Beryllium copper is like 50 times as strong as lead. Almost as strong as silicon bronze. That's why Concorde chose it for the terminal posts. It's points like this that won me over. Concorde isn't afraid to state their construction details. Right down to much denser plate paste and a laser guided plate pasting machine. IMHO these folks have all the right answers to all the right questions. I'm a Deka fan as well. I think they make great batteries. But this sort of reminds me of trying to compare a Trojan battery to a Rolls & Surrette battery.
When engineers are allowed to complete their mission of creating an exemplary product the results are usually impressive. It's readily apparent at Concorde battery that engineer's voices carry a long distance. Thank god. One hundred fifteen thousandths thick positive plates made with high density paste is nothing to sneeze at.
The specs of the Duracell/Deka scream hybrid marine use, not true deep cycle. I'd bet that battery has .070" positive plates, ordinary density paste, and no envelope separators. And I HATE lead terminals except for L pad, a tang with a 5/16" hole drilled through it.
