Panasonic CR2477

Panasonic CR2477 Overview

The Panasonic CR2477 is a primary (non-rechargeable) 3V lithium coin cell designed for long runtime in compact devices. Its larger height versus other coin cells delivers significantly more capacity, making it a strong fit for smart sensors, key fobs, medical monitors, wearables, and memory backup.

Key Specs

• Size code: CR2477 (24.5 mm diameter × 7.7 mm height)
• Nominal voltage: 3.0 V
• Typical capacity: ~900–1000 mAh (at low drain)
• Chemistry: Lithium Manganese Dioxide (Li/MnO2)
• Operating temperature: roughly -30°C to +85°C, with reduced performance at extremes (check device/datasheet)
• Shelf life: up to 10 years; low self-discharge
• Typical pulse handling: short pulses in the ~10–15 mA range; sustained high current will reduce runtime
• Weight: about 10 g

When to Choose This Battery

• Use if your device explicitly calls for CR2477 and needs long intervals between replacements (e.g., IoT sensors, asset trackers, bike computers).
• Good for intermittent loads with brief radio bursts (BLE/Zigbee) when average current is low and a local capacitor is used.
• Suitable for memory backup (RTC, NVRAM) and low-duty medical/fitness devices requiring stable 3V.

Avoid or Consider Alternatives If

• Your device requires a thinner cell (CR2032 or CR2450). Sizes are not interchangeable.
• You need rechargeable operation—consider LIR2477 (note: higher voltage ~3.6–3.7 V; verify compatibility).
• You need better high-temperature endurance with very low drain—consider BR2477 (lower current capability, different chemistry).
• Your device draws sustained currents above a few mA—use a larger primary cell (e.g., AA/AAA lithium) or an external power source.

Estimated Runtime Examples

Estimates assume ~1000 mAh under low-drain conditions. Real results vary with temperature, pulse load, cut-off voltage, and device design.

Average current	Approx. runtime	Example
10 µA	11+ years (shelf life may limit to ~5–10 years)	RTC/memory backup
0.1 mA	~1.1 years	Low-duty sensor in deep sleep
0.5 mA	~83 days	Frequent sensing/logging
2 mA	~21 days	Always-on indicator/LED

For radios with 10–15 mA transmit bursts, keep the average low (e.g., <0.1 mA) and place a 47–100 µF low-ESR capacitor near the radio to reduce voltage sag.

Compatibility and Fit

• Only use if the device specifies CR2477. The height (7.7 mm) is larger than CR2450 (5.0 mm) and CR2032 (3.2 mm).
• Part numbers may appear as CR2477 or CR-2477. Versions with solder tabs exist for PCB mounting—match the tab layout.
• Polarity: the flat top is positive (+); the case edge/bottom is negative (-). Install as marked in the device.

Performance and Storage Tips

• Store spares cool and dry (15–25°C), in original packaging. Avoid heat and humidity.
• Do not mix old and new cells. Replace all cells in multi-battery devices at the same time.
• Clean contacts and avoid touching the flat surfaces to limit contamination.
• At low temperatures, internal resistance rises; allow the device to warm slightly for best performance.

Safety and Recycling

• Coin cells are a choking and ingestion hazard. Keep out of reach of children and pets.
• Do not recharge, short, puncture, or dispose in fire.
• Recycle at approved battery collection points; do not place in household trash.

Quick Size Comparison

Cell	Size (mm)	Typical capacity	Use case
CR2032	20 × 3.2	~220–240 mAh	Remotes, small wearables
CR2450	24.5 × 5.0	~500–620 mAh	Sensors, larger wearables
CR2477	24.5 × 7.7	~900–1000 mAh	Long-life sensors, key fobs, backup

FAQ

Can I replace a CR2450 or CR2032 with a CR2477?

No. The CR2477 is significantly thicker and will not fit devices designed for thinner cells.

Is the CR2477 rechargeable?

No. It is a primary lithium cell. For rechargeable needs, look for LIR2477 and confirm your device supports the higher voltage and charging.

How long will it last in a sensor?

With a very low average current (≤0.1 mA), 1–3 years is common. Duty cycle, signal strength, and temperature can move this up or down substantially.

What if my device has short high-current pulses?

Use a decoupling capacitor and keep the average current low. If pulses are frequent and long, consider a larger battery format.

Is it safe for medical devices?

Many medical accessories use CR2477 cells for their stable voltage and low self-discharge. Always follow the device maker’s battery recommendations.