AGM battery charging

[jkilday4]

I was picking up a battery from a friend's place yesterday evening and saw that this battery, a Deep Cycle style of WalMart brand, was sitting in garage on concrete; reminded me of another friend's warning to never store a battery on concrete because it would wound/kill the life of the battery.  (The battery will not take charge by the way; I'm gonna have it tested, but it's already 4.5 yrs old and not been maintained or used at all in over a year.)  That led me to research on-line; what I read says it's not the sitting directly on concrete that damages a battery but the fact that bare concrete is typically accompanied by extreme temperature swings (garage, warehouse settings, etc) which is actually the culprit.

Then I started to wonder if I have been properly charging/maintaining for my Optima Blue Top D34M battery that I use for my trolling motor.  I went to the Optima site and watched the tech tip videos and did some reading of tips on battery charging/maintenance; they said that I should not use a battery charger that has a combined AGM & Gel Cell setting - which mine does and I have been for just over two years now.  They state it will not fully charge and can damage the battery.      (I've been using a Schumacher SpeedCharge Ship'n'shore charger from WallyWorld.)

I guess I first ought to have this battery checked and see if I can tell if it has been damaged.  Do any of you all know if a auto parts store can diagnose this?  I did buy it at AutoZone; you would think they would be able to test it.

And if it's not damaged too bad, which I've not really noticed any problems - so hopefully it's still ok - then I need to get a proper charger.  Can anyone recommend a 'Smart' charger that I've been reading about? One that will desulfate & auto-maintain?  The BatteryMINDer line seems like the technology would be sufficient while the price not too bad..?  Optima's site says they are coming out with a charger of their own Jan '12 which I'm sure will be top-of-the-line and carry a big price tag too... 

I never knew charging a battery could be so complicated!

[Glenn Hawkins]

I really like, use and sell the Battery Tender products.  When BMW switched over from flooded (wet) batteries to AGM (asorbed glass mat) in our motorcycles a few years ago the charging requirements changed.  It was very suttle but the AMG batteries required a slightly higher rate of charge during the first part of the charging cycle.  Here is some tech info I found on Battery Tenders website.
   
http://batterytender.com/resources/battery-basics.htm#answer6

[Travis C.]

These are some of the best charging systems around.

http://www.dualpro.com/home/

Plus, they are located in LaVernge TN. You can purchase these at Bass Pro and other places.

[MikeA]

I second the Dual Pro. I've had them in almost every boat I've owned and never has one let me down. I don't know if they are good for AGM's but for reg batteries they are sweet.

[Steve H]

I really like, use and sell the Battery Tender products.  When BMW switched over from flooded (wet) batteries to AGM (asorbed glass mat) in our motorcycles a few years ago the charging requirements changed.  It was very suttle but the AMG batteries required a slightly higher rate of charge during the first part of the charging cycle.  Here is some tech info I found on Battery Tenders website.
   
http://batterytender.com/resources/battery-basics.htm#answer6

That is some good info Glenn.