Thread: Who make the best deep cycle battery?

Been employed as a EMT(electronics maintenance technician) since 1984.Have had/used a wide variety of deep cycle batteries through the years.Always compared CCA or MCA to assess battery durability.Have had /used a load tester for years to be able to gauge batteries before usage.Have charged,stored batteries during below freezing winter weather in my basement...Found out only recently there has been big changes in the "Marine Deep Cycle" batteries sold by Wally World.(Johnson Controls)Last several sets have been group 29's.(My wife works for WM and we get the Associate discount).
In the past I could pull crank baits over 8 hours and still have battery power left.The last set I bought could not begin to provide anything close to my older batteries.Maybe 4-5 hours at best.Please realize both were group 29's from WM but not an even close equivalent to each other .Different makers will manipulate their ratings to deceive the consumer .....My current set of group 29 batteries only show 845 Marine Cranking Amps,and Amp Hours @ 1A 114 (they do not display any rating for Reserve Capacity or RC)...Reserve capacity is the one and only rating you need to see and concider when buying or comparing batteries.The number of minutes a fully charged battery at 80 degrees will discharge 25 amps until the battery drops below 10.5 volts.RC is the only legitimate standardized battery rating.
You will see fellas touting how good or durable their batteries are...An example is the Trojan 1275 golf cart battery rated at 280 RC.No wonder users like that battery.That is a high RC rating.My advise is to compare your current batteries RC to gauge what you have.
My old and new group 29 WM batteries were about like comparing apples and oranges.There was no comparison.Even with a discount I will never again buy another from WM or any other battery without the RC rating available.Going to buy a set of VMAX MR137-120's rated at 230 RC from the company.They are AGM batteries and with my boat weight should perform just fine.
I am sorry this has been long-winded...Hope it helps someone so they do not get short changed(screwed) like I was.