295-5100 MT621 Rechargeable Battery for Citizen Eco-Drive
Product Overview
The 295-5100 MT621 rechargeable battery is a high-performance sealed capacitor engineered exclusively for Citizen Eco-Drive watches. Designed as a direct replacement for original components, this battery restores reliable power and consistent functionality to watches experiencing display issues, irregular movement, or complete power loss—even after full charging. Ideal for both watch repair professionals and watch owners performing DIY maintenance, the MT621 ensures your timepiece returns to optimal operation with minimal downtime. Built to meet stringent performance and safety benchmarks, it supports accurate timekeeping across a range of lighting conditions, from direct sunlight to indoor environments. 
Key Features
- Exact Model Compatibility: Precisely calibrated for Citizen Eco-Drive watches using capacitor models 5700, A100, B110, B117, BP10, E000, E001, E010, E011, E013, E030, E031, E068, E100, E101, E106, E110, E111, E168, E410, G430, G431, G504, G530, H500, H501, H504, H509, H570, H571, and J810. Always verify your watch’s back housing model number before ordering to ensure a correct and safe fit.
- Premium Performance: Constructed with Grade A+ lithium-polymer technology, this sealed capacitor delivers stable voltage output and exceptional energy retention. It maintains up to 98% of its charge after 24 months of storage, allowing your watch to remain functional even after extended periods without exposure to light.
- Certified Safe Design: Fully tested and certified to FCC and CE standards, the MT621 includes built-in safeguards against overcharging, overheating, and short circuits. Its leak-proof construction protects delicate internal watch mechanisms, ensuring long-term reliability and peace of mind during daily wear.
- Optimized Energy Efficiency: Utilizes advanced capacitor technology that efficiently converts both natural sunlight and artificial indoor light into usable energy. This maximizes charging effectiveness across various environments, helping maintain consistent power levels regardless of lighting conditions.
- Reliable Activation & Maintenance: If your watch enters sleep mode due to prolonged darkness, simply place it under strong light for 4–6 hours to reactivate full function. For ongoing battery health, periodic exposure to sunlight (2–3 hours weekly) is recommended to sustain optimal charge levels and prevent deep discharge.
Technical Specifications
- Battery Model: 295-5100 (MT621)
- Type: Rechargeable sealed capacitor
- Chemistry: Lithium-polymer
- Dimensions: Diameter: 6.8 mm, Height: 2.1 mm
- Compatibility: Citizen Eco-Drive watches only
- Certifications: FCC, CE
- Charge Retention: 98% after 24+ months
- Storage Recommendation: Avoid long-term storage in dark environments such as drawers or cases
Benefits & Use Cases
This battery is the ideal solution for restoring full functionality to Citizen Eco-Drive watches that exhibit abnormal behavior—such as erratic timekeeping, failure to move, or operation at one-second intervals despite apparent full charging. It is particularly valuable for users who depend on solar-powered timekeeping and require a dependable, long-lasting power source that aligns with Citizen’s original design standards. Whether you’re replacing a depleted capacitor or performing routine maintenance, the MT621 ensures your watch continues to harness ambient light efficiently and maintain accurate timekeeping. 
For watches that have been stored in dark conditions—such as drawers, boxes, or cases—this battery supports straightforward reactivation with minimal light exposure. Regular maintenance involving periodic sunlight exposure helps preserve peak performance and extends the overall lifespan of both the battery and the timepiece. The included seal protective storage box ensures the battery remains in optimal condition prior to installation, shielding it from environmental contaminants and moisture. 
Important Notes
- Always confirm your watch’s model number (located on the back housing) matches one of the listed compatible models before purchasing.
- Do not store the watch in complete darkness for extended periods, as this may lead to deep discharge and require longer reactivation times.
- Reactivation after prolonged storage requires 4–6 hours under strong light; indoor lighting may require longer exposure depending on intensity and distance from the light source.
- For optimal battery health, expose the watch to sunlight for 2–3 hours weekly, especially if worn infrequently or kept in low-light environments.
- This product includes a seal protective storage box to maintain battery integrity before installation.
- Our customer support team is available to assist with any pre- or post-purchase questions, ensuring a smooth and satisfying experience.
Backed by verified customer feedback averaging between 4.2 and 5.0 stars, users consistently report reliable performance, accurate compatibility, and successful restoration of watch function when installation guidelines are followed. The MT621 battery stands as a trusted, authentic-grade solution for maintaining the precision, sustainability, and innovation that define the Citizen Eco-Drive experience.
