Just a point of information. We took ownership of Maxine in late 2007. She came with 3 4d Deka Gel batts and a group 31 Gel start battery. We will need to replace them in the Spring after 11 years of service. We treated them well. Kept them charged up while cruising and never left them plugged in at the dock keeping ice cubes frozen. Just a data point for your information.
Please understand that article only deals with the differences in FLOODED batteries. GEL or AGM are different animals and each has their own pro's & con's. There are also high quality AGM and GEL batteries just like there are high quality flooded batteries. East Penn makes a tremendous deep cycle GEL battery but I would personally only use their AGM product for starting purposes.
As I have mentioned countless times before GEL deep cycle batteries, specifically those made by Easy Penn/Deka (sold under many names) or Sonnenschein Prevailers (Sonnenschein helped set up East Penn/Deka using their manufacturing process) are some of the longest lasting deep cycle batteries you can buy. I have customers that routinely exceed ten years and one customer that went 17 years on his GEL bank. I have a good friend who circled the globe twice, on the same GEL bank, while routinely dipping to 80% DOD. He literally abused the heck out of those batteries yet they took him around the planet twice.
I remember Ted quoted as saying after the Fastnet...."we were eating a steak dinner at the height of the storm...." well found boat well handled.side note: tenacious sailed by ted turner won. kialoa fought hard. you gotta love strong boats. built in sturgeon bay, wis
I'm not sure you meant to say 6v systems. The systems using 6v batteries remain 12v systems by putting two of the 6v batteries in series. If you are using four 6v batteries, you would put two of the 6v batts in series to make a 12v batt, same with the other two, then parallel the two 12v batts to make a 12v bank.
We were in a similar situation. On a trip from Florida to Massachusetts, our two 4D's died at Cape May, NJ. We installed new batteries, but they didn't last very long, nor did several subsequent sets of batteries. Our onboard battery charger tended to overcharge the batts, as did the basic controller for our 135W solar panel. We run the fridge all season long, and anchor out a lot. The 135W panel was ok, but then we bought a Torqeedo outboard for the dinghy, and needed more charging capacity. We upgraded to two 160W panels and a MPPT controller. The new controller charges the batts through the proper stages of charge, and maintains a float charge. No more over charging, and the batts last a lot longer.