Eveready ECR2450BP Energizer Lithium Coin Battery, Miniature, Pack, Nominal Voltage: 3 V, 620 MILAMP-HR Rated At 7.5 KOHM, Discharge Cut-Off Voltage: 2 V At 21 DEG C, Electrolyte: Lithium/Manganese Dioxide (Li/MnO2), Positive Terminal: Bottom/Sides, Negative Terminal: Top, Size: CR2450, 24.5 MM Leng