What is the difference between an LR44 and AG13 battery?
LR44 Battery Equivalent - TheBatterySupplier.Com
2x LR44 / A76 / AG13 1.5V Alkaline Coin Button Battery Cell, Watch, Car Key, Toy | eBay
GutAlkaLi LR44 Battery Pack of 20 – 1.5V AG13 Batteries for Watches, Hearing Aids, Glucometer, Key Fobs and Small Electronics – Silver Oxide Chemistry Provides Stable Voltage and Long Lifespan: Amazon.co.uk: Electronics