Time to replace batteries

I have 3 batteries, 1 is for the accessories and cranking the engine, the other two are for my trolling motor.

The trolling batteries are about 6-7yrs old and don't seem to be holding a charge, so pending a test, they are most likely being replaced in the next month or so.

Is there anything special I should consider to get the best bang for my buck? Do I just get the largest deep cycle battery that will fit in the cavity or is there more to it? Most likely I'll go with Walmart batteries, because that's what these are and I've had good luck with them. These are 72mo batteries and they've lasted well over that. The ones in my vehicles are from auto stores and they are crap, but I'll gladly listen to brand recommendations.

Also, if the crank/accessory battery needs replaced, do I once again buy deep cycle or what? ....should it be the largest that will fit?

I question this, because I've seen a few diagrams that seem to spell out different batteries for trolling vs. cranking.

Motor is 150hp Evinrude, if that matters at all.

Thanks!

Re: Time to replace batteries

Batteries are like buckets, they are containers for electricity. Just because a battery is larger dimensionally, does not necessarily mean it has higher capacity so look at the labels carefully. Batteries are grouped by physical size, 22, 24, 27, 29, 31 etc. Within each group there are batteries intended for starting, deep cycle, and a combination of the two called dual purpose or marine starting/deepcyle. For your starting battery you need a marine starting or a dual purpose. For the troller you need deep cycles (not dual purpose). Now then - for the troller you are typically looking at a group 27 minimum. Those batteries are rated on the label with the numbers like this: Reserve Minutes: 150 @ 23A. What that means is that group 27 battery will deliver 23 amps for 150 minutes or 2-1/2 hours before voltage drops to a point where the battery is essentially depleated and can no longer deliver its rated capacity. So within any group size battery, the bigger this number is the better. The 23A will not change as it is simply the load used by the battery makers for testing purposes. The starting battery will be labeled with Cold Cranking amps. The bigger this number the better. You cannot go too big on a battery, just too small. There are lots of different battery types so make sure you compare apples to apples. In my view it is not necessary to spend more than $85 for a group 27 deep cycle or $55.00 for a decent starting battery.

Re: Time to replace batteries

To start your Evinrude, you can buy a deep discharge as well. Very little current is needed to start one of those and a deep discharge wil manage fine.

Re: Time to replace batteries

Called Walmart and they have a 730amp/hr with 160RC for $77. They said that was the largest they had in the Marine Battery, but looking online, it appears they have larger ones. When I say larger, I am not necessarily speaking physical size, but maybe they were!!

I want to compare what they told me with what I have currently. I have enough room to go up a size or two if available.

Bruce, you say I can go a deep discharge for my starting battery for my XP150, would that be the better way to go? I honestly don't worry as much about this battery, because I figure I always have the other two sitting right there next to it...and if all else fails I could pull out the rope....

Re: Time to replace batteries

I have two deep discharge batteries in my boat and I have a 7.4L carbed engine. Some V8s that have fuel injection are picky about voltage drop but you will not have that problem with your small motor.

Most of the marine batteries that you buy at Costco or Wallmart really aren't true deep discharge batteries anyway.

Re: Time to replace batteries

bruceb58 said:

Most of the marine batteries that you buy at Costco or Wallmart really aren't true deep discharge batteries anyway.

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Is there a certain one at Walmart that is?? One of mine is an Everstart Maxx, series 29(?) with amp hr of 205 and Reserve capacity of 875. The other just says EverStart, seems to be a series 27 with 160reserve and 115 Amp hrs(?). Don't hold me to those numbers, I'm going off what I remember seeing...

Re: Time to replace batteries

Silvertip said:

Batteries are like buckets, they are containers for electricity. Just because a battery is larger dimensionally, does not necessarily mean it has higher capacity.

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Well then it's not really like a bucket than is it?