How do I build a bicycle powered phone charger?

you want to charge your phone by riding a bike?

Try this or maybe this

@forestGeek: Good sites, thanks.

@Comedian: Why on earth not? :)

This could work easily but I wouldn’t recommend it. I only charge my phone with the wall charger. The battery could last for five years or so if you only use the wall charger but only one year or so if you use a car charger all the time.

This is because your car puts out slightly different voltages at different states of drive and idle. It’s sending slightly more juice down the line when you’re driving and slightly less when you stop. This is what tends to wear phone batteries out.

You can imagine how this same type thing would happen as you stop and start pedaling your bike.

Batteries are getting better all the time and the new lithium ion are suppose to be immune to this phenomena (but they are not).

@Richard: Tuche