I got 8 AA cells and a dedicated charger from China today. They are high voltage for a AA. Over 1.8v charged. From China they came in 1.72v
I have some AA NiMH high capacity cells that are 1.35v charged, so I took one of each and the combined voltage is just under 3.2v Two AA alkalines fresh have that voltage. The single 3.2v LiFePO4 with dummy cell in a wireless wall thermostat was down to about 1/4 charge after almost 3 weeks, so I swapped them out for a NiMH and NiZn set and will report back when that set gets low. They should last a while. The NiMH is rated 2.5 ah, just like the NiZn, but I don't believe the NiMH rating. That's too close to the theoretical physical limit for that sixze cell and chemistry.