With PV solar panels a solar charge controller is often used to prevent the batteries from being over-charged. Unfortunately a solar charge controller cannot be used with a wind turbine generator since the wind turbine controller must also ensure that the wind turbine to which it is connected is constantly under load to prevent it from spinning out of control (overspeeding) and being damaged in strong winds.
Wind Turbine Charge Controller
A typical wind turbine charge controller constantly monitors the battery voltage. If that voltage approaches a user set maximum (the battery bank float voltage) then the controller turns on a dump load (aka shunt) for example an immersion heater element, electric heater, or car headlight bulbs, to dissipate any excess power to prevent it from over-charging the batteries.
Buy a Wind Turbine Charge Controller
ebay UK seller off_grid has been selling a great range of wind turbine charge controllers for the last seven or eight years, including one three phase AC controller (pictured above) with a built in three phase bridge rectifier (see the six low voltage drop Schottky diodes with heatsinks on the right side of the image), and one DC controller (pictured below) which can take in DC inputs straight from Ametek DC motors and treadmill motors etc, often used as wind turbine generators.
These wind turbine regulators are rated with current handling capacities of 23 Amps and can be configured for either 12V or 24V charging. The battery float voltage can be manually set to 13.2V-15.2V (12V charging) and 26.4V-30.4V (24V charging).
A switched output is provided on the DC controller which can be used to power a dump load cooling fan. This switched output turns on when the dump load is switched on, and remains on for almost a minute after the dump load is switched off in order to cool the dump load down.
High current rated solid state MOSFETs are used (rather than relays) which makes these regulators robust and reliable.
LEDs are used to indicate the current charging status – green LED on when batteries are fully charged and the dump load is on; red LED on when batteries are ready to accept charge.
These regulators can be configured in one of two different ways as illustrated above with the DC version – either as a simple battery shunt Dump Load, or in Diversion mode. When configured as a battery shunt, the dump load is powered directly from the battery thereby bringing down the battery’s level of stored charge and preventing it being overcharged. When configured in diversion mode, the dump load is powered only by the instantaneous power generated by the generator – i.e. the battery retains whatever charge it holds, but all power from the generator is diverted to the dump load.
Both the AC and DC regulators sell for approximately £ 30+. Click here to find out more or to buy now: AC and DC Wind Turbine Controllers.