Changes
/* Batteries */
* C rating : the higher, the higher current you can draw http://www.rcheliwiki.com/C_rating
** C*Capacity in Ah=Current
** 20Current: 20C *2.22Ah =44A** Power: 44A * 11.1V = 488.4W
* S is the number of cells, and is representing the tension (1S=3.7V, 2S=7.4, 3S=11.1V, ...)
* Balancing: Cells need to be a the same charge level so we can avoid overcharging.
