In this instructable I will be showing how to make a rechargeable flashlight that charges from your car. I got this idea as I often find myself using the flashlight that I keep in my car, but have come to it many of times with a dead battery. So my idea for a rechargeable flashlight started. It is fairly simple device, it is a flashlight after all. I did need to order one part from the internet. The light output of this flashlight is quite usable and probably perfect for being used around a car. With that said let's get started making the flashlight.
Step 1: Parts and Tools
3 white leds
5 10 ohm resistors
small switch ( I used RS # 275-0645)
li-ion or li-poly battery (single cell) (mine is only 70mAh)
li-ion/li-poly charger single cell ( I got mine from adafruit here, sparkfun also makes one)
USB mini B connector (cut mine off a usb cable)
power connectors for the board and battery (see picture)
power adapter/plug ( I used RS # 274-1569)
power jack (RS # 274-1577)
I used some plexiglass I had laying around
And finally for my housing an Altoids can
Solder Iron and solder
Helping hands (sure are helpful)
light (helps to be able to see what is going on)
Dremel with various bits (hacksaw and or tin snips can be used instead)
drill and drill bits
Sharp knife (always useful at some point)
Well hope I did not forget anything :)
Step 2: Making the LED Array
Step 3: Power Cable and Rough Layout of the Flashlight
The second picture shows all the parts connected to the board. It goes together so nicely.
If you are able to know would be a good time to test your voltage divider with a multi-meter. Plug the plug into a 12v source and look at the power coming to the pins of the USB plug (pins 1 and 5). You should see 6v, if you do good job, if you dont, make sure nothing is grounding out and your solder joints and connections are good.
Since I have assembled this I remembered about voltage regulators, could have used a 5v one... Anyways I would be most interested in anything that didnt consume alot of ghost power.
Step 4: Assembly
Step 5: Let There Be Light!
Some final thoughts;
I would like to figure out a better solution for converting the 12v of the car to 5v or 6v required by the charger.
Another thought that came to me after I had already made the light was to move the charger out of the light and into the car. This would allow for smaller enclosures for a better looking and feeling light.