18650 cells and packs: the standard cylindrical format
The 18650 is a standard cylindrical cell format — 18 mm across and about 65 mm long — and packs built from it suit devices designed around rigid cells: tools, garden equipment, light electric vehicles and general industrial devices.
Layered pack cross-section — the site's recurring diagram motif. It is a schematic, not a photograph of a product, factory or customer project, and it is not presented as a photograph of this company's factory.
Home / Products
Standard format is the 18650's main advantage. Because the cell size is fixed, a device designer can plan the enclosure, the holder and the wiring around a known cylinder, and a pack builder can arrange cells in series for voltage and in parallel for capacity without inventing a new cell. The detail cell on this site illustrates the format exactly: 3.7V nominal, 3000mAh, 4.2V maximum charge voltage, 2.75V discharge cut-off, 65.5 mm high and 18.4 mm in diameter, 48 g, with an 800-cycle life as listed. Those are that cell's figures, and other 18650 cells in the wider range differ in capacity and cycle life.
Packs built from 18650 cells multiply the single cell. A 48V pack, for example, needs 13 cells in series, and parallel strings multiply capacity; the detail pack on this site is a 48V 15Ah pack, 4.6 kg, with a 30A maximum continuous discharge current and a 500-cycle life as listed, for electric bikes and e-scooters among other uses. The series count sets the voltage, the parallel count sets the capacity, and the protection board sets what happens on overcharge, over-discharge, over-current and short circuit. A pack inquiry should therefore state voltage, capacity and peak current together, not voltage alone.
Two cautions apply to 18650 buying. First, capacity figures are only comparable when the discharge conditions match: a cell rated at a low discharge current will deliver less usable capacity at a high current, so compare listings on the same basis or ask for the test conditions. Second, the cell and the pack are different purchases. A bare cell needs a holder, wiring and protection designed by the buyer; a finished pack includes those, and its price and terms reflect that. Buying bare cells to save money and then improvising protection is a false economy that this site does not recommend.
Bulk buying is the natural mode for 18650 cells, since devices and packs consume them by the dozen or hundred. Quantity bands, rather than single-cell prices, are the right subject for a bulk inquiry, and the inquiry should still name the exact cell — voltage, capacity and dimensions — because 18650 cells with the same format differ in capacity, discharge current and cycle life.
How to choose in this family
Fix the chemistry first, then the voltage and series count, then the capacity. Check the exact model listing for its own dimensions, protection, certificate set, minimum order and lead time — those values belong to that listing and do not transfer to other models. If no listed size fits your enclosure, the custom route covers custom dimensions and configurations; describe the enclosure and the electrical requirements rather than asking for a general price.
Related pages
18650 3000mAh cell · 48V 15Ah pack · 18650 basics · 14.8V garden pack
How to place an inquiry, step by step
- Send the device facts. Tell us the device type, the available space (length, width and maximum thickness), the nominal voltage you need, the capacity or runtime you target, and the peak current if your device has motors, radios or heaters.
- Name the model or the chemistry. If a page on this site matches, quote its model description and listing details. If nothing matches, say so and describe the chemistry and voltage you need, so the conversation starts on the custom route.
- Confirm documents and terms in writing. Ask for the certificate set for that exact model, confirm the minimum order, the price basis and the lead time for that listing, and confirm payment and warranty terms before you pay. Terms stated for one model listing do not transfer to another model.
- Agree the sample step. Confirm whether the next step is a listed sample, an engineering sample for a custom design, or a small trial order, and what test you will run on arrival — fit in the enclosure, runtime, or peak-current behaviour.
Send all of this in one message through the contact page: device type, space, voltage, capacity, peak current, model description if you have one, and the documents you need. That is the whole inquiry — no separate form, no account, no extra step.
What to send us now
Send one message with your device type, the space the pack must fit, the voltage and capacity you need, the peak current if it matters, and the model description if a page on this site already matches. Add the documents you need — certificates are available upon request — and whether you need a listed model or a custom design. Use the contact page or write to [email protected], or call +86-755-25629920. A specific message like that is what turns a range of hundreds of models into a short, answerable question.