Renata CR2477N Lithium Coin Battery: Complete Buyer’s Guide, Specs, and Best Practices

When your device needs long, maintenance-free runtime without the bulk of cylindrical cells, the Renata CR2477N stands out. This 3-volt lithium coin battery pairs high capacity with stable voltage delivery, making it a favorite for sensing platforms, asset tracking, medical and wellness devices (non-implant), smart tags, and memory backup. In this guide, you’ll find practical information on sizing, chemistry, performance behavior, safety, storage, selection tips, and deployment best practices—everything you need to integrate the CR2477N with confidence.

Quick Facts

• Type: CR2477N (Lithium coin, Li-MnO₂ chemistry)
• Nominal Voltage: 3.0 V
• Size: Approx. 24.7 mm diameter × 7.7 mm height
• Capacity Class: High, typically in the ~900–1050 mAh range (application-dependent)
• Operating Temperature: Often around −20 °C to +60 °C (verify device/application requirements)
• Key Advantages: Long shelf life, low self-discharge, stable discharge curve, leak-resistant construction
• Typical Uses: Sensors, beacons, trackers, smart buttons, key-type devices, RTC/CMOS backup, medical peripherals

What “CR2477N” Means

Lithium coin cells follow a standardized naming convention:

• CR indicates a lithium manganese dioxide chemistry (Li-MnO₂) primary (non-rechargeable) cell.
• 24 references the diameter family (≈24.7 mm).
• 77 references the height family (≈7.7 mm).
• N is a manufacturer suffix that identifies a specific variant or construction/terminal style from Renata designed to ensure reliable contact in compatible holders and assemblies.

Practically, the CR2477 format gives you a much larger energy reservoir than popular slim coins (for example, CR2032), while preserving the space-saving coin shape. The “N” suffix signals that your device may require this particular variant for proper fit and electrical contact—always check your device’s parts list or holder specification.

Why Choose CR2477N Over Smaller Coin Cells?

The CR2477N’s advantage is capacity. Compared with mid-size coins, it can deliver significantly longer runtime at a similar average current. That margin matters for devices that send periodic radio bursts, run continuous sensing, or must remain field-deployed for months or years. In addition, the larger cathode/anode area and electrolyte volume support a flatter discharge profile, helping electronics that are sensitive to voltage sag.

• Longer intervals between maintenance: Fewer battery swaps reduce total cost of ownership and downtime.
• More stable operation: A flatter discharge curve helps voltage-sensitive logic and RF sections.
• Design flexibility: Additional energy headroom supports longer advertising intervals, more sensor reads, or extra data logging without compromising lifespan.

Common Applications

1) Asset Tracking and Beacons

Low-power radio beacons (BLE, sub-GHz, or proprietary) benefit from the CR2477N’s higher capacity to run longer at a given transmit interval. Designers often pair the cell with a storage capacitor to handle brief transmit current peaks, keeping average draw low and predictable.

2) Industrial and Smart-Home Sensors

Temperature, humidity, door/window, vibration, and leak sensors can idle for long periods and burst into life when reporting. The CR2477N provides the energy buffer needed for multi-year service, especially in environments where replacing a battery is inconvenient.

3) Medical and Wellness Peripherals (Non-Implant)

Glucose loggers, smart thermometers, wearable accessories, and home diagnostics often specify high-reliability coin cells with excellent leakage resistance and predictable voltage. The CR2477N fits well when size constraints favor a flat profile over a cylindrical cell.

4) Memory Backup and RTC

Motherboards, meters, and embedded systems that preserve timestamps and configuration data during mains outages rely on stable, low-drain backup sources. The CR2477N’s low self-discharge makes it a strong candidate for multi-year backup.

5) Smart Buttons and Compact Controllers

For handheld triggers, clickers, and compact controllers that demand long shelf life and instant readiness, the CR2477N offers the right blend of energy density and convenience.

Performance Behavior You Should Know

Voltage Profile

Li-MnO₂ coin cells generally present a stable discharge curve near 3.0 V under light-to-moderate loads. As the cell approaches its end of life, a more rapid voltage drop occurs. Devices that read state of charge via voltage alone should incorporate conservative thresholds or load-based measurements for accuracy.

Load and Pulse Current

Coin cells are designed for low to moderate continuous currents. High pulse demands (e.g., radio TX spikes) can be handled by:

• Using a local storage capacitor to supply the short pulse.
• Staggering radio events to limit consecutive peaks.
• Optimizing firmware duty cycles and sleep intervals.

While the larger CR2477 format tolerates pulses better than thinner coins, a design that routinely demands high continuous current is better served by cylindrical lithium primaries.

Temperature Effects

Lower temperatures increase internal resistance and can reduce usable capacity under load, while higher temperatures can accelerate aging. The CR2477N’s typical operating range is suitable for most indoor and light outdoor applications; for extreme conditions, validate behavior at the edges of your expected temperatures.

Shelf Life and Self-Discharge

A notable benefit of Li-MnO₂ coin cells is a very low self-discharge rate, supporting multi-year shelf life when stored properly. This trait keeps emergency devices and backup systems ready without frequent replacements.

Dimensions, Fit, and the “N” Variant

A standard CR2477 is approximately 24.7 mm in diameter and 7.7 mm in height. The Renata “N” designation identifies a specific variant intended to achieve reliable mechanical and electrical contact in compatible holders or assemblies. Some devices require the “N” style to ensure correct pressure and polarity contact.

• Confirm holder type: If your device calls for CR2477N, using a flat-top CR2477 may not seat or contact correctly.
• Check clearance: The 7.7 mm height is thicker than common coins (e.g., CR2032 at ~3.2 mm). Ensure your enclosure supports the profile.
• Observe polarity: The case is typically the negative terminal; the positive terminal is on the marked side. Follow device markings.

Selecting the CR2477N for a New Design

1. Budget your energy: Sum average current, pulse currents, duty cycle, and desired service life. Add margin for low-temperature operation.
2. Decide reporting cadence: For radios, increase advertising/report intervals to reduce average current substantially.
3. Add pulse support: Use a bypass capacitor near the radio/power rail to handle TX spikes gracefully.
4. Choose the right holder: Select a holder specifically rated for CR2477N to ensure robust contact and retention against vibration.
5. Validate at temperature: Test end-of-life thresholds at your coldest expected temperature to avoid premature dropouts.

Installation Tips

• Power down first: If your device allows, power off before swapping to avoid brownout states that corrupt memory.
• Avoid bending/prying on the cell: Use the intended release tab or holder opening to prevent deformation.
• Clean contacts: Dust or oils reduce contact quality; a brief wipe with a lint-free cloth can help.
• Single-use only: The CR2477N is a primary (non-rechargeable) battery. Do not attempt to recharge.

Storage and Handling

• Store cool and dry: Room temperature, low humidity, and away from direct sunlight.
• Keep in original packaging until use: Protects against shorting and environmental exposure.
• Avoid mixed storage: Don’t store loose coins with metal objects. Short circuits can occur.
• Rotate stock: First-in, first-out practices help ensure the freshest cells reach the field.

Safety Notes

• Child safety: Coin cells present an ingestion hazard. Keep out of reach of children and use secure battery compartments.
• No recharging: Never recharge a lithium primary coin cell.
• Do not incinerate or crush: Physical abuse can cause leakage or rupture.
• Correct orientation: Reversed polarity can damage electronics and the cell.
• End-of-life: Recycle according to local regulations; do not dispose of in fire or household trash where prohibited.

Troubleshooting and FAQs

Q1: Can I substitute a CR2477 for a CR2477N?

Only if your device explicitly allows it. The “N” suffix denotes a Renata variant intended for specific holders/contacts. Using a non-“N” version in a design that expects “N” can cause intermittent contact or failure to power. Always follow the device bill of materials or original specification.

Q2: How long will a CR2477N last?

Runtime depends on load, duty cycle, temperature, and pulse profile. Under light average currents (tens of microamps with brief pulse events), multi-year service is achievable. As average current rises, lifespan decreases. Modeling with realistic load profiles and cold-temperature testing yields the most accurate estimates.

Q3: Is the CR2477N rechargeable?

No. It is a primary lithium manganese dioxide chemistry cell. Never attempt to recharge it. If you need rechargeability with a similar footprint, evaluate rechargeable lithium coin chemistries specifically designed for charging and use charge-management ICs that match that chemistry.

Q4: My device has short transmit bursts and sometimes resets—why?

High instantaneous current may cause transient voltage dip. Add a local storage capacitor near the radio or power rail, optimize firmware to reduce back-to-back bursts, or widen transmit intervals. Ensure your holder and contacts have low resistance and maintain firm pressure on the terminals.

Q5: How should I dispose of used coin cells?

Recycle them through approved collection points. Many local waste authorities, electronics retailers, or municipal depots offer battery recycling programs. Do not incinerate or discard where prohibited.

Specification Snapshot (Typical)

Chemistry	Lithium Manganese Dioxide (Li-MnO₂), primary
Nominal Voltage	3.0 V
Size	Approx. 24.7 mm (D) × 7.7 mm (H)
Capacity Class	High (commonly ~900–1050 mAh, application-dependent)
Operating Temperature	Typically around −20 °C to +60 °C (verify for your device)
Shelf Life	Multi-year under proper storage (low self-discharge)
Self-Discharge	Low (advantageous for backup and long-interval use)
Leak-Resistant Design	Yes—constructed for reliability in qualified holders
Variant	“N” style for compatible holders/contacts (confirm fit)
Typical Use Cases	Sensors, trackers, medical peripherals (non-implant), RTC/CMOS backup, smart buttons

Design Checklist for Engineers and Integrators

• Confirm variant: If the BOM specifies CR2477N, do not substitute another top style without testing.
• Voltage thresholds: Set conservative brownout/reset levels appropriate for 3.0 V primaries.
• Power decoupling: Place bulk capacitance near radio/MCU to tame transient dips.
• Contact resistance: Choose a quality holder; consider vibration and shock loads in the application.
• Thermal validation: Verify performance at the coldest/hottest extremes you expect.
• Service plan: Model life based on real duty cycles; schedule preventive maintenance before end-of-life cliff.

When a Different Format Might Be Better

If your application needs sustained high current (e.g., powerful LEDs, motors, or frequent high-power radio bursts), a cylindrical primary lithium cell or a rechargeable solution with a suitable power budget may be a better fit. The CR2477N excels in low-average-current scenarios where compact size and long life are paramount.

Battery Care in the Field

• Environment: Avoid prolonged exposure to heat, which accelerates aging.
• Sealing: Ensure enclosures prevent moisture ingress that could affect contacts.
• Inspection: During periodic service, check for dust, oxidation, or deformation of the holder.
• Record-keeping: Track installation dates and expected replacement windows for fleet devices.

Summary

The Renata CR2477N combines high capacity, stable 3 V output, low self-discharge, and a contact-reliable variant style that fits devices designed for it. For low-average-current electronics that must run for months or years on a single cell, it offers an excellent balance of energy density and reliability, especially when paired with good holder selection, sensible firmware power management, and proper storage practices. Confirm the “N” variant fit for your device, validate performance at your temperature extremes, and you’ll have a compact power source you can count on.