370, 371, LR69, LR920, LR921, SR69, SR920SW Battery Equivalents and Replacements
LR920 and SR920SW are popular alkaline and silver-oxide batteries commonly found in the wrist and other watches, remote controls, some toys, small flashlights, and similar.
These batteries are usually labeled as SR69, SR920W, SR920SW, SR920PW, SR920, SR921, SR69, 171, 370, 371, LR69, LR920, LR921, SG6, AG6, etc. leading to confusion when proper battery equivalent and replacement battery is needed.
Fortunately, most popular battery brands use SR920SW, 371, 370, LR920, or AG6 when labeling their LR920/SR920SW batteries.
LR920/SR920SW batteries are 9.5 mm in diameter and 2.1 mm in height and they come in two versions: alkaline chemistry and silver-oxide chemistry. Their features and specifications are given in the following table:
|100% SOC Voltage||1.6 V||1.6 V|
|Nominal Voltage||1.5 V||1.55 V|
|Cut-Off Voltage||0.9 V||1.2 V|
|Notes||Voltage significantly drops over time||Voltage is very constant over time|
|Typical Labels||LR69, LR920, LR921, AG6||SR69, SR920W, SR920SW, SR920PW, SR920, SR921, 171, 370, 371, SG6, AG6|
|Typical LR920/SR920SW Capacity||25-30 mAh||40-55 mAh|
Note: Some manufacturers label even silver-oxide batteries as 'AG6' or similar, in order to emphasize that their battery can be used as an alkaline AG6 replacement. The accurate label for the silver-oxide battery is SG6, not AG6.
Alkaline LR69, LR920, LR921, or AG6 batteries have a 100% SOC (State of Charge) voltage of ~1.6 volts, but the nominal voltage is 1.5 volts.
Their cut-off voltage is 0.9 volts and the typical capacity when being slowly drained from 1.5 volts to 0.9 volts is 25-30 mAh.
If alkaline batteries are used in electronic devices that have a cut-off voltage of, for example, 1.2 volts, the use of alkaline batteries in such devices is not recommended due to the very low actual capacity and unreliability of the device itself.
Alkaline LR69/LR920/LR921/AG6 batteries are cheap batteries, with a shelf life of 3-4, even up to 5-6 years, depending on the brand.
When used in devices that support low cut-off voltage, these batteries are also very reliable batteries.
Silver-oxide SR69, SR920W, SR920SW, SR920PW, SR920, SR921, 171, 370, 371, SG6, or AG6 batteries have 100% SOC voltage of 1.6 volts, and a nominal voltage of 1.55 volts.
Their cut-off voltage is 1.2 volts and they feature much more constant voltage during operation than alkaline batteries.
When being slowly drained from 1.55 to 1.2 volts, their typical capacity is 40-55 mAh.
Silver-oxide SR920SW/370/371 batteries are commonly used in wrist watches, small electronic devices, small flashlights, remote controls, and even toys.
Their shelf life is typically 5-10 years, although there are models with a shelf life of just 3 years, but also with 10+ years.
Silver-oxide SR920SW/370/371 batteries do cost slightly more than alkaline LR69/LR920/LR921/AG6 batteries, but they offer larger capacity, more constant voltage and they often have a longer shelf life.
In very low drain devices, the use of silver-oxide batteries is highly recommended - use a good SR920SW battery and forget about it, often for years.
Long Story Short: if you are looking for SR69, SR920W, SR920SW, SR920PW, SR920, SR921, 171, 370, 371, SG6, AG6, LR69, LR920, LR921 battery equivalent and replacement, go for battery labeled SR920SW - it is a silver-oxide battery with nominal voltage of 1.55 volts (also very often printed on the package), stable voltage and good capacity.
If your device used alkaline LR69, LR920, LR921, AG6 battery/batteries, check if it can run using silver-oxide batteries - 0.05 volts difference is often negligible, but check it, just in case.