Batteries that last lasting

This AA battery pack contains 12 batteries Duracell. The batteries have a voltage that discharge slowly over the batteries "noname" (easily checked with a multimeter).
These batteries are manufactured with a small marker that shows whether the battery is empty or not, it is not new that system have originated in France in the early 90s and returned occasionally on certain brands and range of battery.

By cons there is a simple trick (and without using a multimeter) to determine if a battery is full or empty: Take a stack holding the upright and made it fall 10 cm straight onto a table ( or any hard surface), if the battery is full it will fall suddenly and stay straight. If the battery is empty it will bounce multiple times on the surface or made you fall so she will not stay straight ...
This is due to a simple chemical reaction, when the battery is discharging manganese dioxide battery which consists turns into manganese oxide. The latter passes from one atom form as "gel" to a state form of particles that can be compared to sand or dust inside the big stack. And when the battery is full the gel absorbs the shock (and thus the battery falls without bouncing), once discharged particles "sands" not cashing the shock wave, and therefore the battery bounces.