I'm a bit new to the whole electronics / Arduino / general tinkering hobby, so please excuse me if I overlook simple things. I'm working on creating a weather station type set up. Currently I have a Raspberry Pi that has a DS18B20 that is working. I'm looking to add in a wireless outdoor sensor. I currently have an Arduino uno, a DS18B20, a DH11 humidity sensor, an Xbee and a 4 x AA battery pack.
Everything appears to work well, when I put the sensor outside for the first time last night it was returning data and chugging along happily. It appears as though this lasted for 5-6 hours and then the remote sensor died for some reason. When I retrieved the sensor, it was still powered (lights on and everything) but the Xbee was no longer able to connect to the Xbee router. My first troubleshooting step was to remove the battery pack and use a USB cable - doing this fixed the issue. This leads me to believe this is an issue with the battery pack. So, to my question:
Is this the best setup for an external sensor? This is just a standard 4 x AA holder with a 2.5mm pin soldered on to it + a transistor in line to bring it down to the 5V range. Do you guys think this may just be related to the cold (before it died the temperature was down to about 20 degrees F). Any advice would be greatly appreciated.