So I need to replace my 12 volt trolling motor battery.  What I have in the boat is an Interstate SRM-27.  Looking at Sam's Club has the Duracell Marine Deep Cycle Battery, Group size 27 for $99.32 and the Duracell AGM Marine Battery, Group Size 27M for $199.28.  What is the difference in these 2 batteries and how will they compare to the Interstate Battery I am running now?  My Interstate was put in the boat October of 2020.  Time to replace.  I will also replace the starting battery at the same time.  I have about $500 in club points so the batteries won't cost me anything.  

The one that's $99.32 is a standard lead acid version and the one listed for double that is an AGM version.  Its maintenance free meaning there's no checking fluid levels like the lead acid one requires.

 

AGM should last you longer too.

 

I just bought 2 of these exact batteries last November (the AGM ones in size 27).  I have not encountered an issue yet.  Mine came with a 30 month replacement warranty.  200 bucks for each one is a good deal.  I think I got mine for about $215 each.

 

 

Another advantage of AGMs is that you can mount them on their sides, front or back....just not upside-down. Makes squeezing them into tight spaces easier.