I go the opposite way but.. Wal Mart Batteries are good but usually last about 2 years of course you can take em back next spring and trade them in for new ones. I know a couple guys that do exactly that and the first year on those batteries is very good.

I prefer optima blue tops for TM get 5-6 or more years (but more importantly can get 10 hours of trolling per charge) 2 for the 24v TM, 1 for electronics, and 1 for starting use d31m's for the TM and d27m's for starting and electronics.

Been working on getting the parts together for a friends boat and found a good deal on on d31m's on amazon for a good price.

Use a Minn Kota 460D to charge all batteries works very well unless you forget to plug it in. Idea > Docking Station for Boat!!!!!

Batteries are truly a pay me now or pay me later proposition. My Neighbor gets out almost as much as I do and is on his 4th set of wal mart batteries. My Fishing Boat was set up the first year he had his boat. I am still on my original batteries 6 years and will probably make it through the season his batteries cost about 1/2 of what mine did originally. He uses an old charger that I think overcharges the batteries but that is a different story so to date, he has spent twice as much on batteries. Could have bought an onboard charger with extra money and still be money ahead.

I come home, plug the charger to an extension cord and walk away, He charges each of his batteries individually and its now 11:30 and I just saw/heard him changing charger over again. He will be gone at 5am. I am not fishing tomorrow but at 5am my 6 year old batteries will be fully and properly charged and will stay that way until next trip.

Good luck with your choices.. BTW optima has a sepcial deal right now where you get additional warranty if you buy a battery and their charger at the same time.