run one off my battery bank, for a short period of time (as witnessed by one of the TC Moderators), but have you put pencil to paper and determined how big a bank of batteries you will need to run one, for say 2 to 4 hours? After you do that, how do you plan on bringing the S.O.C. back up? If you say, solar panels, where are you going to mount them and store them? If you say you will charge them up by shore power, why not use shore power to begin with, or alternator how long will you run your engine? I am not doubting you, I am just curious in how you plan to solve this issue.
b
Long/short answer(s) ;)
Actually, I have spent a lot of time with a pencil on this and the results are in the design of Ndeke Luka. Sadly, it is now too late in the year to see if I got the answer right. :( But it goes like this:
-- Small camper, under 100 cubic feet.
-- Small air conditioner, around 5k BTU.
-- Big insulation on all four sides and dual pane windows.
-- Double roof (solar panels).
-- 600Ah battery bank = 300Ah usable
-- 500w solar.
-- 250A alternator with over 150A charge rate to the batteries.
-- 2800w inverter/charger to handle air conditioner starting loads. (With transfer switch and 100A charge rate.)
If all goes well, this gives grossly two days of autonomy at 150Ah per day.
If the air conditioner draws 10Ah, then you have five to ten hours.
At 150Ah charge from the alternator, then a recharge should work out to about two hours of bulk charge.
500w of solar should harvest about 100Ah per day.
Real world numbers? Sorry, not yet. Earthroamer and Roadtrek claim numbers like these; I will simply have to wait for next summer.
However, there is nothing in my design that precludes simply opening a window and turning on the Fantastic Fan if all my numbers are wrong. (And I do have a shore power cable for use in the U.S.!) :W
Hope this is helpful.