5vdc to 3.8vdc step down

Hey all i am in need of some help with stepping down a 5vdc to 3.8vdc so that i can power my phone.

The battery that's powering the phone is rated at 3.8vdc 1730mAh 6.57Whr.

What all would i need in order to step down from the 5vdc to around the 3.8vdc mark?

The USB 5vdc is rated at 5.1vdc 2.1A.

Any help would be great!

Are you trying to charge the battery or replace it with a power supply?

Telit has some good guidelines on powering their phone modules. A conventional phone has basically the same requirement.

https://www.telit.com/en/products/gsm-gprs.php?p_id=12&p_ac=show&p=47 and go to Telit_GE865-QUAD_Hardware_User_Guide_r15, page 31

You should note that mobile phones take current peaks up to 2 A, and are very difficult to provide a supply for.

I can't find the thread, but someone here had problems running a phone from a 3 A power supply, possibly because of the length of the wires that were used.

Trying to just power it, not charge it.

Try something like this. Make sure to follow the datasheet and build it inside the phone if you can.

https://www.electro-tech-online.com/custompdfs/2013/03/1528fb.pdf