I think EastPenn/Deka make very good batteries, I would always choose them over johnson controls.
The Deka intimidator is a very good 'budget' AGM, but it does not share the attributes of Non budget AGMS.
The Deka intimidator says to limit amperage to 30% of capacity( 30 amps per 100Ah capacity)
Its CCA figures are no better than a flooded starting battery of same size group, in many cases worse, as is th total capacity.
Its self discharge is not much better either.
As a starting battery never deeply cycled these detractions will never be noticed in most usages.
Still the Deka intimidator will benefit from an occassional top charge from a grid powered charger, as AGMS become more petulant and will lose capacity faster when they have to reside in the 90 to 95% charged range, compared to their much cheaper flooded brethern.
Odyssey and Northstar AGM$ are not budget AGMS, and they do have super low self discharge, very high CCA figures and can be deeply cycled and have a remarkable ability to still start an engine when very depleted and at cold temperatures
However when deeply cycled it is very important to high amp recharge them, and then to recharge them to a true 100% full to retain their full performance / attributes. The alternator/vehicle voltage regulator combo cannot be trusted to do this properly, and very few plug charging sources can meet a 40% charge rate, and fewer will also hold an absorption voltage of 14.4 to 14.7v for the 4 hours required after it is first attained at this 40% rate, or hold it until amps required to maintain absorption voltage decline to 0.5% of capacity.
That is how an AGM battery is determined to be full, NOT by a green light on a plug in charging source, but when the amps required to hold absorption voltage decrease to 0.5% of the standard 20 hour capacity figure.
Meaning a voltmeter and an ammeter and ideally a charging source which can maintain absorption voltage for the required duration are all present and in use, are required to prperly and fully charge these high$ agms when they are deeply cycled, inadvertently or not.
Sure these high$$ AGMS will last an OK lifespan if these rather stringent recharge requirements are not met, but one might not be getting their moneys worth from them, and they are a lot of money.
So when treated right they are an awesome battery, when treated marginally they are not all that great and perhaps not worth the expenditure over the les$er AGMS or a regular flooded starting battery.
Too often the rather ridiculous price of AGMS has the purchaser imbue their battery with super battery status, but no battery is immune to incomplete or chronic undercharging, and as always the worst battery kept fully charged will outlast the best battery chronically undercharged.
So without knowing how any given battery was treated during its lifespan, internet longevity reports, good or bad, are meaningless.
And one cannot simply look at voltage to determine how a battery is being treated. Voltage and amperage when charging is much much better. On a flooded battery the hydrometer is the battery polygraph. But voltage alone, reveals little unless it is watched like a hawk during all charging and discharging and the hawk develops a sense of where teh battery is, state of charge wise throughout its lifespan.
The following is some lawyer approved material mostly written by emotional overexcited marketers, but I think a few engineers got some input in there as well:
http://www.eastpenn-deka.com/assets/base/0139.pdf
The Deka intimidator is a very good 'budget' AGM, but it does not share the attributes of Non budget AGMS.
The Deka intimidator says to limit amperage to 30% of capacity( 30 amps per 100Ah capacity)
Its CCA figures are no better than a flooded starting battery of same size group, in many cases worse, as is th total capacity.
Its self discharge is not much better either.
As a starting battery never deeply cycled these detractions will never be noticed in most usages.
Still the Deka intimidator will benefit from an occassional top charge from a grid powered charger, as AGMS become more petulant and will lose capacity faster when they have to reside in the 90 to 95% charged range, compared to their much cheaper flooded brethern.
Odyssey and Northstar AGM$ are not budget AGMS, and they do have super low self discharge, very high CCA figures and can be deeply cycled and have a remarkable ability to still start an engine when very depleted and at cold temperatures
However when deeply cycled it is very important to high amp recharge them, and then to recharge them to a true 100% full to retain their full performance / attributes. The alternator/vehicle voltage regulator combo cannot be trusted to do this properly, and very few plug charging sources can meet a 40% charge rate, and fewer will also hold an absorption voltage of 14.4 to 14.7v for the 4 hours required after it is first attained at this 40% rate, or hold it until amps required to maintain absorption voltage decline to 0.5% of capacity.
That is how an AGM battery is determined to be full, NOT by a green light on a plug in charging source, but when the amps required to hold absorption voltage decrease to 0.5% of the standard 20 hour capacity figure.
Meaning a voltmeter and an ammeter and ideally a charging source which can maintain absorption voltage for the required duration are all present and in use, are required to prperly and fully charge these high$ agms when they are deeply cycled, inadvertently or not.
Sure these high$$ AGMS will last an OK lifespan if these rather stringent recharge requirements are not met, but one might not be getting their moneys worth from them, and they are a lot of money.
So when treated right they are an awesome battery, when treated marginally they are not all that great and perhaps not worth the expenditure over the les$er AGMS or a regular flooded starting battery.
Too often the rather ridiculous price of AGMS has the purchaser imbue their battery with super battery status, but no battery is immune to incomplete or chronic undercharging, and as always the worst battery kept fully charged will outlast the best battery chronically undercharged.
So without knowing how any given battery was treated during its lifespan, internet longevity reports, good or bad, are meaningless.
And one cannot simply look at voltage to determine how a battery is being treated. Voltage and amperage when charging is much much better. On a flooded battery the hydrometer is the battery polygraph. But voltage alone, reveals little unless it is watched like a hawk during all charging and discharging and the hawk develops a sense of where teh battery is, state of charge wise throughout its lifespan.
The following is some lawyer approved material mostly written by emotional overexcited marketers, but I think a few engineers got some input in there as well:
http://www.eastpenn-deka.com/assets/base/0139.pdf
