Changing battery power to be USB power on small LED device

[markronz]

Hey everyone.  Just hoping someone might be able to lend me a little electrical knowledge.  I have this small device.  All it is, is when a switch is pushed it turns on a small LED light on the top.  Currently, it's battery powered by 3 AAA batteries.   I'd like to make it so that this thing is attached to USB to be powered instead.

Here are some pictures of the device.  Top View:


Switch:


Lit Up:


Bottom Batteries:


My real question is, is it as simple as chopping those two wires going to the battery bank and splice those over to a USB cable instead?  Anything I am missing?   I need to figure out what wires to use inside a USB too...

Thanks for any help!

[markronz]

Someone directed me to this url. Should be very helpful!
http://www.instructables.com/id/How-to-power-nearly-anything-off-a-USB-port/#step3

I think I'm just going to try it out.   Worst case scenario, I just have to replace the LED!

[RamjetR]

The quick answer is just chop the USB lead and connect the 5V and GND to the + and - of the battery contacts. The reason is simply that 3x1.5V is 4.5V and the additional half a volt will make at most 3-5mA difference to the LED. You won't even see a difference to the brightness. You'll be fine.

[danny_galaga]

The quick answer is just chop the USB lead and connect the 5V and GND to the + and - of the battery contacts. The reason is simply that 3x1.5V is 4.5V and the additional half a volt will make at most 3-5mA difference to the LED. You won't even see a difference to the brightness. You'll be fine.