SR527, SR527S, SR527SW, SR64, 319, LR527, LR64 Battery Equivalents and Replacements
SR527, SR527S, SR527SW, SR64, 319, LR527, LR64 are very small button cell batteries that often used in wrist watches, toys, remotes, and similar low drain devices.
These batteries are manufactured by the most battery brands and are easy to find in the local hardware stores and online shops, just be sure to order the battery of the right size and chemistry.
SR527, SR527S, SR527SW, SR64, 319, LR527, LR64 button cell battery feature physical dimensions of (diameter x height) 5.8 x 2.7 mm.
Like most of similar button cell batteries, SR527, SR527S, SR527SW, SR64, 319, LR527, LR64 batteries come in two chemistries:
- Alkaline batteries are commonly labeled as LR64 or LR527, and similar. These batteries are recognizable thanks to their 'LR' prefix, although some manufacturers use numbers only labels, but fortunately, they also describe the battery chemistry on the package of the battery.
The nominal voltage of LR64/LR527 batteries is 1.5 volts, but as the battery is used, voltage drops quickly, while its cut-off voltage depends on the device used. Generally, the cut-off voltage for the LR64/LR527 battery is around 1.0 volts.
The typical capacity of alkaline 319 battery is around 12-13 mAh, but it also depends on the battery temperature, drain current, battery age, etc.
- Silver-oxide batteries are commonly labeled as SR527, SR527S, SR527SW, SR64, 319, and similar. These batteries differ from the alkaline LR527 and LR64 batteries by mostly having prefix 'SR', although some brands again use 'numbers only' labels. In order to attract potential customers, most of the brands write down the labels of the models that their batteries actually replace.
Such practice sometimes increases the confusion which battery to buy, but actually it can greatly simplify the finding of the proper battery replacement.
Nominal voltage of SR527, SR527S, SR527SW, SR64, 319 batteries is 1.55 volts and the typical capacity is in 20-22 mAh range, which is significantly more than alkaline typical capacity of 12-13 mAh.
The cut-off voltage of silver-oxide batteries is ~1.2 volts, but this also depends on the cut-off voltage of the device in use. In any case, silver-oxide batteries have a much more stable voltage than alkaline batteries.
SR62/LR62/317 vs SR63/LR63/379 vs SR64/LR64/319 Batteries
- SR62/LR62/317 batteries feature a height of 1.6 mm and a nominal capacity of 7-8 mAh for alkaline batteries and 10-12 mAh for silver-oxide batteries.
- SR63/LR63/379 batteries feature a height of 2.1 mm and a nominal capacity of ~10 mAh for alkaline batteries and 16-18 mAh for silver-oxide batteries.
- SR64/LR64/319 batteries feature a height of 2.7 mm and a nominal capacity of 12-13 mAh for alkaline batteries and 20-22 mAh for silver-oxide batteries.
Although these batteries differ in just a fraction of millimeter, it is not recommended to switch from one battery size to another, even if the battery compartment of the device may accept larger/smaller battery - smaller batteries have smaller capacity and may not fit properly, causing contact issues, while larger batteries may get stuck in the battery compartment, even damaging the device.
Only when it is explicitly noted by the manufacturer of the device (watch, for example) that the device may accept and work properly using different batteries, one may replace one battery size with another battery size.
Long Story Short: if you need button cell battery 5.8 mm in diameter and 2.7 mm in height and you are not sure which one to get, follow these rules:
- LR527, LR64, alkaline 319, and similar batteries are the alkaline 5.8 x 2.7 mm batteries. They are cheaper, but also feature less stable voltage and lower capacity - since the proper operation of many electronic devices depends on the stable battery voltage, alkaline LR527 or SR64 batteries are not recommended for watches and similar units.
- SR527, SR527S, SR527SW, SR64, 319, and similar are silver-oxide batteries - they cost slightly more but have more stable voltage and higher capacity. If you have wrist watch or any similar electronic device, be sure to get a battery that is labeled SR527, SR527S, SR527SW, SR64, or silver-oxide 319.
Personally, the price difference between alkaline and silver oxide batteries is very low and IMHO justifies buying silver-oxide batteries.