Wiring diagram review

As far as I can tell, the fusing looks OK.

For the battery bank, take a look at these diagrams for wiring your battery bank. Your drawing does not "balance current" flow between the two batteries as well as you would like (the battery next to the leads that go to the fuse block will cycle more current than the battery farther away):

http://smartgauge.co.uk/batt_con.html

And a question about your overall design and expectations... You have a relatively large AC inverter, a smallish to medium size battery bank, and a single (?) smallish solar panel.

I like to call the battery bank the "heart" of your system--And design everything around it (loads, charging). A 200 AH @ 12 volt battery bank should have 5% to 13%-20% rate of charge. 5% can work for weekend/sunny weather usage. 10%+ is better for full time off grid usage:

• 200 AH * 14.5 volts charging * 1/0.77 panel+controller losses * 0.05 rate of charge = 188 Watt array minimum
• 200 AH * 14.5 volts charging * 1/0.77 panel+controller losses * 0.10 rate of charge = 377 Watt array nominal
• 200 AH * 14.5 volts charging * 1/0.77 panel+controller losses * 0.13 rate of charge = 490 Watt array "typical cost effective" maximum

And then there is sizing the array for your loads... Which is the rate of energy usage (Watt or AH @ 12 volts) times Hours of usage per day/night. For a battery bank, we generally assume 1-3 days of "no-sun" (cloudy weather) and 50% maximum discharge. For a cabin/home, typically 2 days and 50% discharge is optimum (all things considered). For an RV with minimum space and weight, assuming 1 day of storage and 50% maximum discharge is sometimes used (more genset usage, or simply cut back on energy usage during bad weather)... And knowing where/when you will be dry camping (US southwest in summer vs Canadian border in winter).

Based on your battery capacity and a 1 day+50% capacity, the estimated daily energy usage (maximum suggested) would be around:

• 200 AH * 12 volts * 0.85 AC inverter eff * 1/1 day storage * 0.50 max discharge = 1,020 Watt*Hours of daily usage
• 200 AH * 1/1 day * 0.50 max discharge = 100 AH @ 12 volts (if you prefer to work in AH)

Then the amount of sun. Let us guess that you camp around Pittsburgh PA, fixed array, mounted flat to your RV roof:
http://solarelectricityhandbook.com/solar-irradiance.html

Pittsburgh
Average Solar Insolation figures

Measured in kWh/m2/day onto a horizontal surface:

Jan	Feb	Mar	Apr	May	Jun
1.77	2.49	3.37	4.48	4.98	5.63
Jul	Aug	Sep	Oct	Nov	Dec
5.59	4.96	4.12	3.05	1.84	1.48

Note, if winter camping, you really need to tilt the solar array to a 45 degree angle or more. Anyway, "hours of sun per day", if you are camping in "sunnier" weather/seasons, around April thru September or a minimum (long term 20 year average) of 4.12 Hours of sun per day. Your 100 Watt panel would supply, and a 377 Watt panel would supply:

• 100 Watt * 0.52 off grid system eff * 4.12 hour of sun (ave September) = 214 WH per day (Sept)
• 377 Watt array * 0.52 off grid system eff * 4.12 hours of sun (Sept) = 808 WH per day (Sept with 10% rate of charge array)

AC inverters--Easy to buy a big one but difficult to supply a "worth while" amount of energy per day from a small solar system/battery bank.

Your AC inverter running at 500 Watts would use 50% of your battery capacity in about 2 hours (500 Watts * 2 hours = 1,000 WH). And would take about 5 days to recharge with your present 100 Watt panel/solar array in September (214 WH * 5 days = 1,070 WH average harvest).

Also, AC inverters take power "just turned on"... Smaller ones take around 6 Watts (tare energy usage) vs 20-40+ Watts for larger units (and inefficient units). With a small system, you have to take the AC inverter Tare losses into account (do you have a power switch somewhere to turn off the AC inverter when not needed?). For example, if your inverter took 10 Watts Tare and you left it on 24 hours per day:

• 10 Watts * 24 hours = 240 WH per day

Or more energy than your panel can harvest in September every day.

Also, battery banks have a maximum output current that they can support. AGM batteries do have a higher output current capacity (in theory, your AGM batteries could support ~C/1 discharge rate--Or fully discharge 200 AH in 1 hour). However, you have to decide if that is the load profile you want/need... Do you want to run your AC inverter at 100% power for less than 1 hour and take 5-10 days to recharge... Or do you have something that draws a large amount of current for a short period of time (like a skill saw) and most of the time, the tool is turned off...

For FLA (flooded cell lead acid deep cycle storage batteries) and not a bad idea for a "balanced" AGM design... For a 12 volt system suggest around 125 to 250 Watts AC inverter per 100 AH of 12 volt battery capacity:

• 200 AH (at 12 volts) * 125 Watts / 100 AH = 250 Watt AC inverter maximum "nominal" recommendation
• 200 AH (at 12 volts) * 250 Watts / 100 AH = 500 Watt AC inverter maximum "maximum" suggested

Since you have AGM batteries, you could support your 1,000 Watt AC inverter--But you can drain your battery bank very quickly.

I will stop here. I have made lots of guesses as to your location and energy needs and camping habits. I could easily be more wrong than right--But the math and background information is there for you to see how the calculations are made and what assumptions we need to design a "balanced" off grid solar system.

Questions, corrections?

-Bill