Agm vs Normal battery

[Justin L.]

I currently have a 92ah agm battery that I use for my trolling motor on a 12ft jon.  The trolling motor is my main motor(transom), because I can only use electric motors at the lake I fish. I want to get another battery, but AGM batterys are 2-3x more expensive.  Can someone explain to me all the nuances and how/what maintenance i will have to do after every trip if I get a normal/flooded battery? 

[slonezp]

2 hours ago, Justin L. said:

what maintenance i will have to do after every trip if I get a normal/flooded battery? 

Charge it

[fishnkamp]

slonezp is right use it all day and recharge it right away for maximum life. I have run the same 3 Cabelas group 30 AGM batteries for over 7 years and they are fantastic. I also plug in my on board charger when I return.

 Make sure to purchase a charger designed for charging AGM batteries. They are not expensive but you need one. They charge differently and the charger knows how to do it correctly.

[jbh3]

Water level must be maintained in a flooded cell battery. Distilled water is recommended. AGM's are sealed and require little to no maintenance. Keep terminals clean and tight whichever way you go.

[Justin L.]

11 minutes ago, jbh3 said:

Water level must be maintained in a flooded cell battery. Distilled water is recommended. AGM's are sealed and require little to no maintenance. Keep terminals clean and tight whichever way you go.

So when water levels go down just refill?  And also can you explain to me why AGM's are so much more expensive if they perform the same?  thanks so much

[slonezp]

1 hour ago, Justin L. said:

So when water levels go down just refill?  And also can you explain to me why AGM's are so much more expensive if they perform the same?  thanks so much

They dont perform the same. Wet cell deep cycle batteries are better performers, require maintenance, and must be mounted top up bottom down. agm's require no maintenance and can be mounted in any configuration 

[jbh3]

4 hours ago, Justin L. said:

So when water levels go down just refill?  And also can you explain to me why AGM's are so much more expensive if they perform the same?  thanks so much

Yes, add distilled water to a level so that the plates are immersed. In a lot of cases, AGM batteries will be heavier and have better ratings for CCA/MCA and Reserve Capacity compared to a wet cell of the same group size. More lead = more capacity and more $$$. I believe one reason that wet cell batteries fail prematurely is that folks don't maintain the water level. Both battery styles need to be charged ASAP when discharged. Personally, I get better service and a LOT fewer headaches with AGM's. Good luck what ever you choose.

[BrianinMD]

3 hours ago, slonezp said:

They dont perform the same. Wet cell deep cycle batteries are better performers, require maintenance, and must be mounted top up bottom down. agm's require no maintenance and can be mounted in any configuration 

 

Can you explain the "Wet cell deep cycle batteries are better performers" portion?

[slonezp]

1 hour ago, BrianinMD said:

 

Can you explain the "Wet cell deep cycle batteries are better performers" portion?

Apples to apples the reserve capacity on wet cells is greater than the same group agm

[Way2slow]

AGM, can be used in any orientation, even upside down but has 10% less capacity when used on it's side or upside down.  Flooded cell batteries, even the ones with sealed caps must be used in the right side up position.

 

AGM is safer for salt water use.

 

AGM can cause problems with charging systems of outboard motors not designed to use them, so if the motor is more than a few years old, it's probably not designed to run AGM's.  Also, any charging system, car, boat, or battery charger not designed to charge AGM batteries will shorten the life of the battery.

 

For similar physical size batteries, (same or similar group number) the AGM will typically have 25% less run reserve minutes than a high end flooded cell battery.

 

A quality AGM that's properly charged and maintained has a higher cycle count than a flooded battery.

 

AGM does require less maintenance than flooded cell batteries but you should make it a habit to clean/maintain all battery terminal connections at least annually.

[IndianaOutdoors]

I have two walmart $120 deep cycles that are going on 5 yrs now.  I use a Schumaker auto charger after every trip.  I have only needed to add water once so far and have not noticed any diminished charge capacity.   I don't use agm batts in the boat but we have a bunch at work.  They are supposed be able to be discharged deeper and more discharge cycles before going bad.   The old optimas we had amazing longevity. avg life 10 yrs or so.  We started having problems with the newer ones and have been switching around ever sence.  Not sure who makes a good AGM batt these days.

[WRB]

Optimum batteries was bought by Interstate several years ago.

VMax makes excellent AGM marine batteries and Odessey is a popular AGM marine battery.

My AGM batteries are 2005 vintage and still going strong, they were 1 year old UPS back up commercial batteries, 2 size 31's and a size 27 for cranking/electronics etc., about $50 each. I thought if I got a few years out of them it would be a good deal. 

Tom

[Further North]

     .

[S Hovanec]

My Bluetop starting battery lasted me 11 seasons.  The Bluetop trolling batteries went 12 seasons.

 

Replaced them with Duracell (Deka) AGM 31s.  On paper, they looked to be a better option.  They have been great so far and I saved a bunch of $$$ over getting Optimas.