Solar Questions
I'm interested in adding solar power and lithium batteries to our trailer, but I'm getting lost in the weeds. For starters I calculated what I think would be our worst case power need (without u...
Forum Discussion
BeerBrewer wrote:
Unfortunately the amps that I used for each appliance came from the electrical load rating table in the manual for the trailer. I estimated the number of hours of use for each. For instance the manual claims the Frig uses 3 amps of DC power and 6 amps of AC. I assumed that when using propane there is no AC usage, but I was stuck with the DC. Since the frig runs for 24 hours per day that equated to 72 amp-hours and yet others have said that it uses only 17 to 20 amp-hours. So I TOTALLY agree with you that my numbers look high, but unfortunately I've got nothing else to go on. If you folks have more realistic numbers I'd appreciate it.
You numbers aren't that crazy. Your WH figure can come down, also the pump--you will run out of water pumping that much--take Navy showers.
Your 180AH minus ( fridge 72-17) 55 is 125 and minus 48 furnace is 77AH, which is like the 75 we use approx. Furnace is extra and it depends on ambients and rig insulation, etc.
Two 6s at 230AH down to 50% is 115 and you want 160 for two days of no furnace camping between generator recharging two hours( a 50-90 = 40% = 92AH) so you need an extra 45AH/2 = 22.5AH from solar daily to do that or else gen charge every day
To do a 50-90 in two hours on 230AH you need a 75 amp charger and a 2200W inverter gen to run it.
So it's Friday and off you go on a sunny weekend off-grid. You need to do a 50-90 on Sunday and Tuesday unless you go home on Tuesday and plug in for a full battery recovery.
Add some furnace time and you can do some gen time every day instead of every second day. You can get more battery bank if you decide to camp in the winter so you can run the furnace at 100AH a day.
If you do camp in the winter off-grid, expect hardly any solar, so it is all up to generator recharging. You can still do 50-90s every second day if you have more of a battery bank and charge for a longer time each session if it is not too cold out. Four 6s would be good.
Another thing is that 230AH is 15% less at 32F, so your bank is 195 now, and a 50-90 is only 78AH. So you need those four 6s instead of two for sure. Two for the normal 77AH and the other two for the furnace, and a 50-90 every day.
(Which is why you can camp in February and have the whole Provincial/State park almost to yourself :) )
