I'm using Everstart batteries, and pretty much always have. I think I had one Interstate, a long time ago, and it didn't last but a year or so, while my Everstart's have always lasted well past their warranty period. And that was back when I only had one battery to run everything in the boat, including starting the big motor (which was a 70hp Yammy).

I'm currently using a Group 24 for the big motor and console switches (including a small HB 2d depthfinder) ... and a Group 29 for the trolling motor and bow mounted Lowrance DI depthfinder. The batteries are kept charged by a Minn-Kota MK220 onboard charger. It's a 2 bank charger @ 10a per bank. The Group 24 will be 6yrs old next month, and my Group 29 is just a little over a year old. The Group 29 replaced a Group 27 that came with the boat (and lasted nearly 5yrs).

One thing I would advise to do ... is look for the mfg date sticker and get the one with the latest date. Pick them out, yourself ... don't let the floor staff do it for you (they'll grab the first one they see, or is the easiest to get to). IF the store doesn't have any less than 6mo old (on the shelf), ask if they have any newer ones in their storage room. I also check the label to make sure the battery was made by Johnson Controls.