Without any
USB to phone battery charger circuit we can
charging phone battery using port on USB computer , but it will quickly damage the phone battery, and the battery will bulge. Because the voltage which was issued on usb is 5 volts , while the average-voltage phone battery 3.5 - 3.7 volts. That's why this USB to phone battery charger circuit is required , this USB to
phone battery charger circuit reduce votlage to 3.7 volt usb, but will not reduce currents and will make a
durable phone battery.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjyatKPUiAcsPVWHCAWvHC80o8BF4DxhSbWwrCil-BgHrIloRRqh9-pFgp4aNI3Fp-4mCL3H7moV9QaLPkWNUvVB45R1uNim-p-XOvd9SiRypkcAs9ri52ZTYK_j0tII1pNattE3D2XhfxC/s400-rw/usb+to+charger+phone+battery.jpg) |
USB to phone battery charger circuit diagrams |
List of components :
R1 : 1 K
R2 : 330 R
R3 : 4K7
R4 : 300 R
R5 : 27R
D1 : 4.7 volt zener /1W
C1 : 100uF/16V
Q1 : BC548
Q2 : BC558A
LED1 : Green Led
X1-1 : Vcc USB
X1-4 : Ground USB
X2-1 , X2-2 : To phone battery
See also this printed circuit board ( PCB ) of USB to phone battery charger :
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiAQlMwIfDZVo6hbpuggQwCRmMRO169GSq2mURzGvPp3f5LkcN5UdiQXZiM6TZQO3s883R8oQu9iI4gxO2MCyb-Tt5PFWXi6AbqQpiExLjTjBEAj7pV6L6hdbycBU4fvVzjIKeN9_grGtNU/s400-rw/Usb+to+phone+battery+charger.jpg) |
USB to phone battery charger printed circuit board |