139Views4Replies

Author Options:

Battery charger circuit?

Hi,
Can someone help with a simple battery charging circuit? It is to be attached to bicycle dynamo to charge the 4 V battery. Now the power generated by the dynamo would be fluctuating depending upon the RPM. So need to build a charger that would ensure constant supply to the battery. Preferably simple and economical circuit as this would be used on some charitable work. 

4 Replies

rahuldj (author)2014-12-25

Will check for battery type, am not from tech background so didn't foresee it, but thank you all for the help !

seandogue (author)2014-12-24

Lead Acid? Lithium Ion? Nickel Cadmium? etc? Each chemistry requires a different charging paradigm and most are far less forgiving than say, Lead Acid.

iceng (author)2014-12-22

Not being familiar with the LM715 Op-Amp,

I would generate near 4 volts like below and

"then feed that into the charge controller that is designed for that battery." as

Mpilchfamily said.

mpilchfamily (author)2014-12-22

Use an LM715 to take the voltage from teh dynamo and regulate to 4V. See the data sheet for the LM715 for a basic schematic and instructions for setting the correct output voltage. Then feed that into the charge controller that is designed for that battery.