Flooded,AGM or Gel deep cycle batteries 12volt

I just got off the phone with the tech department at Parallax. He explained to me in great easy to understand detail what to do in my present situation.

I plan on upgrading my charger/converter to one that has temperature control that monitors the battery temperature and adjusts the charge accordingly.

It also features a boost mode if the battery requires it. I will then purchase 2 AGM batteries and be done with it.