Blondie, you mentioned you'll have three small regulators. Those are charge controllers, however, it's not the best way to go in my opinion. I'd much rather have a single controller instead, and if at all possible, an "MPPT" type controller. They cost more, but the price is offset by getting all the watts possible out of your solar panels. A cheap shunt/switching controller will only get about 75% of the rated watts out of your solar panels. So you loose 142 watts in your three 190 watt array with a cheap switching controller. At $2/watt, that's basically $284 thrown away, which could be put into the cost of a MPPT controller over a cheap controller.
The challenge to answer is how big a controller you require, and that depends on whether you'll be expanding the system in the future. As a system grows, the lower volt systems will become unruly, as bigger controllers are required, heavier cables needed, efficiency losses increase. This is why you'll see systems of 24v, 48v, etc. With your three panels, and batteries wired for 12 volts, you'll be generating 47.5 amps, so you'll need a controller of at least 50 amps capacity. If you wanted to add more panels, you'd have to either operate at a higher battery voltage (which means replacing power inverters with ones of the new system voltage) or add another charge controller. Fortunately, many controllers now-a-days are set up to be adjustable between different bank voltages, so as your solar array increases in size, you can continue using the same amperage limited controller by increasing battery bank voltage. (reducing amperage)
Confused yet? I'll keep it simple.
Option #1: Use the "regulators" supplied. $0 additional cost, least efficient.
Option #2: Buy a 60 amp PWM controller (Morningstar TriStar TS-60 for example) $200 & more efficient
Option #3: Buy a 60 amp MPPT controller (Morningstar TriStar MPPT 60 for example) $475 & most efficient
BTW, I'm not pushing Morningstar. It was just one example. Outback, Appollo, Xantrex, etc are all fine choices.
As far as my cabin, still a long ways off. However, weather permitting, I believe I'll be installing my septic the second week of October. Fingers (and toes, legs, arms, and eyes) crossed the weather will play nice.
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