AGM Batteries, any thoughts, suggestions, opinion(s)?

[Lou]

I am thinking about changing over. I have a 24V motor, and am considering trying one in series with my lead acid battery just to see how it holds up. Not sure if that would be an issue. Any advice on brands, if they are that much better or anything else you think I should know before I buy?

[skiptomylu]

You should at least look at Optima Batteries and yes I know they cost more than other batteries, but they are made different too. I bought one starting battery and two TM batteries 2 years back and both winters for here were pretty cold and I checked them several times especially this year since my boat got stuck in my slings when they dropped the lake. So through all the cold weather and my boat hangs in a boat house that is much like a shed with maybe half sides and open front and back. They never needed charging and everyone I ever talked to that had them said they had theirs for 6 years or even more and still going.

Marine: Fishing: Find Your Optima


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[Lou]

I know they cost more, but all indications seem to be that you get more out of them too. I am hearing that they seem to work longer per charge as well. Thanks for the confirmation!

[skiptomylu]

Yes they do and just look into how they are made, like the post doesn't screw in it's part of the inside lead. They don't corrode, they last longer.

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[Lou]

Optima seems to be the leaders in the field. I have only found 2 other brands so far, but Optima is by far the most widly available from what I have seen so far.

[Barnacle Bill]

Not a good idea to mix batteries. Do not mix non-identical battery types, battery manufacturers or capacity in series because the battery (or cell) with the lowest capacity will overcharge or over discharge.

[Lou]

Not a good idea to mix batteries. Do not mix non-identical battery types, battery manufacturers or capacity in series because the battery (or cell) with the lowest capacity will overcharge or over discharge.

I charge them separately, but I was thinking that even though one would tend to discharge faster, it might not be that much of a problem. Perhaps I'll reconsider...

[skeetbum]

Not a good idea to mix batteries. Do not mix non-identical battery types, battery manufacturers or capacity in series because the battery (or cell) with the lowest capacity will overcharge or over discharge.

That's my understanding also. I just put in a new charger and it warned of mixing battery types. 12 volts is 12 volts, I know, but my understanding is that they don't work together like you would think and decrease the overall life of them. I'm no expert but that's what I understand from what I've read so far.

[Lou]

That's my understanding also. I just put in a new charger and it warned of mixing battery types. 12 volts is 12 volts, I know, but my understanding is that they don't work together like you would think and decrease the overall life of them. I'm no expert but that's what I understand from what I've read so far.

First of all they all have different internal resistances, so that means they are going to discharge at a different rate. Even identical ones will have a minuscule difference. Then if one is not charging as fully, and you really need to check specific gravity to know, then the more fully charged one will have to work harder to compensate as the lesser charged battery is incapable of supplying the necessary current. At least that's my understanding.

[CrappiePappy]

Lou .... you might want to look thru this : Deep Cycle Battery FAQ Yeah, OK ... it's trying to sell you THEIR battery brand --- but, the overall info is good stuff.

... cp