3pcs of Renata 364 SR621SW Swiss Watch Battery 1.55v

Product Overview

Ensure your watch keeps accurate time with this 3-pack of genuine Renata 364 SR621SW Swiss watch batteries. Renata is a trusted name in precision timekeeping, originally founded in Switzerland in 1952 to manufacture mechanical components for wristwatches before transitioning to high-performance silver-oxide batteries in the 1970s. Today, Renata operates a modern, fully automated production facility in Itingen, Switzerland, where research, development, manufacturing, and rigorous quality testing are all conducted under one roof. As a Swatch Group company—alongside renowned brands like Swatch, Tissot, Longines, and Omega—Renata brings decades of expertise to every battery it produces. This specific model delivers reliable 1.55-volt power in a compact coin cell format, ideal for small electronic devices that demand consistent, long-lasting energy.

Developed in cooperation with The Federation of the Swiss Watch Industry, Renata’s silver-oxide batteries are engineered to meet the exacting standards of Swiss timekeeping. Each battery undergoes extensive quality testing throughout production, ensuring uniformity and reliability from the first to the last unit. The 364 SR621SW model is part of Renata’s zero-mercury line, reflecting the company’s commitment to environmental responsibility without compromising performance. With over 50 years of experience powering watches, Renata has become a preferred choice for both consumers and professionals who value precision and durability.

Key Features

• Swiss Precision Engineering – Manufactured by Renata, a Swiss battery specialist with over 50 years of experience in powering watches and precision electronics, ensuring top-tier reliability and performance.
• 100% Mercury-Free – Environmentally responsible design eliminates mercury content, making these batteries safer for disposal and compliant with modern environmental standards.
• Optimized for High and Low Drain Devices – Engineered to deliver stable voltage whether powering high-drain digital functions or low-drain analog movements, maximizing efficiency across various applications.
• Advanced Leak-Proof Sealing Technology – Protects sensitive watch mechanisms from damage by preventing electrolyte leakage, even under temperature fluctuations or extended storage.
• High-Capacity Retention – Maintains charge integrity over time, reducing the need for frequent replacements and ensuring dependable operation when installed.
• Fully Transparent Freshness Dating – Clear expiration date labeling allows users to verify battery age and freshness before installation, promoting optimal performance.
• User-Friendly Packaging – Features a convenient peel-off flap for easy removal and pre-perforated blister packs that separate cleanly, simplifying storage and access.

Technical Specifications

• Model Number: 364 / SR621SW
• Voltage: 1.55 V
• Capacity: 16 mAh
• Diameter: 0.228 inches / 5.8 mm
• Height: 0.083 inches / 2.1 mm
• Battery Chemistry: Silver-Oxide
• Quantity: 3 batteries included
• Manufacturer: Renata (Switzerland)
• ISO Certifications: ISO 9001 and ISO 14001 (certified by Bureau Veritas, Switzerland, December 2020)
• Package Dimensions: 3.8 x 2.75 x 0.06 inches; 0.01 ounces
• ASIN: B00E6XD9KA
• Date First Available: July 27, 2013
• Not Discontinued by Manufacturer

Benefits & Use Cases

These Renata 364 SR621SW batteries are specifically designed for compact electronic devices that require stable, long-term power delivery. They are ideal replacements for wristwatches—especially analog models—where consistent voltage is critical for accurate timekeeping. The silver-oxide chemistry ensures a steady output voltage throughout the battery’s life, unlike alkaline alternatives that gradually decline in power. This stable discharge curve helps maintain precision in timekeeping devices, preventing erratic behavior or premature failure.

Beyond timepieces, these batteries can support a range of small electronics such as calculators, key fobs, medical devices, fitness trackers, and memory backup systems in clocks or small instruments. Their compact size (5.8 mm diameter, 2.1 mm height) makes them suitable for slim-profile devices where space is limited. With a capacity of 16 mAh, they offer extended runtime for low-power applications, reducing maintenance frequency and ensuring your devices remain operational when you need them most.

Important Notes

Always verify compatibility with your device before installation—confirm the model number (364 or SR621SW) and physical dimensions match your original battery. Store unused batteries in a cool, dry place away from metal objects to prevent short-circuiting. Although the packaging is designed for easy separation, handle with care to avoid puncturing the cells. These batteries are not rechargeable. Dispose of used batteries according to local regulations due to their silver content. While the product is not discontinued, availability may vary by retailer. Packaging may differ slightly from images shown but will contain the same high-quality Renata batteries.