OmniCel ER14250 3.6V 1/2AA Lithium Standard Battery Button Top, 4 pack
Nominal capacity: 1200 mAh Open circuit voltage: 3.66V (at +20C +68F) Nominal voltage: 3.6V (at 1mA +20C +68F) Storage Temperature: +30C max (recommended) Operating temperature: -55C / +85C