Our OpenTRV hardware (AVR ATMega328p) can easily do a year on a pair of AAs, sending one secure stats frame every 4 minutes, eg our REV2 design: https://github

Our OpenTRV hardware (AVR ATMega328p) can easily do a year on a pair of AAs, sending one secure stats frame every 4 minutes, eg our REV2 design: https://github.com/opentrv/OpenTRV-Arduino-V0p2/tree/master/Arduino/hardware/REV2/20140224-r2643-V0p2-Arduino-REV2-4th-cut/V0p2_Main_PCB2 https://github.com/opentrv/OpenTRV-Arduino-V0p2/tree/master/... The processor is down to typically a couple of uA waking every couple of seconds to see what needs doing. See the log at the end of this as I was originally driving the power down: https://github.com/opentrv/OTRadioLink/blob/master/content/OTRadioLink/utility/OTV0P2BASE_PowerManagement.cpp https://github.com/opentrv/OTRadioLink/blob/master/content/O... Our target is in fact 2 years life, including driving the valve, off a pair of AA NiMH hybrids. Slightly longer term our aim is to get off batteries entirely: https://github.com/opentrv/OTWiki/wiki/Energy-Harvesting-Feasibility https://github.com/opentrv/OTWiki/wiki/Energy-Harvesting-Fea... which is why I spent Tuesday at this meeting: http://www.earth.org.uk/note-on-Energy-Harvesting-Dissemination-Event.html http://www.earth.org.uk/note-on-Energy-Harvesting-Disseminat...