Size names as a shorthand
Cylindrical battery sizes are known by number names: 10440, 14500, 16340, 18650, 21700, 26650 and others. Those names let buyers, suppliers and warehouses refer to the same physical object without a long description, and learning them is the first step in buying cylindrical batteries with confidence. The names are a shorthand for size, and this article treats them strictly as that: a way to name a size, not a specification and not a performance claim.
The shorthand works only when it is used precisely. A size name misread by one digit can name a different size, and an order placed on a misread name will arrive in the wrong size. Buyers should therefore quote size names carefully in enquiries, double-check them against the device compartment or the battery being replaced, and ask the supplier to confirm the size for the exact title.
Small cylindrical sizes
Small cylindrical sizes include 10440, 14430, 14500, 14650, 16340, 18350 and 18500. They serve compact devices where a full-size cylindrical cell will not fit: small torches, compact equipment and devices designed around a small cell. Their small size makes precise naming especially important, because neighbouring sizes differ by only a few millimetres and a misreading is easy.
The 14500 size deserves a note because it appears in several families on this site: the 3.7V family, the 3.2V family and the USB family. A 14500 enquiry should therefore name the family as well as the size, and should confirm the charging route where a USB title is concerned. Size alone is not enough for 14500; size plus family is the minimum for a usable enquiry.
18650: the mid-size workhorse
The 18650 size is the most listed cylindrical size on the company website, and the most widely used cylindrical size in general buying. It appears in the 3.7V family and in the cylindrical USB rechargeable family, and its titles span a range of published wordings. That breadth is useful for a buyer who needs 18650 in quantity, but it also means that 18650 titles must be compared by their exact published wording and confirmed specification, not treated as identical because they share a size name.
A 18650 buyer should ask about the charging route as well as the size: some 18650 titles carry USB wording, which changes how the battery is charged, while others rely on an external charger. Please confirm the route, the full specification, the quantity terms and the lead time for the exact title, and please confirm charger compatibility where a charger is ordered alongside.
21700 and 26650: larger cylindrical sizes
The 21700 size is a larger cylindrical size than 18650, listed on the company website in the 3.7V family. The 26650 size is wider again, listed in the 3.7V family and in the USB family. Larger sizes suit equipment designed around a larger cell, and they must not be ordered as substitutes for smaller sizes: a compartment built for 18650 will not accept 21700 or 26650, and a charger built for one size must be confirmed for another before it is used.
Because the larger-size ranges on this site are narrower than the 18650 range, buyers who need larger sizes should enquire early and confirm availability, quantity terms and lead time for the exact title. A narrow range is not a reason to substitute a different size; it is a reason to confirm the correct size sooner rather than later.
Why sizes never substitute for one another
Cylindrical sizes never substitute for one another on the basis of a name or a title. Physical fit, charger fit and family fit must all match, and a size that fails any one of those three is not a candidate. That rule sounds strict, but it is the rule that prevents the most expensive cylindrical buying error: an order of the wrong size, discovered only when the batteries do not fit the device or the charger.
Where a device can genuinely accept more than one size, that fact should come from the device documentation or from the supplier's written confirmation, not from an assumption. Please state the substitution being considered in the enquiry and ask the supplier to confirm or rule it out explicitly. A written ruling is the only safe basis for a substitution.
Reading a cylindrical listing title
A cylindrical listing title on this site contains the size name and sometimes additional wording: a family indication, a charging-route word or a figure. Each element should be read as title wording, not as a specification. A figure inside a title is not a confirmed capacity or a confirmed performance figure, and this site never turns title wording into a specification table.
The correct response to a title is an enquiry that quotes it exactly and asks for the specification behind it. That enquiry should also state the device, the charger in use and the quantity range, so that the supplier's confirmation answers the actual buying situation rather than a generic product description.
A cylindrical buying routine
A reliable cylindrical buying routine has five steps. First, confirm the size from the device compartment or the battery being replaced. Second, confirm the family: 3.7V, 3.2V, USB or another family present on the site. Third, confirm the charging route and the charger. Fourth, quote the exact listing title and ask for the full specification, quantity terms and lead time. Fifth, keep the supplier's written confirmation with the order record.
That routine works for every cylindrical size, from the smallest to the largest, and it scales from a single battery to a warehouse order. Its value is that it replaces guessing with confirmation at each step, and confirmation is the only protection against the size, family and charger errors that dominate cylindrical buying mistakes.
Putting this guide to use
A guide is only useful when it changes the next enquiry, so finish by turning what you have read into a shortlist. Write down the size family, the chemistry family and the charging route that fit your device, and then find the category page on this site that matches those three answers. From that page, pick the listing titles whose published wording matches your shortlist, and write those titles down exactly as published, without shortening or rewording them. A shortlist built that way can be checked by the supplier title by title, whereas a shortlist built from memory or from a photograph cannot.
Then write the enquiry itself, and keep it specific. State the device or scene, the size and family, the titles under consideration and the quantity range, and ask the supplier to confirm the full specification, the quantity terms and the lead time for each title before payment. If a certificate document is required for the market where the product will be sold, name it in the same message. Keep the supplier's written answers with the order record, and use them as the reference for any repeat order, so that the next purchase starts from confirmed facts rather than from a fresh round of guessing.
What to send with your enquiry
To get a useful answer first time, please include the following in your message. Every item on this list is a question for the supplier to confirm, not a claim made on this page.
- The battery size family you need (for example AA, AAA, 18650, 21700 or 26650) and the listing title exactly as published on this site.
- Your quantity range, so the supplier can confirm the quantity terms that apply to your order.
- For chargers, the plug style and the battery sizes the charger must serve.
- For fans, where the fan will be used — desk, clip-on, handheld or outdoor — and whether it must run while charging.
- Three questions to ask before you order: please confirm the full specification, please confirm the quantity terms, and please confirm the lead time for this listing.
Contact: Manager: Geely Zhang, telephone +8615975606040, email [email protected].
Planning reference for quantity and lead time
Orders in this trade are commonly discussed in the low thousands of pieces for standard cells, and lead times are commonly measured in weeks once a specification has been agreed. Those are trade planning figures, not this company's published policy: the company's own website does not publish a minimum order quantity or a lead time. Before you place an order, please confirm the quantity terms and the lead time that apply to your listing, in writing, and please do not treat this paragraph as a price or delivery promise.
Prices are not published on this site. Please ask for a quotation against the exact listing title, and please confirm the specification, the quantity terms and the lead time before payment.