wa8yxm wrote:
harold1946 wrote:
There are Marine deep cycle batteries and there are marine deep cycle/starting batteries. Two different applications.
Have never seen a true Deep Cycle battery with the word MARINE printed on it... Though I can see where there would be an advantage to DEEP CYCLE for many functions on the water.
I have seen true DEEP CYCLE 12 volt batteries in assorted sizes from around Group 27 up to you can't pick it up without a forklift.. But then it also POWERED said forklift.
All the Marine/Deep cycle (usually labeled exactly as I typed it with the slash) are starting batteries which can be SLIGHTLY discharged beyond what you would do with a common car battery.
The other claim I often see that I dispute is the claim of longer life for AGM's.
When I bought this MH, It came with a pair of GC-2 Flooded wet cells, I will be replacing them soon.
The following January I added a pair of AGM's. Replaced them 2 years ago.
I also slepped in some Maintenance Free Marine/Deep cycle types I had lying about, these are OLDER than the GC-2. Those I replaced over teh course of this last summer (2013) The last one last month
So the Maintenance free roughly lasted as long as the GC-2, but both of them long outlasted the far more expensive AGMs.
I agree with you about agms not being worth the extra cost. But you are dead wrong about marine deep cycles being only a starting battery. 50 years of boating and owning at least 20 boats from 12' to 43' long I have had excellent performance from marine deep cycle batteries. A day of fishing with a big trolling motor pushing a heavy center console fishing boat can virtually totally deplete a battery. I have abused the same deep cycle batteries over and over again, not to mention the very hostile salt water environment they have to survive in. They hold up extremely well in a much more demanding environment than RV usage. Yes they are often used as starting batteries too, and there are combination starting/deep cycle batteries available too (I have never bought one). But marine deep cycle batteries typically last for 5 to 7 years for me in every RV I have owned (class C, A and 5vers). You are entitled to your opinion but it just doesn't hold up compared to what I have seen in actual use. Oh, and I used to buy, sell and repair boats after I retired as an engineer. Now there are some very expensive extra heavy duty group 27 deep cycle marine batteries that commercial fishermen and guides like to use but they are way more than the average boater or rv person would need. They would be good for a serious boondocker with solar charging.
