Battery life

[el jefe]

I bought my Marlin 2005 3 years ago. I have not changed the batteries since I took ownership. I do not know but suspect the batteries may be original. Assuming the batteries are at least 3 (and probably at least 4) years old, what is the average battery life. Boat is in water 24/7, has shore power. I always show a solid 14 to 14.3 on the meter. I am thinking that maybe its time to replace the batteries more for the ounce of prevention way of looking at things. If so, what is recommended to replace the 4 batteries with.

 

[seasick]

There is no magical formula for changing batteries. Some do it routinely every few seasons. I wait until it looks like the battery is going. I have seen batteries last 10 years for some folks and only two for others. The major factor in battery aging is heat, yup not cold. So if you live in a hot climate or your batteries are mounted in a hot space, life is reduced.
The second factor is overcharging.

 

[lgusto]

I replaced the batteries on my 2005 about two years ago. They had solid readings but had increasingly short usage times. I went with AGM batteries, which were a bit more expensive than others, but have been delighted with their performance.

 

[el jefe]

Given that the boat is in the water and I am in So. Fla., I think the smart move is to replace the battery. Now the question is to go AGM or not. I have 2005 225 four strokes and a guest battery charger (also from 2005). Dekka or Optima or some else. Any feed back would be appreciated.

 

[White Horses (Mike)]

My tournament 225 is on it's fourth season with original batteries - so they are probably 5 years old. Yesterday we were tied up at the beach on one of the local islands and we used the 12v blender and the radio all afternoon. When we turned the key we did not have enough juice to turn the engine. I was pleased that my tendency to use only one battery for these beach trips paid off... The other battery started us up fine. These beach/blender afternoons are pretty regular behavior for us and this is the first sign of battery weakness I have seen. I will probably see if they can make it through this season and replace them in the fall...

Btw - what is an AGM battery and why are they more expensive or desirable!?

Thanks...

 

[Bill_N]

I have consistently gotten 4-6 years out of top quality lead acid batteries since I've been boating and see no need to spend the extra money on AGM's. In fact there were some studies done recently that indicated AGM's had a higher premature failure rate than lead acid batteries.

If you have 4 batteries you may want to replace 2 this year and 2 next year just to spread out the cost.

 

[seasick]

Given that the boat is in the water and I am in So. Fla., I think the smart move is to replace the battery. Now the question is to go AGM or not. I have 2005 225 four strokes and a guest battery charger (also from 2005). Dekka or Optima or some else. Any feed back would be appreciated.

Make sure your motors support AGM, not all do.
Also if you use a battery maintainer, check compatibility also.
All that aside, if the batteries are working, wait.
You will know when they start to die.