Batteries: Flooded vs. Gel vs. AGM

[shrew]

I have a '97 2800 SCR

I recently replaced my battery charger with a 3-leg smart charger. The older charger couldn't float and would cook the flooded batteries. The new battery charger will support Flooded, Gel or AGM batteries and is a 300Amp Charger, while the old charger was very small looked like it was made for a bass boat with a trolling and starting battery.

Now i find myself looking for new batteries and I'm considering AGM batteries (Lifeline AGM group 31's). The new charger can handle AGM batteries. Anyone have any concerns about going with AGM batteries for both Starting and House? I know the charger can handle them, but what about a stock alternator on a brand new Mercruiser 496?

Any thoughts, caveats, etc?

Steve

[hybris1]

I am running AGM batteries on my house and engine. I bought them last year and they work great. They are West Marine Group 27s. The engine battery cranks my 5.7L over better and longer than the flooded battery I had before. I had some engine trouble a few weeks ago and I had to crank and crank to get it started (fouled plugs). My flooded would not have lasted even though it was similar capacity. The only bummer is the $500 bill for two.

Do you really have a 300 amp charger? (I trust you meant 30 amp) That would draw over 3600 watts on shore power. I am charging mine with a 10 amp (5/5 amp) Minkota with no issues. It may be a little small but works great.

[Gazjen]

I was told by the designer at sterling marine power (they make lots of marine chargers etc) He told me just to buy cheap lead acid batteries as the expensive gel etc ones don't give enough return to be worth while

[shrew]

LOL, (Typo-looks like aI double-stroked the "0" accidentally) 30 Amp Charger. AGM appear to be faster to charge, more resilient to vibration and impact. They appear to hold a charge longer, have higher Amp hours, peak higher and have more duty cycles as they can be drained and recharged far more frequently and deeper than a typical flooded battery. I'm looking at 31's to replace my flooded 27's.

[jkcoon]

I put two of the Optima blue tops in my brother's champion two years ago and frankly couldn't be happier.... they just seem to go and go. I have the system on a three bank bass pro charger which maintains them quite nicely but the best part is he optimas hold thier charge so well, even without trickle charging over the winter, she is redy to go when we pulled her out each of the last two springs. They are expensive but well worth it if you are going to be putting a continuous load on the batteries such as trolling motors or inverters or if the boat sits for prolonged periods of time.... well, that's my $.02.

Happy and safe boating everyone