4 NiMH cells just aren't enough to power the arduino and sensors that I want to use. 5 might do.

I designed this 5 AA cell holder to hold rechargeable cells and power my Arduino projects.

I first tried using the well designed battery pack - http://www.thingiverse.com/thing:5079 - but had problems with the clearance necessary to allow for the bolt head contacts. The bolts and washers are additional components that I don't want to have to use for batteries.

My design uses solid copper wire for the battery contacts and interconnects. Soldering the wire ends is optional and I imagine will increase the physical lifetime of the pack. The wires should be wrapped twice through the wall to give good contact with the battery. The wire channel design has a land to cause the copper to extend out to press against the battery. There are wire channels on the inside and outside of the box to correctly align the wires and keep the package neat.

The alternate design has some corners built into the top to center an arduino above the battery box and hold it steady. It was designed for http://www.thingiverse.com/thing:8706 this Arduino holder, which I use to protect my furniture from the pins at the bottom of the arduino, and the contacts from short circuiting.

The packs can be stacked to produce a split power system, or 12V