#SEA50 in waterproof potted case is only $1339.95 plus $14.95 S&H -
 
New Generation SEA50 Technology With New Charge Characteristics
 
The #SEA50 charge controller is recommended for all applications where
keeping a reserve of battery power is important. Keeps your batteries topped off.
 
Model #SEA50
 
Cycle Characteristics:
12 Volt Bank - Turns on and starts dumping power at 14 volts. Turns off at 12.5 volts (+ - 7%)
24 Volt Bank - Turns on and starts dumping power at 28 volts. Turns off at 25 volts (+ - 7%)
48 Volt Bank - Turns on and starts dumping power at 56 volts. Turns off at 50 volts (+ - 7%)
 
The +or- 7% variance is caused by differences in diversion load size verses battery bank size.
Many factors can come into play depending on your systems size, load and the age of the batteries.
 
Novice notes:
A fully charged 12 volt battery is 15.1 + volts and not 12 volts
A fully charged 24 volt battery is 30.2 + volts and not 24 volts
A fully charged 48 volt battery is 60.4 + volts and not 48 volts
 

NOTE: The SEA50 internal relay (black wires) can also turn on and

off 120 volt AC appliances up to 15 amps since it is an isolated circuit.

 
TWEAKING THE SEA50 FOR HIGHER CHARGING RANGES - If you want your batteries to cycle at higher voltage levels you can put
a 10 to 100 ohm / one watt resistor in line with the green sensor wire and trick the SEA50 into higher voltage / charging ranges. This may
take a little experimentation to choose the right resistor to get the cycle style you need but it is an effective and simple way to make the
SEA50 do versatile jobs. These are common Radio-Shack® parts.
Ohm's Law Calculator