Those are battery holders with integrated wire connectors for AA and AAA batteries. It is partly a derivative of http://www.thingiverse.com/thing:9805 .
The electricity from a battery is conducted to wires through M3 countersunk screws and M3 embedded nuts. Wires are fixed between holder connectors and embedded nuts. A battery holder can be mounted using two M3 countersunk screws.
There are several holder models published both for AA and AAA batteries. Their filenames start with a battery type followed by an amount of batteries in a holder.
| AAA_1_Battery_Holder.stl | 426.2KB | |
| AAA_2_Battery_Holder.stl | 815.1KB | |
| AAA_3_Battery_Holder.stl | 1.2MB | |
| AA_1_Battery_Holder.stl | 407.9KB | |
| AA_2_Battery_Holder.stl | 797.7KB | |
| AA_3_Battery_Holder.stl | 1.2MB | |
| AA_4_Battery_Holder.stl | 1.5MB |
