I bought four ER14505 LS14500 AA 3.6V 2400mAh lithium batteries and battery holders for PCB and thought I should use the rest of my Moteinos. I had three of them laying around that I don't use.
For this project I use the same code as my other sensors around the house, so the only job was to get it on a vero board, solder and box it. Since the LS14500 battery works down to -40 degrees Celsius, it will do just fine in the deep freezer.
It's hooked up to my Moteino gateway and Raspberry Pi 2 Domotiga server. I guess I will box the two remaining Moteinos in the same way and cover two other rooms at home, or maybe in the fridge. I bought everything on Aliexpress.com, except for the Moteinos.