Batteries are not the same
The terms cell and battery on a daily basis are often used interchangeably, but the truth is that these are two different technologies. The big difference between them is that the battery loses its electrical charge over time, while the stack. That is, a battery is used or not, retain their electrical charge, which does not happen with a battery.
This is why when you buy a battery pack is noted that these have an expiration date of at least several years. But if after a while you want to use a battery, which can be a device or an electric vehicle, you will not get the slightest trace of electricity, until you reload the battery.
That is why the batteries are considered a generator primary, capable of producing electrical current. The batteries are, however, secondary generators capable of forming a chemical accumulate electric charge. However, batteries have their advantage, and it can be recharged again and again, something that does not happen with the batteries.