I use Duracell Quantum Alkaline and they last FOREVER!!!!
The one time i tried my Eneloop pro they died prematurely.
Also theres a setting in the menu to choose which type of battery you are using.
But Duracell Quantum i easily get 25 hours.
^ This
Thank you all for the info. I'll note checking the battery type (probably in Detail menu?) and switch to alkaline for the M10 only.
Locking it down.