Don't know about testing .. just about REAL life.
I have Phonak Audeo YES IX's. Rayovac Mercury Free lasted 3 to 4 days and never gave the full boot-up sequence tones. And I'd have some static from day 1 through to the end.
I bought the Power One 312 batteries from our host. I will never go back to Rayovac! These Power One 312 batteries last from 5 to 6 full days and are FULL power from start to dead. That's pretty good for full feature hearing aids using the iCom all day at work while taking tech support phone calls. I can honestly say that our host provides an excellent web site/forum for hearing impaired people ... and an excellent product and a great price.