this coin cell holder fits the tiny CR1225 batteries which are
12.5mm or 0.5 inch across.
These little batteries can run up to 4 LEDs brightly. We have also added our smaller slide switch to this package.
The slide switch dimensions:
Connect to lights by twisting the red wire on this holder to all the red wires on your LEDs. Protect the connection with shrink tube.
Same with the black wire, connect it to the remaining black or green wires on your LEDs.
How many lights?
We tested 4 chip lights and found them to be nice and bright. We don't suggest adding more than 4 as they would not be as bright Mega will be dim on this battery. How long does the battery last?
4 lights lasted for 7 hours before the battery needed a change. Fewer lights would be bright longer between changes.