Https://www.robotshop.com/ca/en/lithium-ion-batteries-albatross-max.html

Hello @GoldenSand, and welcome to the forum!

This type of battery is inside: https://www.batteryspace.com/prod-specs/NCR18650B.pdf

Because of it’s special production, it has high energy density.

There are 6 cells inside, each giving 3,6V, and they are connected in series, so complete battery is giving 21,6 V.