Join Date: Apr 2014
Location: Bozeman, Montana
Mentioned: 8 Post(s)
Tagged: 1 Thread(s)
Quoted: 325 Post(s)
Thanked 566 Times in 382 Posts
Couple of thoughts...
For the 12 volt DC panel, one of the loads you have listed is a 12 volt water heater. Unless this is a very low wattage water heater, its probably going to need to be wired directly to the battery via its own breaker.
For the fuse for the whole DC panel, add up all the loads that could possibly be on at one time plus a bit more for future loads and that gives you rough fuse/breaker size -- I use 60 amps.
For the wire size and fuse size for the inverter/charger, the best thing to do is look in the manual -- they should have details on what size wires they want for various lengths. Should be at least (2800 watts/12volts * 0.9 ) = 260 amps, but, go by what the manual says.
There will be a limit to how long you can run the AC from the battery. I think your AC draws about 1200 watts, and the draw from the battery when its running will be about (1200 watts/12 volts * 0.9) =
111 amps (where 0.9 is inverter efficiency). I guess you have 400 amp-hrs of battery, and if you are OK with running them down to 20% state of charge, this gives you 320 useable amp-hrs, or just short of 3 hours of operation. Since the AC probably won't be running all the time, you would probably get more than this, but you have other loads beyond the AC, so this would cut the time some. The smaller you can make the area that you air conditioning the better.
For the shore power wire, you might want to consider using a 30 amp plug and cable. The 30 amp receptacle is available in most shore power pedistals, and if its not available, you can carry an adapter to plug the 30 amp plug into the 15/20 amp receptacle on the shore power pedestal. With the AC, you have some fairly large AC loads, so the extra capacity of the 30 amp cable might come in handy?
That Bluesea ML-ACR is quite a gadget. My first thought was that it was a whole lot of money for a battery isolator, but it does have a lot of nice features that others don't.
The best way to pick the fuse sizes for the van battery to house battery wire would be to ask Renology what they recommend for the maximum charging rate for the two batteries, and size the fuse to that or just a bit more. If you can't get a number out of them, then I think 100 amps would be in the ballpark -- that charging at 0.2C plus some margin. Maybe others with AGM batteries have a better number?