I thought Deka was a a premium deep cycle. Never have used one. In my boat when I was fishing two to three days a week and fishing tournaments every weekend I tried a variety of trolling motor batteries. Trojan had a great rep, but for me started losing capacity after about 11-12 months. The dealer said if they load test at all they are still good so no warranty. Never bought another Trojan. Way to epensive for that shit service life and poor service. I tried a couple brands of deep cycle AGMs and got about 3 yeas use out of them. Once when I was short on cash I bought a set of WalMart Maxx Deep cycles in group 29 size. I got 18 months out of them and a free replacement. They were half the price of the cheapest AGM deep cycles. So I have been using the WalMart group 29 deep cycle Maxx batteries in my boats ever since.
Now trolling motor batteries in a boat see pretty hard use if you fish a lot. They see a significant discharge every time you go out, and then get charged when you get home. I suspect its possible in a lighter use they might last a little longer. I have been using WalMart batteries in my truck and tractor for years now as well. I get better life out of a Walmart tractor battery then I got out of the insanely priced original John Deere battery. The one thing is I always buy the BEST' grade battery WalMart offers rather than the cheapest.
I was hearing great things about Dakota Lithium and was considering biting the bullet on those for my boats (very expensive), but a couple users who have had problems have reported that Dakota Lithium will not respond to them with issues on in warranty batteries. I'm not sure I want to gamble the price of lithiums just yet. Not even the price of "cheaper" Chinese lithium batteries on Ebay, Alibaba, or Amazon.
Thanks. It appears that Johnson Controls makes the WalMart Everstart Marine Group 29 battery which has a rated capacity of 122Ah, not bad for $90. It's rumored that Johnson used more recycled lead than East Penn, which makes their flooded batteries self-discharge faster in storage. Have you seen that?
12V 100Ah Lithiums have fallen to and below $400, even $229 on Alibaba, and I'm watching for reviews. I know from being a battery tech that the lifespan of Lithium can be under 1 year or over 10.
Although I can't reveal specifics the 1 year battery was used outdoors in Arizona.