how to make a mini electric motor that generates on battery?

Question

how can i make one like the ones that are used to move wheels on cars?

also when i say cars i mean SMALL BATTERY CARS NOT REAL CARS!

Answer 1

do you mean one that runs on DC batteries? making an electric motor, that is a DC motor is very tough unless you have access to specialized tools to wind the motor and can get the magnetic material needed for the motor and you need access to integrated circuits to control the motor. You're better off buying one, than attempting to make one unless your doing a science project and studying motors. there are two basic types of dc motors, brushless dc motors and brush dc motors. and within each type of dc motor, brush and brushless, their are several different types, with various tradeoffs for efficiency and power. Brushless DC motors are the most efficient, and dont have the contacts( brushes) that wear out, and are the smallest per generated horsepower. Unfortunately the magnetic material and control electronics makes this type of motor fairly expensive. Most Electric Vehicle Wheel motors are using the older brush type of DC motors. To make one of these you need magnetic material called a stator composed of one or more pairs of N/S magnetic poles, and rotor to which the axel that drives the wheels is attached, and for each pole of the rotor (N/S -Pair), you need one set of widings and a pair of brushes to alternate the current and a controller circuit to switch the DC current from your battery between one winding of each pole and the next. Sounds complex. Yeah it is.

Answer 2

If you have a motor that will run a car with a battery, it will also generate electricity. Instead of putting a battery on the terminals, you have to turn the motor to generate electricity, say by letting the car roll down a hill.

You cannot have a battery that runs a motor that turns a generator that charges the battery.
This is against the Laws of Thermodynamics.

Answer 3

Actually you can have a DC motor run by a battery turn the shaft of a second DC motor which will generate power.

In industry these are called MG sets for Motor/Generator and they are used when specialized power is required. Have an AC motor turn a DC generator for example....

For your experiment two common DC motors from Radio Shack will do nicely. These have permanent magnets which is why it will be easy to generate electricity just by spinning the shaft.

Your experiment will demonstrate how a motor consumes electric power and a generator creates electric power. You can measure efficiency of the conversion process by comparing input power consumed to output power generated. You can transfer power from one battery to another (with losses) Use a charged NiCad battery to run the MG set and charge a second NiCad. Then run tests to see how long a lightbulb will run on the charge. (further illustrates losses across the MG set)