USB Lipo Charger





Introduction: USB Lipo Charger

In my first "instructable"I have said that I had the project to make a lipo charger.
This the first test !
It's not the final version .

It's the first time i soldering smd parts.

dont worry it's very easy;
put little past soldering on the pad  to the board
put the smd
solder with a little hot air gaz soldering iron or hot air station .
the past make all the job !!

This version is with load sharing
The mosfet disconnect the battery from load when the usb is connected
The load is directly powered by usp when the battery charge

Step 1: Shematic

this is the new version of the shematic

change are :
- remap the mosfet
- remap the exit connectors
- remap the shunt

Step 2: Board

the first version : dont order it it's fail !!!

the second version

the price is 3.30 $ for 3 board

The last version i ordered

 New version V2.0( not tested) of my lipo charger. Change the mosfet implement error. Change the shunt implement on the bottom. Add DIP switch from TE Connectivity

Step 3: BOM

C1   4.7 uF             CAP0805            0805                                                                                                  

C2   4.7 uF             CAP0805            0805                                                                                                 

C3   1 uF               CAP0805            0805                                                                                                


JP1  USBPCB             USBPCB             USB-A-PCB      USB Connectors                                                                                 

JP2  M02POLAR_LOCK                                                                 


LED1 Charge             LEDCHIPLED_0805    red

LED2 Full               LEDCHIPLED_0805    green


R1   150                RESISTOR0805-RES   0805           Resistor                                                                                        

R2   150                RESISTOR0805-RES   0805           Resistor                                                                                       

R3   15 K               RESISTOR0805-RES   0805           Resistor                                                                                       

R4   33 K               RESISTOR0805-RES   0805           Resistor                                                                                        

R5   12 K               RESISTOR0805-RES   0805           Resistor                                                                                       

R6   8,2 K              RESISTOR0805-RES   0805           Resistor                                                                                        

R7   5,6 K              RESISTOR0805-RES   0805           Resistor                                                                                       

R8   100 K              RESISTOR0805-RES   0805           Resistor                                                                                       

U1   MCP73831           MCP73831           SOT23-5        Miniature single cell, fully integrated Li-Ion, Li-polymer charge management controller IC-09995

Step 4: Fail

I make an error with the implement of the mosfet.

but when i receive my board i want to test it .

i put the mosfet on an adapter and wire it on the board

and it works!!

Step 5: Fail 2

be carreful when you insert your lipo : if reverse it you'll burn the MCP 73831



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    I don't understand the maximum current output of the MCP73831 chip. Could I output about 700 mA to my circuit and say 100 mA to my battery?


    I am looking for load sharing, thanks for sharing this :-)

    What MOSFET and diode that you used ?



    so do the second revision boards work out of the box or do I have to fix the mosfet issue and if so what was the problem with the mosfet so I can fix it and print the board

    hi my friend
    thanks for your interest the (second) third version is arrived yesterday in my mail box!!
    i'll test it and update my instructable.
    if you want i can send you the eagle files

    Thank you so much, if you could email me the eagle files that would be awesome, spitman94@gmail[dot]com. Could you also let me when know when you update the unstructable.

    it's on the road !!

    your comments are welcome