Battery Sealed flooded vs AGM

[Robob]

I am going to need to replace my group 24 sealed no maintenance flooded cell battery soon.

I want to stay with a sealed unit.

Any strong opinions on using AGM instead?

I have read you have to be careful charging an AGM so it doesn't overcharge.

Thanks in adance,

Bob on Tampa Bay

[Robob]

That's thanks in "Advance":-)

[fitz73222]

That's thanks in "Advance":-)

Nice save! You need a quick reaction time before the grammmer amd speeling ticks latch on!

I'm a lead acid kind of guy... Never straying far from the same I've done for the last 51 years. I guess the logical question would be whats the ROI for the added expense / life expectancy? I replace my batteries at 4-5 years; working or not. I'm really anal about not overcharging them and cleanliness and have not had problems. I really only need to add water to them about twice a year and its because I make sure I don't boil them to death on the charger.

[seabob4]

In my opinion, neither is more beneficial than the other, from a construction/chemistry standpoint.  Also, IIRC, AGMs and lead-acid batts can be charged at the same charger output levels, it's the gel cells that can't take the higher voltages.  If you go over to THT, there are a TON of threads on lead/acid VS AGM...

What I really think is important is the quality of the batt, regardless of type.  I prefer East Penn or Deka.  But even some of those fail prematurely...

[wingtime]

I bought a AGM type battery for my Cessna.  I liked the idea of it being sealed since I was having corrosion trouble in my battery box.  I also liked the idea since it was advertised as holding a charge if it sits unused for a long time.  (like boats do)  This was the first new battery technology that was approved by the FAA for small aircraft in YEARS.  Since the company has to pay massive $$$ for that FAA approval I figured it was worth a try.   And at $200 for a small battery it was not cheap.  Well it failed in a few months...  They sent me another one under warranty... it failed...  I gave up and went back to the same old flooded lead acid battery.  I talked to a airplane mechanic friend of mine the other day and he was working on a plane that had the same battery I had tired and he said it had failed as well.    So for my boat I just use a cheapy lead acid marine deep cycle and replace them every two years or so.  I just bought a group 24 marine starting battery for my jet boat project at Wally world on Saturday for $58.

[seabob4]

Wing,
I have 2 FAILED Cabelas AGMs in my shed right now, waiting to dispose of them.  Guess what?  MADE IN CHINA!!!!!!!!!!!!!

Go effin' figure... :x  :x  :x

[Bobber]

That's easy to figure, Bob. AGM batts are relatively high priced and more importantly not classified as a HazMat for ocean freight, so it's very profitable to fill up a 40' container in China or India with the cheapest battery they make and slap a 20 cent label on it for sale over here to boaters who think more $$$ makes it better. (there are several USA made AGMs that for some might actually be worth their astronomical price)  Traditional wet cells are HazMat freight, so its not profitable to bring them in by ocean. But its cheap to transport hazmat via motor freight and rail, which is why 90% of the 12v batteries sold in the US come from the Johnson Control factories in Mexico. Walmart,Interstate,Auto Zone, Die Hard,Motorcraft,Pep Boys etc etc etc all get their wet cells from the same factory in Mexico, just different labels and warranty policies set by the seller.  All the same batteries within each given size range, so buy the one that is less than 1 month old, cost less and has the best warranty.  Me, I use the Walmart Maxx 29's , best reserve capacity for the dollar (210/$80), 18 month OTC exhange at any Walmart and I get 3-4 years service out of every one running a non-digital 24v troller.

[Robob]

Thanks for all the good advice.

I think for lack of spills, since it's under the console, I'll stay with the  sealed flooded lead acid type:-)

I have a jumper that I keep up to snuff and take it with me for insurance.

Bob on Tampa Bay