Do to screwing up my latest cell phone I have activated my old cell phone till the discount kicks in Feb 1 when I plan on getting a new one. My old cell phone battery has just all but give up and I don't plan on buying a new battery for it till next week. Course the battery in my screwed up phone wont fit the old phone either.

This past summer I was reading an artical I think it was in Scientific America showing how build your own cell phone battery from a 9 volt battery with a resister in line. Question is what was the circuit and components for a cell phone with a 3.7 volt battery in a Kyocera KX414 phone?

Well you simply need to drop the voltage from 9v to 3.7. You can more acuratly do it with a regulator, so the voltage doesn't dip until the battery is nearly dead. 9v batteries arn't terribly capacious though, I hope you know.

If the battery from your old phone is close to the same size as the new phone, you could adapt it to work even easier, assuming they're both lithium ion batteries.

[This message has been edited by Jax184 (edited 01-26-2007).]

quote Originally posted by Jax184: Well you simply need to drop the voltage from 9v to 3.7. You can more acuratly do it with a regulator, so the voltage doesn't dip until the battery is nearly dead. 9v batteries arn't terribly capacious though, I hope you know. If the battery from your old phone is close to the same size as the new phone, you could adapt it to work even easier, assuming they're both lithium ion batteries.

I knew that, sure I did.

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Ron
Land of the Free because of the Brave. Most gave some, some gave all.
My imagination is the only limiting factor to my Fiero. Well, there is that money issue.

It wasn't a regulator in the circuit just a resister. Maybe it was Popular Science I read that in.