I'm not saying the T-105's are the only way to go, but that one should not expect most group 24/27 batteries that are sold as 'deep cycle' to be 'true deep cycle'.kadet wrote:Here is why I wouldn't use Trojan T105s over proper deep cycle AGMs.
The true measure of the worth of a Lead Acid Battery is its weight as the lead plates are what determine its robustness and true cost/worth the rest is just cheap acid and plastic, lead is what costs the $$$ and gives the deep cycle perfromane.
A T105 weighs 28kg for 6V 225AH at 20hrs so you need 2 in series for 12v so 225AH for 56KG
The AGMs I use are rated at 12V 125AH at 20hrs for 36.5kg so 2 in parallel gives 250AH for 73KG here they also cost about $40 less per battery compared to T105s - I would love to get a T105 for just over $100AUD
T105s are still wet cell so they can spill when heeled, they are slow to fully charge and if one dies you only have a 6v system. They also should not be discharged below 50%.
AGMs are true SLA can be mounted at any angle, they can be discharged to 80% they can be high amp charged and if one dies you still have a 12v system.
Here, I'm not aware of any of the AGM's that have the capacity you quoted being anywhere near the cost of T-105's or comparable 6 volt batteries.
I've run for hours with the boat heeled at 20 deg or so with no spillage problems and ....
... I have both an amp meter and volt meter that I keep an eye on so have never come close to running a battery down. One does need to go down the road they are most comfortable with
,Sumner
============================
1300 miles to the Bahamas and back -- 2015
The MacGregor 26-S
The Endeavour 37
Trips to Utah, Wyoming, Idaho, Canada, Florida
Mac-Venture Links
as I said if I could get T105s here for any where near $100AUD they would be at the top of my list but I can't they are $290AUD each 
