The grey plastic cased CALB cells are designed for high
current draw, not long cycle life. The Blue ones are better for cycle life, but CALB aren't well known for the product consistency. Sequential
serial numbers will not help in regards to getting a
battery pack that the cells are closely matched. There is a company that actually tests cells and produced closely matched cell groups, but you pay for such precision and the space industry is the main clients.
Far easier to link cells in parallel, the good
parts of one cell will balance out the weaker
parts of another cell in the same parallel cell group. There are two levels the cells must match if you are looking for a closely matched set, internal resistance after 10 cycles and capacity after 10 cycles, no reseller is going to do that for free .... Matched voltage on
delivery is meaningless, you will see this as soon as you start
charging them in series wired set. The
charging current and voltage will be the same across the series string, but you will quickly see the voltage varies and some cells reach 3.6v long before the others.
The practice of linking all the cells in parallel and charging from there does equal out all the cells .... in the initial
installation, they will wander about from that point onwards.
If you want to build your own closely matched parallel set, match the cell that charges to 3.6v with the cell that takes the longest to reach 3.6v, and so on across all the cells available. Then build your battery with series connections of these sets and charge that to 3.8v and watch how close they stay together, you might need to do a bit more switching around, but in the end you will have a battery that will stay in balance for quite some time over a lot of cyxcles and part cycles.
Much easier to build the battery from 4 cells in parallel and link these groups in series, balance charge them to 3.6v, then raise it to 3.8v and you will see they will stay together .... just a matter of averaging out the differences to end up close to the same group numbers across the battery.
As far as incredibly reliable quality cells, hard to go past Winston, but make sure they come in a box with the quality assurance paperwork inside, these are factory A class cells.
T1 Terry