When i firt got my Northtar, I was only using it as a starting battery, and could not get its resting voltage above 13v, as Northstar states is the full charged OCV.
After one deep cycle and a recharge to full at high amperage it rested at 13.06v forever after when fully charged, and had that extra insane amount of engine cranking grunt which I found shocking.
to get the most from thesse batteries, My experience is a deep cycle and high amp recharge to full to break them in to full potential, and then if deeply cycled again, it really appreciates the high amp recharge. They say 14.46 Vabs at 77F. I use 14.7v and hold it until amps taper to 0.4 or less.
Low and slow solar only recharges, are not so good for these. They need the high amp recharge from a well depleted state every so many cycles, in my experience.
