Hey guys,
Let me pass on what I learned from a battery "specialist". Not sure if he really was but this made sense to me. You can decide for yourselves. If I recall, he said there were basically three kinds of batteries.., starting, deep cycle and the hybrids. The basic difference was lead plate thickness. His definitions went something like this.., starting batteries are what you have in your car and "cold cranking amps" are certainly important when it comes to starting your car (or boat). They have relatively thin lead plates and provide plenty of amps for a short time and re-charge rapidly and well. Their down side was they don't provide a lot of amps for very long and don't survive being deeply discharged very well, (as in pot pulling, winch hauling, or long periods of using cabin lights, radios etc.,). You can apparently kill a good starting battery by discharging it too deeply, just a few times.
The opposite end was a true deep cycle battery which has very thick plates, is very heavy, large and expensive. While not a very good starting battery (the reason escapes me at the moment) it excels in providing amps for long periods and accepts being deeply discharged, then recharged with little damage, over and over.
The hybrid is somewhere in between and is what most of us are familiar with. This is the battery that Shucks, Napa, Costco and others all sell as Marine Deep Cycle Batteries. Thicker plates than a starting battery, thinner than a true deep cycle, their performance is also somewhere in the middle.
The statistic I found interesting was (according to this guy) that we could expect somewhere around 1-4 years of life out of these batteries, depending on abuse. Here in Alaska, where cold temps and long hauls on the pot puller are common, I got just barely over a year on my two new batteries from last year. I brought them inside before ice up, charged them a couple of times and kept them off of the floor, but still only got a year out of them.
So for my money I went with the best warranty I could get, in this case Shucks. I bought a 2 year, full replacement battery (pro-rated after that) and will probably have to trade it in every year to year and a half. That's life in the Arctic.
As an aside, his opinion of the gel batteries was great for cars, negative for boats because they didn't survive the deep discharge very well and were so expensive.
Billy