Just so you don't think I am only picking on West Marine or Deka/East Penn here is Trojan's line up suitable for boats.. I have installed nearly all the batteries pictured here on boats.



Top Row:

The top row are the most popular deep cycle Trojan's I see installed on cruising vessels. They are the venerable Trojan T105 6V GC2 at 225 Ah's, and Trojan's 12V golf cart battery called the J150 or T 1275 at 150Ah's. If you don't want to deal with 6V batteries the J150 / T 1275 12V GC-12 case size offers identical cycling performance to their 6V T-105 only in a 150Ah 12V GC-12 case size.


Middle Row


These are Trojan's light-cycling "deep cycle" stickered 12V marine batteries. They are lab rated at just half the cycle life of the top row and bottom row. Unfortunately all three rows are marketed as "Deep Cycle". Is this fair or honest marketing???? You be the judge.


Bottom Row


On the left we have the 12V J185 sweeper/scrubber battery. This is 225 Ah 12V battery at 1200 lab rated cycles. It is double the lab rated cycle life of the 12V marine batteries in the middle row. On the right we have the L16 6V sweeper/scrubber battery. This model is 435 Ah and 1200 lab rated cycles to 50% DOD..


If you have the height any of the batteries on the top or bottom row are great choices. Also please remember not to compare brand to brand cycle life data it is guidance only within a brand or manufacturer.