how to evaluate batteries

[RushFan]

I am looking for new batteries.  I will go from a 12 volt trolling motor to a 24 volt tm.  Do I compare batteries by reserve minutes?  I noticed that the Optima reserve minutes are significantly lower than a standard wet cell like Interstate. I am looking at the same size (27).  I also noticed the BPS version AGM's have higher ratings. Help.

[CatFan]

For TM use, RC or reserve capacity is the best thing to look at.  A typical Group 27 is about 180 minutes.

When it comes to batteries, there is no substitute for lead, so you'll see the BPS and Cabela's AGMs weigh a good bit more than the Optimas, and have a larger RC.  Price the Cabela's AGMs.  They are usually a good deal, especially when they are on sale.