Battery Isolator

[Capt.Chuck]

I have an 91 amp alternator and wind generator. One house bank 420 amps, starting battery gets trickle charged off the house battery. Should I use a Battery Isolator to help control the alternator and wind generator output? The second battery connection would go to a 12 water heater element.
Thanks for your input,

[Andina Marie]

No, an isolator is the wrong choice. Isolators divert current to the LOWEST load so it will always be sending power to the water heater even if your batteries need a charge.

The regulator on the alternator will cut the current down as the batteries reach full charge so you don't normally want to be wasting fuel to heat water at such low efficiency. If you NEED extra water heating look into a heat exchanger process.

The wind generator output is free (more or less) and although I can't name a source I understand there are regulators that already have a "dump" output to connect to a resistive load like a water heater. This will only divert energy to the heater AFTER the battery has been charged.

[Capt.Chuck]

Thanks, that's right. What was I thinking

[Kettlewell]

In my experience, the simplest and best way is to direct all charging sources, including the wind and alternator, to the house battery bank. If you also want hot water run the cooling water">engine cooling water through the hot water heater, as many boats come standard. I prefer to just stop the wind generator if it is producing excess power--why leave it spinning and wearing out bearings and such?