If they say "East Penn" then they are really Deka batteries and the SAME EXACT marine batteries sold at West Marine for often less than HALF the price.
Here is an example:
West Marine sells that SAME EXACT battery, with a different sticker, for 309.00 and they call it the Sea Volt Deep Cycle AGM 105...
And the flooded group 31
Just looked up the current WM pricing vs. my local Sam's Club on the group 31 wet cell.. Holy CRAP!
Remember, these are the SAME EXACT BATTERIES, MADE BY THE SAME MANUFACTURER AND ROLLING OFF THE SAME ASSEMBLY LINE. The ONLY difference is the STICKER...
Sams Club Duracell = Group 29/31 (Deka DC31) 105Ah Battery $84.97
West Marine = Group 31 (Deka DC31) 105Ah Battery $249.99
That is a $165.02 premium to have a West Marine sticker on your battery...
A 315 Ah bank of group 31 flooded batteries:
West Marine = 3 X $249.99 = $749.97
Sam's Club = 3 X $84.97 = $254.91
A 315 Ah bank of group 31 AGM's:
West Marine = 3 X $309.99 = $929.97
Sam's Club = 3 X $166.32 = $498.96