Timex lists a battery for each of its watch user guides by model number, and its repair form says that number is on the case back: three characters after an M, such as M921.
The battery it takes
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Reading the case back
The model number is short: an M followed by three digits, letters or a mix. Other marks on the case back, such as the water resistance, aren’t the model.
Timex’s W33 guide adds that the battery type is printed on the case back as well, so a watch whose model isn’t in the list may still tell you its cell.
The batteries Timex lists most
| Battery | Models | Example user guides |
|---|---|---|
| CR2016 | 35 | 3-Hand Quartz Analog with Date, 3-Hand Quartz Analog with Day/Date and Atlantis Digital, others |
| CR2025 | 21 | Classic Digital, Command Encounter Digital and Digital Chrono Alarm Timer, others |
| SR626SW | 19 | 2-Hand Quartz Analog, 3-Hand Quartz Analog and Expedition Digital Compass, others |
| CR2032 | 17 | Digital Activity & Step Tracker, Digital Day/Date and Expedition Grid Shock and Command, others |
| SR920SW | 14 | Chronograph with Sub-dials at 6 9 12 and Date, Chronograph with Sub-dials at 6 9 12 and Date at 4 and Full-Size 3-Hand Quartz Analog with Date, others |
| SR621SW | 10 | Men’s Quartz Analog Date, Quartz Analog 2-Hand Reissue and Quartz Analog Moonphase, others |
| Automatic, no battery | 8 | Atelier GMT Automatic Self-Winding and Automatic Self-Winding |
| CR1216 | 4 | Women’s 3-Hand Quartz Analog and Women’s 3-Hand Quartz Analog with Date |
| Solar powered | 4 | Expedition Solar Digital and Solar Powered |
| SR927SW | 4 | Chronograph with Sub-dials at 3 6 9 and Date at 5, Men’s 3-Hand Quartz Analog Day/Date and Men’s Multi-Function Quartz Analog, others |
| Built-in rechargeable | 3 | iConnect Active+, iConnect Premium Active Smart Watch and Metropolitan R |
| SR521SW | 3 | Mini T80 Digital and Small 3-Hand Quartz Analog |
| SR936SW | 3 | Chronograph with Sub-dials at 2 6 10 and Date at 5, Chronograph with Sub-dials at 3 9 and Date and Chronograph with Sub-dials at 6 9 12 and Date at 3 |
| CR1620 | 1 | Marathon Mid-Size Digital |
| CR2012 | 1 | Men’s Full-Size Quartz Analog |
| CR2025 and SR626SW together | 1 | DGTL and UFC Combat |
| SR516SW | 1 | Small 2-Hand Quartz Analog |
| SR616SW | 1 | Women’s Transcend 2-Hand Quartz Analog |
| SR721SW | 1 | Quartz Analog Moonphase Date |
| SR916SW | 1 | Chronograph with Sub-dials at 3 9 |
Counted from the model numbers on Timex’s manuals page.
Same watch name, different cells
Timex’s Ironman guides alone list CR2016, CR2025 and CR2032, depending on the model, so go by the M number rather than the name on the dial.
Who should open it
In the W33 guide, Timex strongly recommends having a retailer or jeweler fit the new battery, and notes that battery life depends on how the watch is used.
If a child swallows a button battery
The National Capital Poison Center says that if anyone swallows a battery, immediately call the 24-hour National Battery Ingestion Hotline at 1-800-498-8666 or your poison center at 1-800-222-1222. Don’t delay. Immediate treatment decreases severity.