hi every one im glade i found this amazing forum. its realy useful. i get a rechargeable battery for iphone from a friend. the board charge the battery but its not charge the phone. i dont wanna to fix this one. i want to use this battery to run my flash light its need four AA battery.
can u help me please how to designe a board its charge the li-pol battery and run my flash light. but i dont wanna to destroy my light.
thank u.
this is the pic.

 

Welcome

When you said design, do you mean start from scrap ?

 

thank u. if i can modify the current board i will not mind. if its easier to build from scrap please tell me how.

 

It's not easy, believe me.

Did you try googling for anything that might appeal you

 

im searching from 3 days i couldnt find any thing. if there is a board sample i can find the component and solder it together.

 

That battery in the picture is bulging.
Check it, if it is like a pillow then you cannot use it. It's faulty.

Second we need to know whether you have a lipo or li-on

 

thank you for keeping up with me. the battery is not bulging. its perfect like new one. the mobile phone camera im using is too old. the battery is lipo. i dont wanna to charge the battery with AC 110v. i will use dc 5.0v charger.

 

OK..Now you need to share some info about the capacity and no of wires coming out of the battery

 

the battery has 2 wire black and red. its full charged. its give in those wire 4.11volt, 8.33a. capacity 2250mah. i want to use 5.0v or 3.7v dc charger too charge the battery, and over charge protect. and the flash light use 4pcs AA battery.

 

Then it is a 3.7V lipo. Fully charged will give u 4.2V.

U cannot use 3.7V to charge unless you have boost circuit to increase the output.
It will be easier to use a 5V PSU.

Now it's up to u to do a home work.

Search for Lipo charger circuits and learn about it's charge chemistry.

I have not done a lipo charger but I did a Li-on charger for my battery drill.

But I do not think it is impossible

Try google and decided what appeals you. Then show us what you decided.

I do not have time to design anything these days. I am in the middle of a project but I can advice on anything possibly. You need to do the hard part. It will help you to learn.

 

thank u very much i will see what i can find then share it with u.