Maker Pro
Maker Pro

Lithium Ion Charging USB Board


Jan 14, 2014
Jan 14, 2014
One of my friends commissioned me to turn an Xbox Controller into an arcade fighting stick. The controller is wireless but I plan on making it chargeable via USB.

I found an old laptop battery lying around which has 6 cells, 3.7v 2250mAh lithium Ion batteries. (CGR18650CE)

I realise that playing with li ion batteries can get dangerous very quickly so I wanted to make sure of a few things before I jumped straight into charging them.

I plan on just using one cell as that keeps it simple and is more than enough power.

I found this protection circuit that uses USB to charge batteries.

It recommends that the charging current be at least 37% of the battery capacity. Since its max current output is 400mA it is designed to work with 1Ah batteries (as it says).

What would happen if I tried to charge my 2.25Ah batteries with 400mA current? Would it just charge the batteries slower or would it actually damage them or not charge at all?

The charged and charging LED's would also still work correctly yes? (as long as it charges them)

Lastly, would it be safe for the the controller that the batteries are connected to to be used whilst charging the batteries?