There is a date code embedded in the part number of OEM batteries -- such as 1A8  - the 1A for a recent battery would be October 2021.  It's a  three-digit field.

It isn't uncommon for it to take a few discharge-charge cycles for a new battery to reach its design capacity.

If this is a new system (and therefore a new battery), that's almost certainly the case.

If this is a replacement battery, it may or may not be the case depending on the age of the battery -- if it's not brand new (say has been sitting on a shelf for a year or more), you may never see the full design capacity from the battery.

This is a old laptop but I have purchase a new battery for it.   I did compared it with other dell  laptops and in history for the very first day they show both of them equal.  Might be they are shipping me old battery 

Hi Can you explain how the date code works please.

@ejn63​ Hello, do you know how many charge-discharge cycles are necessary to calibrate the battery?

Single digits of charge cycles should reach max capacity.

The date code starts with the year (0 = 2020, 1 = 2021, etc.).  The second digit is the month.  Third is the day.

05L would be May, 2020, etc.