SR626SW Watch Battery Equivalents
SR626SW batteries are button/coin-cell batteries commonly used in wristwatches, calculators, medical instruments, laser pointers, LED micro-flashlights, and similar.
SR626SW batteries are manufactured by most battery brands but often feature different labels, leading to certain confusion among their buyers.
SR626SW Battery Features and Specifications
SR626SW battery is silver-oxide button/coin cell battery featuring physical dimensions of (D x H) 6.8 x 2.6 mm (~0.2677 x 0.10236 inches). Also, its nominal voltage is 1.55 volts, while capacity differs from ~23 to 30 mAh and it highly depends on the battery load and temperature.
The cutoff voltage of SR626SW batteries is ~1.2 volts, although it also depends on the cutoff voltage of the powered device.
For example, while some manufacturers claim that their SR626SW batteries feature capacity even more than 30 mAh, note that the typical test drain current of these batteries is ~30 μA - if the drain current is well below 30 μA, then capacity may appear in 30+ mAh range.
Another important feature of the silver-oxide 6.8 x 2.6 batteries is the drain current - while years ago some batteries were manufactured as low-drain SR626SW batteries intended for, for example, watches without LED lights and/or alarms, and some batteries were manufactured as high-drain SR626SW batteries intended for, for example, watches with LED lights and/or alarms.
However, with the advancements in chemistry, most brands have switched to multi-drain SR626SW batteries, which feature good low-drain capacity but are also able to provide relatively large pulse currents.
For example, Energizer multi-drain SR626SW battery features a nominal voltage of 'only' 24 mAh, but it is able to provide very stable voltage and very constant current during its lifetime.
Silver-oxide batteries also feature a relatively long shelf-life between 4-6 years, which also depends on the storage current.
The very same Energizer multi-drain SR626SW battery retains 70% of initial charge after being stored for 4 years at 40°, 90% of initial charge after being stored for 5 years at 20°C and >95% after being stored for 8(!) years at 0°C.
For more details about this battery, feel free to download Energizer 377/376 Datasheet pdf file.
Like all similar batteries, SR626SW batteries feature other labels, including SR626, SR66, 177, 376, 377, SG4, etc.
LR626 Battery vs SR626SW Battery
LR626 battery is an alkaline (D x H) 6.8 x 2.6 mm (~0.2677 x 0.10236 inches) battery. Although it features the same physical dimensions, alkaline LR626 batteries feature a nominal voltage of 1.5 volts, a cutoff voltage of 0.9 volts, and capacity in the 12-20 mAh range - if the powered device can operate below 1.2 volts (cutoff voltage of SR626SW battery). If not, then the actual capacity of the LR626 batteries is even lower than 12-20 mAh.
LR626 batteries are in general inferior to SR626SW batteries in many ways - they have less stable output voltage, smaller capacity, lower cutoff voltage, shorter shelf-life (2-4 years), and similar. But, they can be found at a very acceptable price and are often used for powering electric and not electronic devices.
Like all similar batteries, LR626 batteries feature other labels, including LR66, AG4, etc.
Note: Some manufacturers use labels interchangeably for both alkaline and silver-oxide batteries. In that case, be sure to check the voltage and the battery description. SR626SW battery is a silver-oxide battery with a nominal voltage of 1.55 volts.
SR626SW Battery Safety Issues
SR626SW batteries are small and shiny objects that can easily get swallowed by kids and pets - that is the reason why most small batteries come in 'child-safe' packages.
If the SR626SW battery gets swallowed (or any similar battery), call local emergency services right away and explain what happened and act according to their instructions.
SR626SW batteries are NOT toxic since they don't contain mercury, cadmium, and similar toxic, heavy metals. But, when swallowed, they can cause electrolysis that produces very aggressive chemicals that cause severe internal burns - SR626SW are perhaps not as dangerous as, for example, larger CR2032 batteries, but nonetheless ... Please, take this warning seriously and never leave button/coin or any similar battery unattended when kids and/or pets are around ...
Long Story Short: When looking for a new SR626SW battery, go for the batteries from reputable brands tried and tested by many users in real-life situations.
Good SR626SW battery features a nominal voltage of 1.55 volts, a rather stable voltage during use, and can be used even after years of being stored at room temperature.
And again, keep them away from kids and pets.