Many months ago I had a LED flashlight... that I left some cheap batteries in. After awhile it was completely stuck, and some time later I eventually unwrenched it. I tried the tricks to get it out, even pbblaster and the tiny pliers. Then it sat on the porch for weeks.

Rather than throw it away I thought of building it up from AAA to AA batteries and an octagonal flashlight that can shine at 45, 90, 135 degrees...

Supplies

Saw, hammer and nails, screws, plywood, scrap wood, wood glue, solder and 2xAA battery case.

Step 1: Hacking the Flashlight

As you may know, electricity needs a circuit and the positive end goes forward into a flashlight, with the negative completing the circuit at the end of the tube with its metal outer casing. Generally a tail end switch connects this when you tap the button to turn it on. To just see if this was salvageable, I hacksawed at the end of the AAA battery area of the flashlight. 2AA batteries give 3 volts same as 2AAA batteries and so I tested the LED by touching the red to the center and the black to the outer metal of the LED module hacked from the flashlight... and it worked! Not destroyed by corrosion. On to the next step...

Step 2: Planning and Starting the Case

To keep it somewhat small, I used plywood for the casing of the flashlight, and marked up where to cut it into an octagonal shape - a rectangle with chunks taken out of it.

I nailed the wood into position after drilling, to keep it splitting. If it does split, just move and nail the next section and cut that off - as you can see in the photo.

Step 3: Switch It!

An electrical switch can be something you buy or repurpose, but essentially it just needs to be two metal contacts. To keep a homemade feel to this I decided to screw in a wood knob cut out of the wood.

This is doing the job of the end switch, and just like the end switch on a flashlight, I set a wire from one end to the negative LED (outer) and one end to the negative from the battery holder.

A metal plate on one side completes this and turns it on if the two screws are covered by the plate. Screwing this in until it touches, this makes a neat home-made switch.

Step 4: Fitting It All Together

It was sort of tricky fitting the AA holder and the light, and a switch - the solder doesn't take very well, and just blobbing it on eventually got a pretty solid connection - carefully, so that the red is center, and a second black connected to the power switch.

After drilling in a screw (still allowing slide-rotating to replace the batteries), all was set up and working - on a flashlight you can point downward, upward, AND flat like a normal flashlight.