Tadian SL350 1/2 AA Lithium Battery from the Battery Company
Varta Lithium CR 1/2 AA 700mAh 3V Batteries Blue | Dressinn
RS PRO Lithium Thionyl Chloride 3.6V 1/2 AA Battery | RS
EEMB ER14250 LS14250 1/2AA 3.6V 1200mAh Lithium Battery half aa batteries Li-SOCL₂ Non-Rechargeable Battery for Dogwatch Dog Collar and Some of Movement Monitor/Home Security/Alarm System: Amazon.co.uk: Electronics & Photo