The local makerspace needed one sign portable, to set out during "Repair Cafe" nights: something to set out on a pair of chairs in the parking lot to direct people to the front door.
It turns out you can get a 3d-printed DeWalt battery connector for thin money on eBay, and our space uses DeWalt hand tools and has a bank of chargers for the battery.
You can also get DeWalt batteries.
The sign will nominally use 700 ma during display, so a DeWalt 20 volt battery pack should comfortably run the sign for more than 10 hours - plenty of time for one evening.
For the 2nd sign, a DeWalt connector was attached to the side, and the power connected to the original DC to DC power supply.
In use, slide in a battery and the sign boots and shows the programmed information. At the end of the night, remove the battery and stick it in a charger.
The ease of implementation got me thinking: the availability of the clip makes it easy to use DeWalt batteries in hacker projects.