LR621 and SR621SW are very popular coin/button cell batteries often used in wrist watches, small toys, calculators, 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.
Updated: January 11, 2022.
LR621 and SR621 Batteries Features and Specifications
LR621 and SR621 batteries are non-rechargeable button/coin cell batteries featuring physical dimensions of 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, the 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, the device will either shut-off or starts to behave erratically.
The nominal capacity of LR621/LR60/AG1 batteries is around 12-15 mAh when being discharged down to 0.9 volts. Generally, LR621/LR60/AG1 batteries 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.
The nominal voltage of silver-oxide batteries is 1.55 volts and the cut-off voltage is 1.2 volts. When the battery is in use, voltage drops slightly and stays constant during use. As the battery gets fully discharged, voltage drops off sharply and below 1.2 volts, the battery is considered as being fully discharged.
The nominal capacity of SR621, SR621SW, SR60, 164, 364, SG1 batteries is in the 18-23(25) mAh range.
When compared with alkaline batteries, SR621SW batteries, like all coin cell batteries have a larger capacity, more stable/constant operating voltage, higher cut-off voltage, longer shelf life, and are slightly more expensive.
SR621SW Batteries Cross Reference Chart
The following cross reference chart lists some of the most popular SR621SW, LR621, 364/363, AG1 battery models, with their most important features and specifications:
| Battery | Chemistry Nominal and Cutoff Voltages | Capacity Discharge Current | Operating Temperature Annual Self-Discharge Rate |
| Duracell D364 | Silver Oxide 1.55V, 1.2V | 20 mAh 68k1Ω down to 1.2V @20°C 33.2μA @1.52V 68k1Ω @20°C | 0°C to +60°C <10% @20°C |
| Energizer 364/363 | Silver Oxide 1.55V, 1.2V | 19 mAh 68kΩ down to 1.2V @21°C 21μA @1.46V 68kΩ @21°C | - ~2% @20°C |
| Maxell SR621SW | Silver Oxide 1.55V, 1.2V | 18 mAh 47kΩ down to 1.2V @20°C 30μA @1.55V 47kΩ @20°C | -10°C to +60°C - |
| muRata SR621 | Silver Oxide 1.55V, 1.2V | 20 mAh 47kΩ down to 1.2V @23°C 30μA @1.55V 47kΩ @23°C | -10°C to +60°C - |
| Seiko SR621SW | Silver Oxide 1.55V, 1.2V | 23 mAh 30kΩ down to 1.2V @23°C 40μA | -10°C to +60°C - |
| Varta V 364 MF | Silver Oxide 1.55V, 1.2V | 17 mAh 68kΩ down to 1.2V @20°C ~22μA @1.55V 68kΩ @20°C | 0°C to +60°C <10% @20°C |
As one can see, actual performances vary depending on the discharge current/battery load and temperature but also depending on the battery age.
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, the price difference is almost negligible - the use of SR621SW or equivalent silver-oxide batteries is recommended even in kids' toys and similar 'electric' devices.
364, AG1, LR621, SR621SW Batteries Frequently Asked Questions (FAQ)
Here are some of the most common Frequently Asked Questions (FAQ) about 364, AG1, LR621, SR621SW, and other similar batteries:
What battery replaces SR621SW?What watch battery is equivalent to SR621SW?
SR621SW battery is a 1.55V silver-oxide battery featuring physical dimensions of 6.8 x 2.1 mm - any sliver-oxide 1.55V 6.8 x 2.1 mm battery from the reputable brands usually labeled as SR621, SR621W, SR60, 164, 364, SG1, etc. can replace SR621SW in most of the operations.
Also, in emergencies, an alkaline 1.5V 6.8 x 2.1 mm battery can be used to replace the silver-oxide SR621SW battery, but with reduced battery life and possible issues due to the not-so-stable output voltage.
Is 377 battery the same as SR621SW?
No, 377 battery is silver-oxide 6.8 x2.6 mm coin cell battery, while the SR621SW battery is silver-oxide 6.8 x 2.1 mm battery.
What size is the SR621SW battery?
SR621SW battery is a silver-oxide 6.8 x 2.1 mm battery.
Are 377 and 364 batteries interchangeable? Can I use a 364 battery instead of 377?
No, despite they feature the same chemistry (silver-oxide) and very similar dimensions:
- 364: 6.8 x 2.1 mm,
- 377: 6.8 x 2.6 mm.
Due to the same diameter and very similar height, it is possible to place 364 battery into the 377 battery compartment, and sometimes even vice versa.
But, if 364 battery is placed in the 377 battery compartment, contact issues may prevent reliable operation. Also, 364 battery features smaller capacity when compared with 377 battery.
If 377 battery is placed in the battery compartment intended for 364 battery, due to the height differences, there may be some physical damage to the device due to the increased height.
What battery is equivalent to 364?
Any silver-oxide 6.8 x 2.1 mm battery, including SR621, SR621SW, SR60, 164, SG1, etc. batteries from reputable brands.
SR621SW, LR621, 364/363 Batteries Safety Issues
SR621SW, LR621, 364/363 batteries are small and shiny objects that can attract kids and pets - that is why most brands pack them in 'pets-safe' or 'kids-safe' packages.
Although modern SR621SW, LR621, 364/363 batteries don't contain pollutants like mercury or cadmium, when swallowed they can cause chemical burns due to the electrolytic processes - these chemical burns are not as dangerous as when larger batteries with higher capacity and even voltage are swallowed, but nonetheless, IF they get swallowed, immediately contact the nearest emergency center and act according to their instructions.
Better safe than sorry...
Long Story Short: if you need good LR621, LR60, AG1, SR621, SR621SW, SR60, 164, 364, or SG1 battery equivalent, go for a battery labeled as SR621SW (SR621 Silver-Watch) battery - it is a silver-oxide battery with stable voltage and high capacity.
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I possess an in-depth understanding of various battery types, their specifications, applications, and safety considerations. Over time, I've processed vast amounts of data, including technical specifications, user feedback, safety guidelines, and cross-referencing charts related to battery types like LR621 and SR621SW, among others. My expertise encompasses the nuances of battery chemistry, voltage specifications, discharge rates, and the various applications where these batteries are commonly used.
LR621 and SR621SW Batteries: A Comprehensive Overview
Features and Specifications
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Physical Dimensions: Both LR621 and SR621SW batteries have a diameter of 6.8 mm and a height of 2.1 mm.
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Chemistry:
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Alkaline (LR621, LR60, AG1): Nominal voltage of 1.5 volts with a rapid drop in voltage over time. Suitable for devices like toys and flashlights where constant voltage isn't crucial. Nominal capacity is approximately 12-15 mAh.
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Silver-Oxide (SR621, SR621SW, SR60, 164, 364, SG1, AG1): Nominal voltage of 1.55 volts with a more stable operating voltage. The nominal capacity ranges from 18-25 mAh.
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Cross Reference Chart
- This chart provides comparative data for various brands and models of SR621SW and equivalent batteries, including voltage specifications, capacity, discharge current, operating temperature, and annual self-discharge rate.
Applications
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Alkaline Batteries: Typically used in toys, flashlights, and devices where a constant voltage is not essential.
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Silver-Oxide Batteries: Preferred for electronic devices like wristwatches, remote control devices, and remote keys due to their stable voltage output, longer shelf life, and higher capacity compared to alkaline batteries.
Frequently Asked Questions (FAQ)
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Replacement for SR621SW: Any reputable silver-oxide 1.55V 6.8 x 2.1 mm battery can replace SR621SW. In emergencies, an alkaline 1.5V 6.8 x 2.1 mm battery can be used, albeit with reduced battery life.
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377 vs. SR621SW: 377 is a silver-oxide battery with dimensions 6.8 x 2.6 mm, whereas SR621SW has dimensions of 6.8 x 2.1 mm. They are not interchangeable due to size differences.
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364 vs. 377 Interchangeability: Although they have similar chemistry, 364 and 377 batteries are not interchangeable due to slight dimensional differences and potential contact issues.
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Safety Considerations: While modern SR621SW, LR621, and 364/363 batteries are free from pollutants like mercury or cadmium, they can still pose a risk if swallowed. Always store them safely away from children and pets.
Conclusion
For those seeking reliable and high-performance coin/button cell batteries, the SR621SW (Silver-Oxide) stands out for its stable voltage, longer shelf life, and higher capacity. While they may be slightly more expensive than alkaline counterparts, the benefits in terms of performance and reliability often justify the investment.
Note: For the most current pricing and availability, refer to reputable online retailers like Amazon, ensuring that you choose products from trusted brands.
