What are 18650 battery packs?
18650 battery packs are rechargeable, lithium-based battery packs which use a component cell commonly known in the industry as an 18650 (“eighteen six-fifty”).
This nomenclature is actually a description of the cell itself, based on its dimensions. 18 denotes the approximate diameter of the cell in millimetres. 65 is the length, also in millimetres. The final number is a reference to the fact that for a cylindrical design, there is no third dimension necessary – so it is a zero.
18mm x 65mm x 0mm = 18650!
As hinted at in the title, there are many cell sizes available for a rechargeable battery pack and the most common cylindrical ones are 18650, 21700 and 26650 but there are more. Again, the name of these cells comes from the dimensions – i.e. 21mm diameter, 70mm length and “0” height for a 21700 and 26mm diameter, 65mm length and “0” height for a 26650.
Within these physical cell formats, a variety of chemistries and chemistry variants are found. That chemical mix, together with the details of the internal physical construction determines key performance factors such as:
The total energy that can be stored in the cell (capacity).The maximum discharge rate the cell is capable of.The cycle life, performance in high or low temperature environments and so on.
Usually, there is some trade off between a cell’s various performance features. For example, a cell designed for power tools will typically have the ability to deliver very high currents for a high-power requirement, but the energy density is likely to be lower than a cell optimised for lifetime.
The most common cell chemistries found are lithium nickel manganese cobalt oxide (NMC) or variants thereof and lithium iron phosphate (LFP or LiFePO4).
NMC type cells will be commonly referred to as “lithium ion” an is extremely popular, due to a great balance of energy density and lifetime and cost.
LFP or LiFePO4 (known as lithium iron phosphate) may deliver 10x the cycle life as well as much longer calendar life than NMC, but at the cost of energy density – meaning a bigger and often more expensive battery at the point of purchase. It may be a more cost-effective solution over the product life, however, and is considered a more robust and marginally safe product.
How can we help you with manufacturing 18650 battery packs?
By engaging Alexander Battery Technologies during the early stages of your battery development we fully manage the design elements of your project. We work with your engineers to mitigate risk within the design process and throughout production, leading to a safer, more efficient, and more effective custom battery pack.
A fully customized 18650, 21700 or 26650 battery pack from Alexander Technologies can include numerous design features that improve the overall functionality, efficiency, cost effectiveness, and more. Available design customisations depend on your specific application requirements.
We offer 100% testing for our custom battery packs, verifying and validating performance and quality compliance.
Alexander Battery Technologies continuously strives to manufacture custom battery packs using 18650, 21700 or 26650 cells that are safe, effective, and provide absolute minimal failure rates. We create fully customized packs that provide the custom capabilities that your product requires. We accomplish this by implementing the following design strategies:
Customer specific requirements analysisCell chemistry and power requirements analysisDesign failure mode and effects analysisProcess failure mode and effects analysis
Our custom battery pack designs incorporate maximized performance, and advanced reliability. Our custom packs are manufactured under stringent quality control processes and standards. As an ISO 9001:2015 and ISO 13485:2016 custom battery pack manufacturer, we work with OEMs to ensure all custom BMS meet regulatory requirements.
We also provide Lithium Polymer Battery Packs, NiMH (Nickel Metal Hydride) Battery Packs, and Primary or Non-Rechargeable Battery Packs.
Our design implementation strategies include:
Our 58,000 SqFt, state-of-the-art facility is totally flexible.
The production lines can be re-arranged within a day to increase our efficiency whilst accommodating your requirements.
Our engineers and designers will work closely with you, as almost an extension of your own team to make sure there is a back-and-forth, which will ensure that you are happy with the designs and your requirements are met.