have used several different batteries since having the Optimax since (2007)
by far the best has been the Duracell 31 series AGM from Sam's. $179.00
occasionally they put them on sale for $20.00 off!
1000 cranking amps as recommended by Merc.
i run an HDS 12 and a 9 and they suck power.
of course the livewell pumps also when fish are in there.
that's a lot of drain.
had several Tournaments with a dead battery on the others but not this one!!!