Need help on wind turbine output

anhldanhld Registered Users Posts: 1

Dear experts,

I am making my own wind turbine (30W). I used a DC motor which connects directly to turbine shape. The motor is 310VDC - 750rmp - 22W.
I want to connect the battery blank to turbine and use with LED 12V.
I would like to ask for advices:
1. Do I need the wind generator controller before connect to the battery blank since the wind generator controller is for 3-phase AC motor?
2. As the output voltage of DC motor increases with the turbine rotation, how can I control the output voltage around 12V for charging the battery?

Thank you,


  • BB.BB. Super Moderators, Administrators Posts: 31,690 admin
    Welcome to the forum Anhld,

    Questions like this are always a bit difficult to answer.... I know a fair bit about motors, but not much about use in wind turbines.

    But, taking some basic information, I am not sure that this motor will work well for you.

    First, a 22 Watt @ 310 Volts indicates the actual rated current it around:
    • 22 Watts / 310 Watts = 0.071 Amps
    At a charging voltage of ~14.75 Volts (typical flooded cell lead acid battery):
    • 0.071 Amps * 14.75 Volts = 1.05 Watts
    Which is nowhere near the charging power you are looking for. Generally motors/alternators/generators are designed for a maximum operational current. To take a 310 Volt motor and drive a 12 volt battery bank--Your alternator's output current will be 0.07 amps @ 310 or 12 volts...

    More or less, the output voltage varies with RPM. Yes, you can get more current at higher rpm--But you will have limits (overheating of the coils--Power = Current^2 * Resistance).

    Generally, you would connect a 3 phase rectifier (6 diodes) to change it to DC output. And connect that directly to your battery bank.

    And, use a dump controller that, when the battery is full, the dump controller "turns on" and generally the output goes to a power resistor to keep the battery from over charging).

    We do not do much for Do It Yourself wind power--You may find more help/information in this links: (good forum for DIY Wind Power)
    Hugh Piggott - Scoraig Wind Electric site for tons of info (from mike90045)
    Scoraig Wind "Recipe Book" for DYI Turbines (like here, more wind discussions)

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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