364, AG1, LR621, SR621SW Battery Equivalents and Replacements
LR621 and SR621SW are very popular coin/button cell batteries often used in wrist watches, small toys, remote keys, and similar small and compact devices.
LR/SR621 batteries are manufactured by many leading brands, and can be easily found at online shops and stores.
LR621 and SR621 batteries are 6.8 mm in diameter and 2.1 mm in height. They are commonly available as alkaline and as silver-oxide batteries.
Alkaline batteries are labeled as LR621, LR60, or AG1 batteries. Their nominal voltage is 1.5 volts, but as the battery is used, voltage drops quickly. Cut off voltage is considered to be 0.9 volts, but if these batteries are used for electronic devices, it is possible that the device has its 'own' cut off voltage, for example 1.1 or 1.2 volts - when the battery reaches this voltage, device will either shut-off, or starts to behave erratically.
Nominal capacity of LR621/LR60/AG1 batteries is around 12-15 mAh, when being discharged down to 0.9 volts. Generally, LR621/LR60/AG1 are used for toys, flashlights and similar devices where constant voltage is not of ultimate importance.
Silver-oxide batteries are commonly labeled as SR621, SR621SW, SR60, 164, 364, SG1, or even AG1.
Nominal voltage of silver-oxide batteries is 1.55 volts and cut off voltage is 1.2 volts. When the battery is in use, voltage drops slightly and stays constant during the use. As the battery gets fully discharge, voltage drops off sharply and below 1.2 volts, the battery is considered as being fully discharged.
Nominal capacity of SR621, SR621SW, SR60, 164, 364, SG1 batteries is in 18-23(25) mAh range.
When compared with alkaline batteries, SR621SW batteries, like all coin cell batteries have larger capacity, more stable/constant operating voltage, higher cut off voltage, longer shelf life and are slightly more expensive.
SR621, SR621SW, SR60, 164, 364, SG1 equivalent silver-oxide batteries are generally used in electronic devices like wrist watches, remote control devices, remote keys and similar. Although they are not as cheap as alkaline batteries, price difference is almost negligible - the use of SR621SW or equivalent silver-oxide batteries is recommended even in kids' toys and similar 'electric' devices.
Long Story Short: if you need good LR621, LR60, AG1, SR621, SR621SW, SR60, 164, 364, or SG1 battery equivalent, go for battery labeled as SR621SW (SR621 Silver-Watch) battery - it is silver-oxide battery with stable voltage and high capacity.
For latest offers and prices, check SR621SW watch battery Amazon link (link opens in the new window).