Charging a Battery with a Wind Turbine?

Helmut

January 25, 20110 found this helpful

Hi Tom
Don't worry about the current. As long as the voltage is within specs, take all the current that the batteries can absorb. The batteries regulate the actual current. If you push too much current, the battery resistance rises and the current flow is reduced automatically.

You just have to keep the voltage within reason.

The way you do that depends on the type of generator or alternator you use. With a Permanent Magnet alternator and rectifier, you use a power-supply type voltage regulator and simply waste any excess as heat.

If you use an automotive type alternator, then you use an automotive type regulator, that is matched to THAT alternator. Large diameter, low speed alternators from old trucks or tractors are the best. It is no big deal changing the bearings and the slip-ring brushes in them.

Old 60's alternators will last until you stop changing the bearings every five years. For the belt, use a limp, flat toothed belt, not a V-belt. In a light breeze, that will make the difference between idling and charging.

Add a bypass switch to the voltage regulator, that
A) flips the positive lead from the alternator to go to an outlet instead of the battery bank
and at the same time
B) flips straight 12 Volt from the battery to the alternator's regulator input line (instead of what the regulator produces)

Then you can weld with the windmill output and run commutator/brush type power tools like drills and grinders with it. I built quite a few barrel stoves that way.
Just don't let anybody plug a capacitor start motor into that outlet!

If you have a large windmill, use a brushless welding generator made to be powered by a Diesel engine. With those, you HAVE to use the regulator made for it, even if you have to rebuild it one transistor at a time. Set it for fixed Voltage / floating Amperage, and set the voltage to suit your battery bank.

Have FUN!
DearWebby
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