Interestingly, in my Alta2 aids Duracell lasted about half a day longer than Kirkland Signature; but in my Opn aids with their higher power demand of streaming the Kirklands actually last longer. It must be something about the power curve on the two batteries. In my Alta2’s I got about 6.5-7.5 days with KS and 7-8 with Duracell; in my Opn’s, I get 3-4 days with KS and sometimes as little as 2 with Duracell.
To me the worst problem of shorter battery life is going dead often and in situations where it is inconvenient. Especially since you are supposed to let them charge for a minute or two before you put them in your hearing aid.
When I used disposables, I would try to stagger them so they both didn’t go belly-up on the same day.
I’m still having problems with rechargeables, and since a hurricane is aiming towards us, my appointment with my audiologist has been postponed. 
The newer hearing aids work better, at the cost of shorter battery life. Everything has its price 
Bob
I found I got just about exactly 8 days with Duracell 13 size batteries and 7 with any other brand. I notice that the Duracells that I get here in Canada are made in Germany (my guess is they are made by Varta in Ellwangen Germany).
Gramps, somewhere I think I read that the Duracells we get are made by PowerOne? They are a German company and the brand that I use. Great battery life so far.
Editing because autocorrect changed Gramps to Tramps?!?!