How to choose a battery for a watch – caliber, module, and part number

Solar and kinetic watches use special rechargeable cells. Selecting the right battery should not be based solely on its diameter, voltage, or general designation like MT920, MT621, or CTL1616F.

The most important thing is to determine the exact watch mechanism and check what part number has been designated for it.

What information is needed to select a battery?

The most useful are:

• watch brand – e.g., Citizen, Seiko, or Casio,
• mechanism caliber – e.g., Citizen H800, Seiko 5M62,
• module number – especially for Casio watches,
• original battery number – e.g., Citizen 295-753 or Seiko 3023.24X,
• cell symbol – e.g., MT920, MT516, MT621, CTL1616F,
• the appearance and arrangement of contact plates.

Why is the cell symbol not always sufficient?

One of the best examples is MT920. This type of cell appears in many different complete batteries from Citizen and Seiko.

Therefore, you may find several parts based on MT920 that differ in manufacturer number, contact plates, and are intended for different calibers.

Thus, the information:

"The watch has an MT920"

is not always enough to order the correct part.

See: MT920 for the watch – how to choose the right battery?

How to select a battery for Citizen Eco-Drive?

In Citizen Eco-Drive watches, the mechanism caliber and the Citizen part number, usually in the format 295-xxx, are very important.

For example:

• H800 – in our list, it appears with Citizen 295-753,
• H820 – Citizen 295-753,
• G620M – Citizen 295-67 / MT416,
• C601 – Citizen 295-38 / MT920,
• 7810 – Citizen 295-5700 / MT920.

Some calibers appear in listings with more than one part number. You should not automatically assume interchangeability in such cases. You need to check the exact version of the mechanism and the construction of the original battery.

See the full table of Citizen Eco-Drive batteries

How to select a battery for Seiko Kinetic or Seiko Solar?

For Seiko, it is very important to know the mechanism caliber and the full part number, e.g., 3023.24D, 3023.24X, or 3027.26T.

For example:

• V192 – Seiko 3023.24D,
• 5D22 – Seiko 3023.24L,
• 7B22 – Seiko 3023.24M,
• 5J22 – Seiko 3023.24X,
• 5M62 – Seiko 3023.5MZ / 3023.5MY,
• V110 – appears with the Seiko 3027 family.

This is why the designation MT920 alone is not sufficient. Seiko uses many versions of batteries utilizing the same or similar base cell.

See the table of Seiko Kinetic and Solar batteries

How to select a battery for Casio Tough Solar?

In Casio Tough Solar watches, the watch model and module number are very useful.

For example, the popular battery Panasonic CTL1616F is found in many models and modules of Casio, including watches from the GW, GWM, PRG, PRW, MTG, or OCW families.

Other models use CTL920F, CTL1025F, CTL621F, or special batteries like CLB3032.

See the table of Casio Tough Solar batteries

Where to find the watch mechanism designation?

The identification method depends on the manufacturer. Designations can be found on the watch back, on the mechanism itself after opening the case, or in the documentation for a specific model.

If the watch is already disassembled, it is also worth noting the symbol on the old battery and comparing its contact plates.

Caliber, module, and watch model – what are the differences?

Watch model refers to a specific version of the entire watch.

Caliber identifies the mechanism used. One caliber can appear in many different watch models.

In the case of Casio, the term module number is often used to identify the electronics and functions of the watch.

From the perspective of battery selection, identifying the mechanism or module is often more useful than the watch's trade name.

Can you select a battery based on dimensions?

Dimensions can help in identifying parts, but should not be the only criterion.

Two cells may have identical or very similar diameters and heights, yet differ in voltage, construction, or arrangement of contacts.

Is a battery without a plate the same product as one with a plate?

You should not assume they are identical parts. In many watches, plates are part of the connection between the battery and the mechanism, and their shape and position are important for proper assembly.

Therefore, when purchasing, it is worth comparing not only the cell symbol but also the entire appearance of the removed part.

Can a regular battery be used instead of a rechargeable battery?

In a watch designed to work with a battery charged by a solar or kinetic system, the appropriate rechargeable cell intended for that mechanism should be used.

A regular watch battery should not be treated as a substitute for a rechargeable battery just because it has similar dimensions.

What to do if you don't know the watch caliber?

If the mechanism cannot be determined based on the watch designations, the best solution is to identify the old battery or consult a watchmaker.

Helpful information may include:

• a photo of the mechanism designation,
• the symbol on the old cell,
• the watch model and reference number,
• information about the manufacturer,
• the appearance of the contact plates.

Batteries for Citizen, Seiko, and Casio – compatibility tables

We have prepared separate listings for the most popular systems:

• Citizen Eco-Drive Batteries – Compatibility Table
• Seiko Kinetic and Solar Batteries – Compatibility Table
• Casio Tough Solar Batteries – Compatibility Table

Where to buy a battery for a watch?

Kurant watch wholesale offers batteries for Citizen Eco-Drive, Seiko Kinetic, Seiko Solar, Casio Tough Solar, and other mechanisms using rechargeable cells.

For products, we provide designations and compatible calibers and models to facilitate the correct selection of parts.