Originally Posted by
Richard Cranium
Did you build with an AC generator and rectifier? Are there pre-configured ICs/PCBs that can maintain say 8.5V so as to charge Li Ion cells - even though the current may be low at slow speeds?
I use a hub dynamo and currently Eneloops for the batteries. Within an usual application and under the requirement of high efficiency, you are basically on your own in terms of electronic design. An IC is just a compact realization of a circuit that has common applications.
Originally Posted by
Richard Cranium
You can charge a big battery in 3 hours at 1.5A -but I'm thinking a generator could never deliver that kind of current at low RPMs -maybe more like 30-40mA...... I wonder what the silly hand crank radios deliver, maybe 10-20mA@3.5V?
A bicycle dynamo maxes out at 0.55-0.6 A. In my case, I may draw 0.3 A with pretty empty batteries. Most often I might be drawing 0.1A or less. The essence is to fill batteries when there is excess power and use that reserve power when there is a deficiency.