The 18650 lithium-ion cell is one of the most common lithium-ion cells on the market. Chris Greene takes a closer look.
The Micro-mobility or E-mobility industry has been receiving a lot of publicity over the past few years—and for all the wrong reasons. Through the media, online videos, and direct experience, we have all been witness to the increasing frequency of fires involving E-bikes/scooters. This phenomenon has drawn a lot of attention to this industry, and deservedly so, but it is important to understand the underlying energy source—the 18650 lithium-ion cell. It is the workhorse of the E-mobility, power tool, and portable power supply industry and one of the most common lithium-ion cells on the market. It is small enough to power an E-cigarette/vape cartridge, easily fitting into your pocket, or can be strung together to power much larger items that have become commonplace in the American home.
This cylindrical battery, which derives its name from its dimension—18mm diameter by 65mm in length—was developed in 1994 in response to an increasing demand for smaller and more powerful portable battery-operated devices. The 18650 cell offered a small/compact lightweight rechargeable energy source with high battery voltage—3.2v to 4.2v. The battery had an added benefit of being modular, making it appealing to a variety of rechargeable handheld products as well as larger stationary storage uses.
The 18650 is often compared to an AA battery because of the cylindrical similarities, but this is where the similarities end. The 18650 is larger in size than the AA battery, and its voltage is more than double. The energy density is four-plus times greater than that of an AA battery, but the real difference is in how long this battery can power a device and how fast it can offload its power when needed. This combination of longer-duration use and high cycle life coupled with its ability to offer high-output demands is rare. The 18650 fits into a category of batteries often described as “high drain” and is suited to portable devices that required constant higher voltage such as E-cigarettes, laptop computers, and power tools.
Article written on fireengineering.com, by Chris Greene