Technical notes

How to read the numbers, and what they do not tell you.

The technical notes explain how to work with the values on a data sheet rather than just quoting them: which impedance figure is comparable between two brands and which is not, what a cycle-life claim hides about test conditions, and how much spread you can accept between cells that will be welded into the same pack.

These articles are the working counterpart to the guides — narrower, and usually built around a table you can take away. Where a number is used as an example, it is one we hold a manufacturer document for, with the measurement condition stated next to it.