My parent's have a 25 foot pontoon boat and I am trying to get a new battery for him. I really do not know much about this stuff and was hoping to get a specific recommendation from someone on a battery that will do the job but stay at or under $100. I have attached a photo of the current one we are replacing. In the past he has bought what he called just a normal "starting battery" and that he saw no need for a deep cell or something. Any advice or current sale someone could point me towards would be great. Thanks!

Is there anything else that is going to be run off the battery?  What size/brand motor are you trying to start?  How are you planning on charging the battery?  

If it's for starting the motor, you want a marine starting battery.  If you're running a trolling motor, you want a deep cycle battery.

No trolling motor. Besides start up there is a radio that is installed in it, running lights at night and POSSIBLY and rare plug in of an item into the cigarette lighter.

If the one that was there was doing a good job, just get one like it or maybe more MCA.

17 minutes ago, Jig Man said:

If the one that was there was doing a good job, just get one like it or maybe more MCA. 

MCA?

Marine Cranking Amps.  The one in the pic is 625 which is not a great amount.

The MCA is going to be dependent on the size of the outboard. Match up the MCA with what the motor needs and find the highest RC (reserve capacity) that you can get for your budget.

3 hours ago, slonezp said:

The MCA is going to be dependent on the size of the outboard. Match up the MCA with what the motor needs and find the highest RC (reserve capacity) that you can get for your budget.

It is a 90 HP Mercury

7 hours ago, pauldconyers said:

It is a 90 HP Mercury

This document recommends a minimum of 525MCA http://www.dekabatteries.com/assets/base/0406MarineApplicationslayout.pdf

 

The Everstart you have is plenty big enough to get it started. Do some research on group 24 and group 27 batteries. Those will fit into your current battery box. A group 27 will have more RC than a 24

Went to Bass Pro today to talk to the guy. He agreed that I probably should stay with a group 27 battery if possible. He was also explaining to me about these AGM batteries. I told him these I have been buying seem to last about 2 years. He says a similar AGM battery should last about 10 years. Is this true? If so I would up the budget. Looking at Bass Pro it looks like any battery I buy will be on the more expensive side. Should I consider Walmart or somewhere else for this purchase?

You never answered how you were charging the battery.  AGM's require a different charging profile than wet cells.  Your original battery was from walmart.  If you were happy with it, take the core in and get another.  

Unless the charging system on the motor is made for AGM I would just stick with a flooded battery like you have.

Didn't realize there was a difference with the hook up. Yes, I probably should just do this. Thanks!

AGM batteries need a charger rated for AGM. That being said, any battery should last more than 2 years. The battery MUST be charged immediately after discharge. You need to connect it to a charger after every trip. Your motors alternator will not keep the battery charged unless you're running balls out for long distances.

Ran by Walmart today to look at their batteries. They had two different models and at the end of the spec one said DC and the other MS. What's the difference between the two and which should I go with?

DC = deep cycle, MS = marine start.  I'd get the MS