I picked up a pair of 'no name' VSRs at a 4 wheel
shop that are designed to charge a domestic battery
when the 4wd is running. They are nominal 30 amps at 13.8 volt. They have a screwdriver adjustment to set the activation voltage and I simply set it to the maximum. Instead of a second battery
I simply attached a 300 watt wire wound resistor designed to be a dump load (try ebay or any wind generator retailer as they are a common item) which simply make heat. I have 2 of these setups.
My logic is that it is the 1000ah of flooded cells in the house bank can take a big charge without damage and that in fact periods of gentle bubbling are just unplanned equalization
. In the event that this bubbling starts to get too vigorous and the voltage rises to 15volts the VSRs kick in and burn off the surplus power until the voltage drops. I have an alarm
across the dump loads to alert me to surplus power or a problem.
I probably use a little more battery water
but battery life seems unaffected at about ten years.
To state the obvious, this approach would be damaging for other types of battery chemistries and definitely not approved or recommended by anyone!
The big advantage is that I seem to get a lot more power into the batteries as the regulators are often too quick to kick in. Secondly, on more than one occasion the device has 'saved' the batteries when a solar panel regulator failed on and the engine alternator
However, your comments about 80 percent reduction in power suggest to me an electrical
problem. The d400 manufacturer has a useful troubleshooting guide which may help. see Micro Wind Turbines manufactured by Eclectic Energy Ltd | D400 Wind Generator
I see you're in Pittwater ... what a wonderful part of the world. I have spent 1000's of hours mucking around in boats there and the rest I wasted. We are in Northern Europe
and slowly seeing Spring emerge.
Hope the comments help.