Dollar for dollar I have had good service out of plain old fashioned lead. Most of the time when people have premature failure it is due to not following a "healthy" cycle. You dont let a lead battery go "dead" it damages the plates inside because they corrode without activity. I keep a trickle charger (1.5 amp deal from Harbor freight) mounted inside my battery box so when I get home I stick the powercord to it every time, whether I used the battery or not. I am in starting my 3rd year with my cheapo wallymart troller and it is doing fine running my troller,depth finder and occasionally a spot light. Cant say the same for my starting battery, but I didn't keep a slow charge on it until I had my battery trouble last month, now I do. Always having that fresh charge keep the load off of the charging system on the engine as well and with alot of the older motors like mine the system is a low amperage and somewhat delicate unit.
BACKLASH, I ALSO USE THOSE CHEAP WALLY WORLD BATTERIES ON MY MOTORGUIDE AN HAVE HAD GOOD SERVICE, I ALSO DO AS SUNDROP DOES I KEEP A TRICKLE CHARGE ON MINE AS SOON AS I GET THE BOAT AT THE HOUSE. CHRIS
For the money I'd go with the lead-acid but make sure it is a DEEP Cycle battery not a Cranking battery. The difference in the thickness of the plates. A deep cycle can be discharged to a much lower level than a cranking style without hurting the cells.
The also make a Dual which is really in between a cranking and a deep cycle - it will do either but has a shorter life span (less charge/discharge cycles) than a deep cycle.
This is a tough question adn I am interested as well. I understand the issues needed with Deep Cycle, But after reading reviews on the Optima deep cycle, I thought that would be the answer.
From a practical and not a 'Diamond Jim' capacity. Wally world seems from what I have read to be the best solution and value.
AS with many batteries from Planes to dirt bikes, I also find the trikle charger to be MOST valuable, but Remember it has to be pluggin in to work. Darn I I can remember when I am tired from fishing than cleaning. That the human mind set, or CRS .
I use the triklr chargers from Battery Tender and bought extra pigtails for each battery so I can swap quickly.