Talk:How to Build a Mechanically Powered Battery Charger for LED Lighting

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• Performance and Discussion

-Charging current depends on the difference in voltages
 Assuming constant battery internal resistance, I=(V-Vbatt)/Rbatt
-This design only works with a brushed DC motor where rpm is proportional to voltage, and 
 torque is proportional to current
-Note: the battery voltage increases with charge.
 The voltage of a fully charged battery is often greater than its nominal voltage

• Wiring the Charger

-V=IR not applied correctly.  A resistor is not needed, however to ensure the battery 
 doesn't overcharge, the rpm should be limited to the charged voltage of the battery.