True to a point but.....
All batteries used to cost a whole lot less, and now cost more. I don't think that T105's cost more than they sued to compared to similar batteries. They all went up with the price of lead.
I did a very carefull and detailed analysis recently of battery types for my situation and still consider the T105s' to be the BEST, when you consider price to amp hour rating. They will last around 5-6 years if taken care of properly. They will not like being discharged to 80% more than occasionaly and it WILL decrease the overall life expectancy.
I really don't get the idea that AGM's are a better battery. EVERYTHING I have read about them to me points to problems in a deep cycle useage. If maintaince free and no off gassing is what you want, then Gell cells are better for that. AGMS are good for the occasional sailor, but not a cruiser who cycles his/her batteries often.
And price to amp hour wise, they are 2-3 times more expensive and from what I have read from people that used them, will not give you the cycles a wet cell or gell cell will.
For my money
, even with the extra cabling, the hydrocaps or water
misers, the Trojan T105 is the best battery for the money
If money was not a issue for me, then a ROLLS Surrett battery, wet cell, would be my choice, but I would Pay some one to install them. Cause my back is not worth the possibility of injury.
And if designing a boat from the ground up, then I would go, like the dashews, with large traction batteries built for locomotives, or forklifts, and put them low in the bilge
, and they would be considered part of the ballest, and at over 1000 lbs, last for thousands of cycles, as deep as you would want to take them. But like anything else, you have to take care of them.
Oh and remember, using the 50% rule
, a 220AH battery will only give you ~90-100 AH of usable power. Cause you will most likely cycle them between 50-85%. That last 15 % will be hard to justify, unless you have a lot of wind
, and your needs are few. But as you go up in power useage, it will be harder to fully charge them. So a bank of 6 T105's will give a cruising boat that uses 150ah/day about 2 days before needing to recharge, unless you have solar and/or wind. Then you can go longer.
I guess it just depends on what your focus is. A boat that stays marina bound a lot and powers a lot, go with agm's or gell cells.
A cruiser, go with deep cycle heavy lead acid batteries, installed properly with good venting and with good access so they can be properly cared for.
There will always be many opinions about this. It just depends what your focus is.