charging batteries using motors

[ballbreaker]

I have searched the internet to find an answer but i didn't find what i was looking.

am trying to charge a battery by spinning motors but the obvious question is when i connect them the battery will give energy to the motors how do i stop the battery from giving power but to take power from the motor and charge?

also what other things i have to be aware of?

thank you

[waltr]

Simplest is a single diode to allow current to only go from the motor to the battery.

[Soeren]

Hi,

Hand spinning or by a windmill or similar?
If spinned by hand, either use gearing to get it spinning fast or use a stepper motor.

A stepper will take a couple of diodes, as there's 2 or 4 phases (depending on whether the motor is a unipolar or a bipolar type), but small steppers are very efficient with even modest spin rates.

[ballbreaker]

thank you for your response and am sorry that i didnt reply earlier

its going to be most likely a brushless geared motor (with permanent magnets) i have thought about the diodes but because am using 12V i thing it will quickly overheat wouldn't ? also if the voltage created gets higher than 12V can a 12V voltage regulator keep it down?

btw is the brushless motor  better as a generator rather than a normal dc motor?

[Soeren]

Hi,

its going to be most likely a brushless geared motor (with permanent magnets) i have thought about the diodes but because am using 12V i thing it will quickly overheat wouldn't ?

No. You just need to choose diodes that fits the output (V&A).

also if the voltage created gets higher than 12V can a 12V voltage regulator keep it down?

How much higher, at what currents and what specific regulator.

btw is the brushless motor  better as a generator rather than a normal dc motor?

Haven't ever tried one that way, but I'd think they were more efficient than a brushed motor - you'll need a rectifier for each phase winding though.