The 2016 Axis we bought isn't prewired.
The first thing that you need to do is an energy audit. This is a bit of a pain but is very important. There are several spread sheets on the internet that will give you a ball park idea.
The energy will determine battery bank size. From this you determine the amount of solar.
Review this link
RV Electrical
also this one for an introduction to 12 volt
The 12volt Side of Life (Part 1), his SOC table is incorrect for most 12 volt lead acid batteries.
See here for SOC
http://http://batteryuniversity.com/...tate_of_charge and other important battery facts.
Don't expect to run things like the A/C, MW, drip coffee maker, or hair dryer.
Currently we have two 100 watt panels in a portable configuration.
25 feet of marine grade 8 AWG wire between the panels and the charge controller, CC. It covers our conservative needs barely; lights and 12 volt fans.
The batteries that came with our Axis are unknowns, possibly a cheap Exide, not on a par with Exide's normal deep cycle batteries.
Here is some math to think on.
WH usage based on battery bank
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· 210 AH * 12 volt * 0.85 AC inverter eff * 1/1 days storage * 0.50 maximum discharge = 1071 WH per day (RV/Boat)
· 210 AH * 12 volt * 0.85 AC inverter eff * 1/2 days storage * 0.50 maximum discharge = 535 WH per day (off grid cabin)
· 210 AH * 12 volt * 0.85 AC inverter eff * 1/3 days storage * 0.50 maximum discharge = 357 WH per day
Charging wise--Two ways to calculate the solar array size. First, is based on a 5% to 13% typical rate of charge. 5% is OK for weekend/seasonal use, 10% or above is recommended for full time off grid charging (and if you have "significant" day time inverter/battery loads:
· 210 AH * 14.5 volts charging * 1/0.77 panel+charge controller derating * 0.05 rate of charge = 198 Watt array minimum
· 210 AH * 14.5 volts charging * 1/0.77 panel+charge controller derating * 0.10 rate of charge = 395 Watt array nominal
· 210 AH * 14.5 volts charging * 1/0.77 panel+charge controller derating * 0.13 rate of charge = 514 Watt array "cost effective" maximum
These numbers are based on two 12 Exide Stowaway batteries for the Ah and the rest comes from the solar-electric.com forums.
A pair of American made 150 watt panels on Ebay are $330.
Use a major brand of CC such as Morningstar or Bluesky.
Midnight Solar 150 Vdc breakers can be found on the solar-electric.com sales and run about $11 a piece. You can also get a breaker box with din rail mounting for the breakers from them. These folks are Northern Az Wind and Sun and my personal dealings with them have been good. They also have solar panels and mounting systems but are expensive.
Donot use in line glass fuses for the solar system they will fail. Breakers are best.
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