Oftentimes, perhaps for testing an on-board circuit or some other situation where a more robust power supply may not be available, you might have a need for a 2-cell battery clip. These can be bought for a small amount, but if the stores are closed or you're too lazy to make the trip, the 3-Minute Battery Clip is for you. As mentioned it takes about three minutes to build, and is almost completely free!
Step 1: Gather Ye Materials
You will need:
2 C-cells (this instructable will probably work with D cells and other sizes too).
A few lengths of wire. I used 22AWG solid core. Stranded core probably will not be as successful.
The plastic packaging from your batteries.
Step 2: Connect Terminals
Taking a short length of wire (about 2 inches/ 5 cm should be plenty), strip both ends to about 1/2 inch / 1cm. Using one of the ends, poke holes in the top and bottom of each side of the plastic holder. Each hole should be just large enough to accept the bare (uninsulated) wire.
You may find it easier to make these holes if you cut the end of the wire at an angle using the wire-cutters.
Poke one end of the wire through the hole in each side of the plastic holder, then bend into a nub or coil into a short spring-like structure. Make the length of the nub about half the length of the bared wire. This will hold the wire in position and provide enough force to hold the battery against the connection at the other end once in place.
For the top connections, take some longer pieces of wire - 6-8 inches/ 15 - 20cm. I suggest red and black for positive/ negative, but use whatever local conventions are in place. Strip one end of each piece to about 1/4 inch/ 5mm, or whatever makes sense to you - these ends will become the connections to your breadboard or circuit or whatever. Strip the other end of each piece to about 3/4 inch/ 2cm. Coil these ends into a spring shape, and poke each through the corresponding hole in the top of the plastic battery holder. You may need to work the wire in spirals to get it through.
Step 3: Secure Wires
Secure the terminal wires in place by twisting them together. You're done!
I used this setup to successfully power a couple of test circuits on a breadboard, as well as a temporary replacement for a circuit-mounted store-bought battery clip that got broken. It worked so well in the latter role that I just hot-glued it and left it in place. Battery replacement is quick and simple! It should work well in any situation where vibration is not a problem.