Seiko 5M62A – Technical Guide

Introduction

The Seiko 5M62A is one of the most widely produced and reliable Kinetic quartz movements, introduced in the early 2000s. It represents a modern evolution of Seiko's Kinetic platform, succeeding earlier calibers like the 5M42A and 5M22A. The 5M62A is known for its long power reserve, efficient energy generation, and robust construction. It features time and date functions, a power reserve indicator, and support for modern MT920 lithium-ion storage cells.

The movement was used across many popular Seiko dive and sport models, including SKA series watches.

Technical Specifications

Functional Overview

Kinetic Charging Mechanism

• Motion of the wrist turns a rotor, which drives a miniature electrical generator.

• Electricity is stored in a rechargeable lithium-ion cell (MT920).

• Power is delivered to a quartz oscillator and step motor, providing high-accuracy timekeeping.

Power Reserve Indicator (PRI)

The 5M62A includes a Power Reserve Indicator, activated via a button at 2 o’clock:

• Seconds hand jumps to indicate power reserve:

  • 5–10 seconds: ~1 day

  • 20 seconds: ~7 days

  • 30 seconds: ~1 month

  • 40+ seconds: Fully charged (~6 months)

If no jump occurs, the cell may be low, failing, or disconnected.

Calendar and Time Setting

• Crown Position 0: Normal

• Crown Position 1: Rotate clockwise to set date

• Crown Position 2: Time setting (seconds hand does not stop)

⚠️ Avoid using the quickset date function between 9 PM and 3 AM, as the date-change mechanism may be engaged.

Reset Procedure (After Battery Replacement)

After replacing the MT920 cell:

1. Ensure secure placement and clean battery contacts.

2. Locate the AC (All Clear) pin contact near the battery.

3. Use non-metallic tweezers to short the AC pin to the positive battery terminal for ~2 seconds.

4. This resets the integrated circuit and step motor driver.

Servicing and Maintenance

Battery / Cell Replacement

Replace only with genuine MT920 or equivalent. Avoid substituting with disposable batteries.

Maintenance Notes

• Clean generator contacts with non-corrosive solvent.

• Avoid static electricity during IC handling.

• No lubrication required unless otherwise specified by Seiko service bulletins.

• Always replace gaskets and pressure test dive models.

Common Issues & Troubleshooting

Compatible Watch Models

The 5M62A was used in a wide range of Seiko Kinetic watches, including:

• Seiko SKA series: SKA371, SKA369, SKA367, etc.

• Seiko Kinetic Diver’s 200M

• Seiko Kinetic Titanium Sport

• Models with unidirectional bezels and screw-down crowns

Look for case backs marked with "5M62-xxxx" for verification.

Summary Table

Conclusion

The Seiko 5M62A is a modern, reliable, and efficient Kinetic quartz movement that offers self-sustaining power with quartz precision. With its improved lithium-ion energy storage, power reserve indicator, and durable rotor design, it remains one of Seiko’s most trusted calibers for sport and diver watches. Proper maintenance—including MT920 replacement every 8–10 years—will keep this movement running smoothly for decades.