Nucleus 5 uses 2x size 675's or rechargables
Freedoms uses 3x size 675's or rechargables
Med-El uses 3x size 675's not sure if they use rechargables
Advanced Bionics only uses rechargeables.
no, I have freedom (upgraded from Esprit 3G), it takes 3 675
unless they make it differently in other countries which I doubt it. size 13 is more for less powerful hearing aids. My first digital hearing aid was a size 13 (the one that didn't work out so great for me).
My MED-EL uses 3x #675 disposable batteries and has the optional DaCapo Rechargeable Batteries and Charging System that includes 3 batteries. They each last twelve hours on a single charge if you use the high settings with the OPUS 3 Processor.