Renata CR1220 (Lithium Coin)

Overview

The Renata CR1220 is a 3 V lithium coin battery designed for compact devices that need dependable, long-lasting power in a small footprint. Its 12.0 mm diameter and 2.0 mm height make it a common choice for car remotes, fitness trackers, watches, sensors, and memory backup.

At-a-Glance Specs

Chemistry	Lithium Manganese Dioxide (Li‑MnO₂)
Nominal Voltage	3 V
Size	12.0 mm (diameter) × 2.0 mm (height)
Typical Capacity	~35 mAh
Operating Temperature	‑30 °C to +60 °C (‑22 °F to +140 °F)
Compliance	Mercury‑free, RoHS compliant

When to Choose the CR1220

• Use if: your device specifies CR1220; you need a thin coin cell for light to moderate pulse loads (e.g., keyless entry, RTC/memory backup, compact wearables).
• Avoid if: the device calls for BR1220 for higher temperature stability; your device draws sustained high current; or it requires a different thickness (CR1216 = 1.6 mm, CR1225 = 2.5 mm).

Compatibility and Equivalents

Use wherever “CR1220” is specified. Common cross‑references include ECR1220 (Energizer), DL1220 (Duracell), and other brand codes that end in 1220. Do not substitute with CR1216 or CR1225—the diameter matches, but thickness does not and may cause poor contact or damage.

Expected Runtime Examples

• Key fob: intermittent pulses (a few mA for fractions of a second) plus microamp standby can yield roughly 6–18 months, depending on use and temperature.
• Memory backup at 1 µA: up to ~3–4 years under ideal conditions (actual life depends on device cutoff voltage and ambient temperature).
• Small LED gadgets (10 mA draw): typically hours to a few days due to high load relative to capacity.

Real‑world life varies with load profile, device cutoff voltage (often ~2.0 V), temperature, and cell age.

Installation and Handling

1. Verify the device calls for CR1220 and match polarity; the + side usually faces up.
2. Use non‑metal or insulated tweezers to avoid short circuits and surface damage.
3. Clean battery contacts if tarnished; ensure firm contact after closing the compartment.
4. Store spares in original packaging, cool and dry (ideally 10–25 °C), away from metal objects.

Safety and Disposal

• Button/coin cell ingestion hazard: keep away from children and pets. Seek immediate medical attention if swallowed.
• Do not recharge, crush, puncture, or heat above 100 °C. Risk of leakage or rupture.
• When discarding, tape the terminals and recycle according to local battery regulations.

FAQ

Is the CR1220 rechargeable?

No. CR1220 is a primary (non‑rechargeable) lithium coin cell. Use only once and recycle.

What is the difference between CR1220 and BR1220?

Both share the same size. CR (Li‑MnO₂) generally offers higher capacity and better low‑temperature performance; BR (lithium carbon monofluoride) trades some capacity for improved high‑temperature stability and very low self‑discharge for memory backup.

Can I mix brands of CR1220?

Yes, as long as the cell is labeled CR1220 and from a reputable manufacturer. Do not mix old and new cells in the same device.

Why doesn’t my device work after replacement?

Check polarity, contact cleanliness/spring tension, and that you used CR1220 (not CR1216/CR1225). Some devices (e.g., key fobs) may need re‑pairing or a reset after a battery change.