Ryobi 18V to Skil 12V Adapter

This is an extremely niche project, but it lets you use a Ryobi battery to power a Skil Tower Light. Lowes was selling these lights for $50 each so I got two. One was left unmodified and the other was modified to use Ryobi batteries since I have a lot of them and they are higher capacity. Although this tool supports 20V batteries, Skil 20V batteries use a communication protocol with the tool that cannot yet be faked out so it's not possible to directly connect the Ryobi batteries to the Skil tool.

The Ryobi battery adapter is from Thingiverse and requires the contacts as listed on that model.

Then the two other pieces needed are attached. The first one slots into the Skil battery slot and the other one is a support piece for the bottom of the battery. You'll also need LM2596 DC to DC Buck Converter with Heat Sink. The heat sink is important for running the light at full brightness. Finally you need a 15k resistor or equivalent to trick the tool into seeing the battery's temperature. Attach what you have and see if the tools works. If it's wrong, the tool will shut off in a few seconds.

I used various screws I had here so I can't provide specifics, but it should be easy to make something work. For the bottom mount, I drilled holes into the light's case and ran the screws directly to the plastic to hold it. I attached a photo of the inside so you can see where the wires are, but there are no wires inside of the tool here.

Of course the battery needs wired to the input of the converter and the converter's output needs wired to the tool. I chose to solder because this is a permanent installation. You'll also need to attach the resistor. See photos for pinout.

Fusion 360 project included if modifications are needed for other tools. I had to make a very specific shape for the design of this light.