What DC motor should you use

What you want to look for is a surplus permanent magnet DC motor and pay attention to the RPM, shaft size, amps and voltage. You need to look for a DC motor with a LOW RPM rating. The reason for this is because when we use a DC motor as a generator it must spin much faster then the rated RPM to produce the rated voltage. Your goal is to obtain a DC motor with HIGH voltage (over 12v), HIGH current and LOW RPM rating. An ideal motor would be one rated under 400 RPM at 30 volts. When this is used...

Simple Charge Controller Circuit

Electrocar Controller Simple

The above diagram shows the simple charge controller circuit. The incoming battery voltage is divided in half by a pair of 3.3K resistors, so the trip points are adjusted to one-half the desired levels. Start at 14 volts for the trip points. The actual trip points will depend on your particular batteries, but a good starting point is 14.5 volts for full charge, and 11.8 volts for discharged. In this case, the trimpots should be adjusted to read 7.25 volts at TP-A and 5.9 volts at TP-B. You will...