AG1 Button Cell: Micro Power in a Tiny Space

AG1 Battery Introduction

The AG1 battery, also marked LR621 or LR60, is a widely used alkaline button cell. Many people call it watch battery. There is an equivalent silver oxide model SR621SW (364) with identical outer dimensions, but different chemistry and performance. It is easy to mix them up during replacement.

Basic Specifications

- Size: Diameter 6.8 mm, thickness 2.1 mm, weight approx. 0.28–0.3 g

- Alkaline AG1 (LR621): Nominal voltage 1.5 V, typical capacity 13–18 mAh

- Silver oxide SR621SW (364): Nominal voltage 1.55 V, flatter voltage curve and longer service life

- Type: Non-rechargeable primary battery

- Shelf life: About 2 years under normal sealed storage at room temperature

- Environmental standard: Mercury-free & cadmium-free, compliant with RoHS

Quick tip: They fit the same battery compartment. Silver oxide SR621SW (364) is preferred for precision quartz watches. Cost-effective alkaline AG1 is suitable for LED toys and decorative lights.

Structure & Working Principle

AG1 is an alkaline zinc-manganese dioxide button cell. It consists of zinc anode, manganese dioxide cathode, alkaline electrolyte, separator and sealed steel can. During discharge, zinc is oxidized and manganese dioxide is reduced to supply low continuous current. It is designed for low-current and intermittent discharge, and cannot sustain heavy load.

Silver oxide cells use silver oxide as cathode material. Their discharge voltage stays nearly constant until nearly exhausted, which is the key reason they are chosen for high-precision timekeeping devices.

Typical Applications

AG1 is made for tiny low-power electronics:

1. Quartz watches and fashion watches

2. Mini LED jewelry, glowing earrings and small light-up toys

3. Mini calculators, auxiliary hearing accessories, simple digital thermometers

4. Tiny remote controls, optical sensors and small electronic accessories

5. Electronic gifts and decorative lights

Replacement & Buying Notes

1. Cross reference: AG1 = LR621 = LR60. Same size silver oxide type: SR621SW / 364. AG1 cannot replace AG3, AG4 or AG10. Wrong size causes poor contact or damage to the device.

2. Do not mix old and new batteries, or batteries of different chemistries and brands. Mixing may lead to leakage and heat generation.

3. Check the instruction manual of your watch movement before replacement. Alkaline AG1 is enough for common toys.

4. Store in cool and dry place. Keep away from coins, keys and other metal items to avoid short circuit.

Safety Instructions

1. Do not recharge: AG1 is a primary battery. Recharging may cause swelling, leakage or rupture.

2. High ingestion risk: The small size makes it easy for kids and pets to swallow. Once stuck in the esophagus, the battery will generate chemical burns rapidly. Keep out of reach of children. Seek medical help immediately if swallowed, DO NOT induce vomiting.

3. Do not disassemble, puncture, crush or dispose of in fire. Stop using immediately if the battery leaks or swells. Avoid electrolyte contact with skin and eyes.

4. Install with correct polarity. Reverse installation leads to failure and increases leakage risk over time.

5. Dispose of waste batteries according to local recycling regulations. Do not throw them into general trash.

AG1 vs SR621SW (364)

- AG1 (Alkaline LR621): Lower cost, voltage gradually drops during discharge. Best for toys and decorations without strict voltage requirements.

- SR621SW (Silver Oxide 364): Higher price, stable voltage and longer runtime. Ideal for quartz watches and precision timing products.

Summary

Tiny AG1 button cells are reliable power sources for countless micro electronic products. They are engineered to deliver steady micro current in limited space. Distinguish alkaline and silver oxide versions and follow storage & safety rules for reliable performance.