They seem to get it right every single time in the Note series, and apparently the A series phones are also going the right direction in battery capapcity, the A5 got a 74h Endurance score on GSMArena.
I am a fan of Samsung products as I feel they kept Android on the map and proved how powerful of an OS it is with their products, they seemed to set the benchmark every year but the S6 I'm afraid may not do that, the American tech sites are going to tare this phone apart for 1. looking like a iPhone6, 2. Removing features that the iPhone didn't have, 3. Poor battery life. Phones like the LG G2, Note 3, S5, Xperia Z3, iPhone 6 Plus, Note 4 etc...have set quite a high standard in battery life, the S6 will be a shocker, even being beaten by the Nexus 6, and generally Nexus phones show very average to below average battery life.