Silver oxide batteries are often used in quartz watches because they have excellent performance at small sizes. One of the popular power sources for watches manufactured by Q&Q, Casio, Starion and others is the SR621SW (SR-60) battery.
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SR621SW Battery Specifications
This is a galvanic current source of circular shape (colloquially called a button battery), in which silver oxide is used as the active element. According to the Russian GOST, they are called silver-zinc elements SC-0.015.
Electricity in the SR621SW cells is generated by the chemical substitution reaction of zinc (Zn) and silver oxide (Ag2O) in an alkaline electrolyte (KOH or NaOH), which results in an electromotive force.
The battery has the following options:
- dimensions - diameter 6.8 mm, height 2.15 mm;
- weight - about 0.32 grams;
- rated voltage - 1.55 volts;
- typical capacity - 20-25 mAh (when discharged by a load with a constant resistance of 47 kilo-ohms up to 1.2 v);
- permissible operating temperature - from -10 to +60 degrees;
- Warranty period of storage - up to 10 years;
- self-discharge - less than 5% per year at a storage temperature of 20 degrees.
Analogs of battery SR621SW
There are modifications to the SR621SW batteries marked SR621W. This designation means that they have less power, which is associated with the use of a cheaper electrolyte.
Various manufacturers produce batteries of identical size (alkaline and silver oxide) with their own markings that differ from the international designation SR60 (SC-60).
Silver oxide batteries with the following markings are completely identical: SW621, SR621W, SR621PW, SB-BW, SB-AG / DG, 280-70, 280-34, 364/363, 364 (D364), 364 (31), V364 (531), GP364, T (manufacturer Timex), 602 (Bulova).
They can be replaced with alkaline (alkaline) power sources of the same size, designated LR60, LR621, LR60 / 621, AG1, AG-1, AG1 / 364A, SB-AG, RW320.
Alkaline batteries are cheaper, but their voltage is slightly less - 1.5 volts, they have less electrical capacity (about 13 mAh), weigh a little less (0.28 grams) and are more dangerous in terms of the possibility of electrolyte leakage.
Battery Applications
As a rule, SR621SW current sources are used in quartz watches.
In addition, they are used in the following devices:
- photographic equipment;
- electronic keychains;
- blood glucose meters;
- calculators;
- other miniature electronic devices.
Can the SR621SW be charged
Any batteries cannot be charged or recharged. The industry does not produce batteries of this size. This is due to the relative cheapness of tablet-type batteries, their long life and miniature housing. The electrochemical processes occurring in batteries are irreversible.
If the voltage in it drops below 1.4 volts, then this means that the alkaline electrolyte contained in it began to destroy the internal separator. As a result, the processes of corrosion and gas evolution are accelerated inside the battery, which leads to an increase in internal pressure and, over time, can lead to electrolyte leakage. If an external influence in the form of a charging current is added to this process, then squeezing out the electrolyte mixture from the battery case is almost guaranteed.
Important! If the “recharged” battery is put back into the watch, then over time, due to the breakthrough of alkaline gases, caustic particles settle on the parts of their mechanism, their glass becomes cloudy, which will eventually lead to their breakage.
In this regard, it is not necessary to save a penny on charging disposable batteries and lose tens and hundreds of times a lot of money due to broken watches or other devices affected by leaking alkali.
For the same reason, do not leave a quartz watch in the sun, as this also leads to an increase in pressure inside the battery case.
Popular manufacturers and their features
Many manufacturers produce watch batteries, but silver-zinc products made by Sony, Camelion, Renata, Duracell, Varta, Citizen, Seiko, GP, Rayovac, Panasonic, Maxell, Energizer have the best quality. They are more expensive than analogues, but their characteristics, quality, safety and duration of operation are worth it.
The difference in quality is due to the use of high-quality components and compliance with all the subtleties of the process. For example, in cheaper batteries, sodium hydroxide (NaOH) can be used as an electrolyte, as a result of which the resulting battery will have a lower electric capacity than that which uses potassium hydroxide (KOH).
The physical consistency is also important, as well as what additives are used in the electrolyte. For high-quality manufacturers, it is gel-like and has inclusions of additional substances that reduce gas formation, which makes such batteries safer against leaks.
What to look for when purchasing
When buying watch batteries, you need to pay attention to the following elements:
- shelf life;
- packaging integrity;
- absence of traces of alkali, corrosion, whitish plaque and opacities on the battery case;
- high-quality printing on a blister with no grammatical errors.
Qualitatively selected silver oxide power sources can operate for several years, provided that the electronic devices that they power are protected from overheating and overloads.
