3500mAh
A practical starting point when the device brief prioritizes the 18650 format and the required operating profile does not call for the highest listed capacity.
FEB 18650 / CAPACITY SELECTION
The FEB 18650 platform brings 3500mAh, 3800mAh and 4000mAh options into one practical screening path. For teams comparing lithium ion battery manufacturers, the first decision is not capacity alone: confirm voltage, space and the final device load together.
A battery supplier can review the request more clearly when the capacity target, 18.2*65.1mm cell envelope, application and certification needs are already defined.

Capacity fit at a glance
All three options belong to the same 3.6V 18650 product family. The useful procurement question is which capacity fits the device brief without changing the mechanical envelope or the final system requirements.
A practical starting point when the device brief prioritizes the 18650 format and the required operating profile does not call for the highest listed capacity.
Use this middle option when the design team wants more stored capacity while keeping the same nominal voltage and listed cell dimensions under review.
Consider the highest listed capacity when the device architecture, thermal plan and operating expectations support the additional stored-energy target.
Cell facts and dimensions
Capacity selection becomes meaningful only when the cell can fit the product architecture and the required documentation path.
The product is described as an individual FEB 18650 lithium-ion cell, not as a complete battery pack with assumed electronics or connectors.
| Item | TWE0443 |
|---|---|
| Cell format | 18650 lithium-ion cell |
| Nominal voltage | 3.6V |
| Capacity choices | 3500mAh / 3800mAh / 4000mAh |
| Listed dimensions | 18.2*65.1mm |
| Certifications | CE, RoHS, CB, UN38.3, UL and PSE |
| Warranty | 1 year |
Device-fit checks
Use the same order for every capacity option so the selection stays tied to the finished product rather than a single headline number.
Compare the listed 18.2*65.1mm cell size with the holder, enclosure, contacts and service clearance in the final assembly.
Review how the device is used, charged and stored. Bluetooth speakers, solar lights and smart devices may create different power-design priorities.
List the certifications, packing or shipping documents and product records needed for the destination market before the inquiry is finalized.
Inquiry checkpoint
A short, specific request helps the next conversation focus on fit and documentation instead of filling in basic product details.
Technical reading
These three articles connect the cell specification to power design, device use and the differences between the listed capacity options.

Use voltage and cell format as the first screen before comparing capacity or planning the final assembly.
Read the power-design article
Relate the cell choice to Bluetooth speakers, solar lights and smart devices while keeping final-system validation in view.
Read the device-application article
Review the capacity differences that matter when a device team is narrowing the shortlist.
Read the capacity articleCommon product questions
The FEB 18650 cell is listed in 3500mAh, 3800mAh and 4000mAh capacity options, all with a nominal voltage of 3.6V.
The product is listed at 18.2*65.1mm. Confirm the final assembly clearance and holder design before selecting the capacity.
18650 cells are used in device power designs such as Bluetooth speakers, solar lights and smart devices. Final suitability depends on the complete assembly.
This product is listed with CE, RoHS, CB, UN38.3, UL and PSE certifications.
Share the required capacity, nominal voltage, available cell space, application, quantity and any certification or packing requirements so the supplier can review the request accurately.
The FEB 18650 item is an individual lithium-ion cell. Do not assume a protection board, connector or complete battery pack is included unless the final quotation states it.