Primary round battery

The CR2477 is a lithium manganese dioxide (Li-MnO₂) coin cell battery, widely used in low-power electronic devices requiring long-term, reliable energy. Its designation follows the IEC standard:

• "CR": Lithium chemistry (3V nominal voltage).

• "24": Diameter (24.5 mm).

• "77": Thickness (7.7 mm).

Advantages

1. High Energy Density

• Capacity: ~1,000 mAh (varies by brand), offering extended runtime compared to smaller coin cells (e.g., CR2032: 220 mAh).

• Ideal for devices needing years of operation without replacement.

2. Long Shelf Life

• 10+ years of storage with minimal self-discharge (<1% per year), making it suitable for backup or emergency systems.

3. Stable Voltage Output

• Maintains ~3V throughout most of its discharge cycle, critical for precision devices (e.g., medical sensors).

4. Wide Temperature Tolerance

• Operates reliably in -30°C to +60°C, outperforming alkaline batteries in extreme environments.

5. Leak Resistance

• Sealed lithium construction minimizes risk of electrolyte leakage, protecting sensitive electronics.

6. Lightweight and Compact

• Despite its larger size than CR2032/CR2450, it remains portable for wearables and IoT devices.

Disadvantages

1. Non-Rechargeable

• Single-use design contributes to electronic waste and long-term costs for frequent users.

2. Higher Initial Cost

• Unit price: $2\text{–}$5 per cell (vs. $0.50\text{–}$1 for CR2032), though justified by its capacity.

3. Limited High-Current Capability

• Designed for low-drain applications (e.g., <5mA continuous current). Unsuitable for high-power devices like cameras.

4. Environmental Concerns

• Contains lithium, requiring proper disposal/recycling to avoid soil contamination.

5. Size Constraints

• Thicker profile (7.7mm) may not fit ultra-slim devices designed for thinner cells (e.g., CR2025).

Price Analysis

• Retail Price: $2\text{–}$5 per cell (brand-dependent; Panasonic, Energizer, and Duracell are premium options).

• Bulk Discounts: ~$1.50\text{–}$3 per cell when purchasing in volumes (50+ units).

• Cost per mAh: ~$0.002\text{–}$0.005/mAh, more economical than smaller cells (e.g., CR2032: ~$0.004\text{–}$0.010/mAh).

• Long-Term Cost: Higher upfront cost but reduced replacement frequency balances expenses over time.

Primary Applications

1. Consumer Electronics

• Wearables: Fitness trackers, smartwatches (e.g., backup power for timekeeping).

• Remote Controls: High-end remotes requiring multi-year reliability.

2. Medical Devices

• Implantable Devices: Pacemakers (though rare due to regulatory standards).

• Portable Monitors: Glucose meters, thermometers.

3. Industrial & IoT

• Wireless Sensors: Temperature/humidity sensors in smart agriculture.

• Asset Trackers: GPS loggers for shipping containers.

4. Backup Power

• Motherboard BIOS: Retains CMOS settings during power outages.

• Security Systems: Emergency memory backup for alarm panels.

5. Specialty Devices

• Laser Pointers: High-capacity runtime for professional use.

• Electronic Toys: Long-lasting power for interactive gadgets.

Comparison to Alternatives

Conclusion

The CR2477 excels in applications prioritizing longevity and reliability over reusability. While its upfront cost and environmental impact are drawbacks, its high capacity and stability make it indispensable for medical, industrial, and IoT devices. For high-drain or eco-conscious projects, rechargeable Li-ion alternatives (e.g., LIR2477) may be preferable, albeit with tradeoffs in shelf life and energy density.