Adafruit Waterproof 2xAA Battery Holder with On/Off Switch
Keep your power source safe and toasty in these waterproof 2xAA battery holders. They're just like classic switched battery holders, but designed for survival! The case has a rubber gasket around the edge of the case (its black and hard to see in the photos but it is there) and attaches together with 4 machine screws. What we like about this design is that the hexnuts are captive in one side and you can assemble/disassemble as many times as you need. There's a rubber-boot on-off switch (press to turn on/off). Use with any alkaline or rechargeable batteries for about 3V output.
As of January 31st, 2014 these can come either with the screwholes on the body of the battery holder OR on the outside. Both work the same!
Would work great with our waterproof DC power plugs (just use heatshrink to waterproof the solder connections)
We also have a 3xAA version when you need a little more power