SR721SW/362 Battery Specifications and Safety Issues

The SR721SW/362 battery is a small, non-rechargeable silver oxide button cell, commonly found in watches, micro-devices, remote controls, calculators, and medical instruments. It stands out because of its extended shelf life, superior pulse current tolerance, and a broad operating temperature range. Although similarly sized alkaline batteries are less costly, they generally have a shorter shelf life and lower capacity.

Widely used in devices where dependable performance and longevity are crucial, the SR721SW/362 battery proves its superiority through consistent voltage output and a slow discharge rate, which are critical for powering sensitive electronics accurately. Reports from horologists highlight the significant role of these silver oxide batteries in ensuring the accuracy of timepieces over long durations. Furthermore, medical device manufacturers prefer these batteries for their dependability in crucial applications. While the initial cost may cause some to turn to alkaline alternatives, the long-term reliability and uniform performance of silver oxide batteries is usually worth the higher upfront investment.

Catalog

Characteristics and Specifications of SR721SW/362 Battery

The SR721SW/362 battery has a physical size of 7.9 x 2.1 mm, a nominal voltage of 1.55V, and a cutoff voltage of 1.2V. Its nominal capacity varies from 25 to 30 mAh. An annual self-discharge rate of approximately 5-10% can be observed, depending on the battery model and storage temperature. It operates across a temperature range of 0°C to +60°C, although some models are designed for broader temperature spectrums. The battery is also known by other names, such as SR721, SR721W, SR721PW, SR58, 162, 361, 362, SG11, AG11, and D361/D362.

The SR721 series is further divided into SR721S, which includes a sodium hydroxide electrolyte, and SR721P, which contains a potassium hydroxide electrolyte. The SR721W variant is typically employed in watches. Additionally, certain models are specifically designed for low-drain applications (362 series), while others cater to high-drain scenarios (361 series). Multi-drain batteries are commonly labeled as 361/362.

For comparison, alkaline batteries of the same dimensions (7.9 x 2.1 mm) come with a nominal voltage of 1.5V and a cutoff voltage of 0.9V, with a nominal capacity of 15-25 mAh. Even though they are more budget-friendly, alkaline batteries tend to have reduced voltage stability and shorter shelf lives. As a result, these are often used in micro-LED flashlights, toys, medical instruments, and calculators.

The following comparison chart lists some of the most popular silver-oxide 7.9x2.1mm batteries with their most important features and specifications:

Battery Datasheet	Capacity	Operating Temperature	Annual Self-Discharge Rate	Discharge Current
Duracell D361/D362	24 mAh, 47 kΩ down to 1.2V @20°C	0°C to +60°C	<10% @20°C	44.5 μA, 34k8Ω @20°C (Note: datasheet → 47kΩ?!)
muRata SR721	29 mAh, 30 kΩ down to 1.2V @23°C	-10°C to +60°C	-	50 μA, 30 kΩ @23°C
Renata 361	24 mAh, 34k8Ω down to 1.2V @20°C	-10°C to +60°C	<10% @20°C	44.5 μA, 34k8Ω @20°C
Renata 362	23 mAh, 34k8Ω down to 0.9V @20°C	-10°C to +60°C	<5% @20°C	45 μA, 34k8Ω @20°C

From a practice-centric perspective, the choice of battery type heavily depends on the specific usage requirements. For example, in wristwatches where energy efficiency and longevity are critical, SR721SW/362 batteries are preferred due to their higher capacity and stable voltage output. Conversely, for cost-sensitive applications like toys, where frequent battery replacements are less concerning, the more economical alkaline batteries may be advantageous.

Considering human practical experience, it is important to note that in high-precision devices such as medical instruments, the variable voltage provided by alkaline batteries could lead to inaccuracies or malfunctions. Therefore, the reliability and consistency offered by SR721SW/362 batteries become vitally important. Moreover, in extreme environments with significant temperature fluctuations, the broader operational range of SR721SW/362 batteries ensures consistent performance, essential for both safety and functionality.

SR721SW/362 Battery Safety Issues

Modern SR721SW/362 batteries do not contain heavy metals such as lead, mercury, or cadmium. But why is this shift away from heavy metals significant? It reflects an evolution towards safer and more environmentally friendly alternatives. Despite this progress, proper recycling of these batteries remains mandatory. Consumption of such batteries can result in severe internal burns. If accidental ingestion occurs, contacting an emergency center immediately is imperative. Therefore, storing SR721SW/362 batteries out of the reach of children and pets is crucial.

Does the potential danger stop with ingestion? Certainly not. Practical human experiences emphasize the necessity of employing preventative measures. Parents and pet owners often navigate these concerns by using battery organizers and high shelf storage, keeping batteries securely out of reach. Another preventive measure is educating family members about the risks associated with battery misuse.

Why emphasize education? This approach is bolstered by numerous safety protocols that advocate for secure storage and proper handling. These protocols aim to prevent accidental ingestion or other mishaps.

From an environmental perspective, a shift to non-toxic battery components signifies growing awareness of sustainability and environmental protection. Yet, the end-users bear significant responsibility for recycling these batteries properly to avoid environmental contamination.

What if you need a 7.9x2.1 mm non-rechargeable battery? The silver-oxide SR721SW/362 multi-drain battery stands out. It offers stable output voltage, good capacity, and resistance to surge discharge, paired with a low self-discharge rate. These specifications enhance the longevity and reliability of precision devices. This battery's dependable performance has been demonstrated in various field applications, proving its value for both personal and professional use.