Author Options:

How can I use a 9volt charger on a 3.6 battery 700 mA? Answered

So Im doing this project where I have a 9 volt charger and I need to charge a 3.6 volt 700 ma battery. How would i go about charging this battery? I tried to use one resistor but it got extremely hot, hot enough to melt plastic. 

4 Replies

steveastrouk (author)2013-02-19

That's a lithium battery. Build a lithium battery charger, and be careful. You may have been lucky not to explode the battery.


Select as Best AnswerUndo Best Answer

jnajmy (author)steveastrouk2013-02-19

What size regulator would I need to use to bring the voltage down from 9 volts to 3.6 volts at 600 mA?
This is the battery I want to use:

Can I use this to charge the battery?:

If not can anyone help me figure out whats the best way to charge that battery?

thanks for the help!!

Select as Best AnswerUndo Best Answer

mpilchfamily (author)2013-02-19

It;s best that you don't try to use that charger on any battery other than what it was designed to charge. Find the correct charger and use that.

BTW, a resistor alone isn't going to bring the voltage down. A resistor will restrict current flow. You need to use a voltage regulator in order to bring voltage down. Yes a pair of resistors set up as a voltage divider will reduce both voltage and current but it's best to use a regulator.

Select as Best AnswerUndo Best Answer


V=IR, of course it will bring the voltage down. That said, a regulator at the very very minimum is needed here.

Select as Best AnswerUndo Best Answer