Low self-discharge NiMH can last a long time in low power devices.
I've got a pair of first generation AAA Sanyo Eneloops in my bathroom scale. They've been in there for 1028 days. I have a pair in the display unit for a pair of wireless fridge/freezer thermometers. That went 395 days.
I've got first generation AA Panasonic Eneloops currently at 1079 days in one of the fridge/freezer thermometer sensors and 978 days in the other. 539 days in a humidity meter. 544 days in an analog wall clock.
I've got a pair of first generation AAA Sanyo Eneloops in my bathroom scale. They've been in there for 1028 days. I have a pair in the display unit for a pair of wireless fridge/freezer thermometers. That went 395 days.
I've got first generation AA Panasonic Eneloops currently at 1079 days in one of the fridge/freezer thermometer sensors and 978 days in the other. 539 days in a humidity meter. 544 days in an analog wall clock.