Dynamo kit?

Question

Is it possible to connect a bicycle dynamo to battery powered lights carry rechargeable batteries. This way when my bike stops the lights stay on. Is it also possible to integrate solar power to aid up charging the batteries?

Answer 1

This is certainly very easy to do - and indeed there were a number of commercial systems around some years ago.

Incorporating a voltage sensing device in the dynamo circuit so that it switches over to battery circuit when the dynamo input drops is the way to go.

A solar cell large enough to charge your cycle lamp is likely to be too large to carry on your bike , ( would be around a square foot!!) though you could mount it on your back pack.

Answer 2

yes.

What is the voltage of the lights? Perhaps 6 volts? The dynamo has to put out enough voltage to charge the batteries, in the 6 volt case, you would need at least 8 volts. Put a power rectifier (1 amp should be enough) between the generator and the battery to prevent the generator from discharging the battery when it is not turning.

The same thing with the solar cell, it needs to put out 8 volts and you should put a diode between the cell and the battery for the same reason. But, as another answer says, getting any energy is going to be difficult, as how do you align the cell with the sun when you are moving.