GutAlkaLi LR41 Battery Pack of 20 – 1.5V AG3 Batteries for Watches, Hearing Aids, Glucometer, Key Fobs and Small Electronics – Silver Oxide Chemistry Provides Stable Voltage and Long Lifespan: Amazon.co.uk: Electronics
100 PCS AG3, 1.5V Alkaline Thermometer Battery, High Capacity 35mAh, UK Seller | eBay
50 X ASSORTED Watch Cell Batteries AG1 AG3 AG4 AG10 AG12 AG13 for Toys, Watches | eBay