A few words about how we check cells before sale...

Even though the cells are already pre-segregated at the supplier, it is only at our workshop that we are able to make sure that everything is under control and that they will work properly and without defects for new customers. Therefore, we first examine the cells in terms of their physical parameters. We eliminate from the further process any items that may have been damaged during transport, e.g. dented.

If the visual inspection does not reveal any problems, we move on to the next, more important step - measuring the impedance and storage voltage ranges. Specialized automatic testers and sorting machines examine each cell with infinite patience and precision, noting its technical parameters and qualifying them for further testing.

We only care about the best parameters and any deviations from the norm are eliminated! :)

The next step is a capacity test. And here we are relieved by the latest technology thanks to the use of large multi-channel load testers. A computer supervising the entire process checks whether the capacity declared by the supplier agrees with reality. And we want to make sure that the cells can be further connected into larger packages without any problems. During research in this step, we always use the manufacturer's documentation regarding the testing of specific models. Ranges of test voltages or measurement currents that are important for the quality of the measurement and the accuracy of the results can be entered into the tester so that it always gives repeatable and reliable results.

Then we rest the tested cells. Warehouse shelves full of boxes of cells, which we give for about 2 weeks to check whether the cells do not have too much self-discharge. The best way to do this is to measure the voltage now and again in a dozen or so days :) Contrary to appearances, this is a very important test! After all, cells are not used immediately, they often have to lie in hobby workshops for many weeks or months before it is time to use them in the next big project. :)

If everything is OK and we have no objections to any of the steps in our own tests, the cells land in a special place, from where they will soon be on their way to new, wonderful projects!