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USB and battery powered light with cree q5 bulb.


Nov 9, 2015
Nov 9, 2015
ok. hope i can explain this as simple as possible.
I have a cree q5 bulb that i got from a flashlight(picture of flashlight attached) which is damaged. the bulb is fine though....
i want to use this bulb as a lamp powered by both usb and battery(li-ion 3.7v). here's how i want it to work:
there should be port(s) on the lamp casing( i will make a custom case out of wood) .

when i plug a usb cable in it, lamp turns on but doesn't charge battery(only to power the lamp) and when i unplug the lamp it turns off.

then i can use it with battery....just flip a switch and it turns on.

Problems so far:
i cant figure out a way how to charge the battery when it is inside.
note:- i dont want lamp to turn on when charging. the battery is salvaged from a broken mp4 player.

how do i go to build the circuit and how many volts/current are needed to charge the li-ion battery? ? what are the additional materials needed ?
i have wires,switches, usb ports(2 male and 1 female),bunch of other LED's. i can get resistors from an old broken TV...

Additional features i thought to add in this lamp:
be able to change brightness of the lamp. i read i could do it by variating the voltage using a potentiometer.( click the link to check the ebay item)


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