Odyssey and Northstar AGM batteries are absolute top of the Line AGM's with huge CCA and Pulse cranking amp figures which will spin your starter motor incredibly fast.
Their huge prices make their purchaseers believe they are a super battery that are immune to issues that affect other batteries, but they are NOT. In fact they could be even more susceptible to being chronically undercharged than their cheaper flooded brethern.
Do Note that if they are deeply cycled, whether intentionally or unintentionally, they need to be charged with no less than 40 amps per 100AH of capacity, and charged until 14.7v is reqached at the battery terminals, and then after 14.7v is reached at the battery terminals, it is to be held at 14.7, for 4 more hours.
Achieving this Ideal recharge regimen via alternator is pretty much impossible, and most plug in charging sources are also incapable of achieving this.
Northstar and Odyssey are not bulilt by the same company, though their internal structures are quite similar, and their CCA specs and capacity specs are exactly the same or very similar.
I own a group 27 Northstar AGM, and I do intentionally deeply cycle it. It is Now over 5 years Old, with 1000+ deep cycles on it, and many thousnads of engine starts. It is Obviously degraded in CCA, but it had absolutely no issues starting my engine depleted 12 of its 90AH in 18F weather recently. It is easily the most impressive battery I have ever owned, buut it also receives the best charging regimen.
I can feed it 40+ amps from my plug in charging source, and I can control the voltage throughout the entire tine it is plugged in. i can also control the voltage my 120 amp alternator seeks to hold the system at. The Voltage control is the Key to keeping any battery happy, and with these Thin plate pure lead AGMS, feeding them high amperage when well depleted, at least every few deep cycles is the recipe to keeping them happy.
All AGMS can be ticked to death with too low of charging currents, especially when well depleted. Ignore the 'trickle charge it overnight' recommendations you will hear when you know you have depleted it to the 50% range.
Also do not exxpect youor vehicles voltage regulation to be ideal for the battery, when deeply cycled.
When my Northstar was new, I could not get its full charge resting voltage to rest above 13v, as Northstar indicatres. I could nto achieve this until I discharged it fairly deeply and applied 25+ amps until amperage to maintain 14.4v tapered to less than 0.4 amps. Forever after that initial discharge it would rest at settle at 13.06v when rested fully charged. it also did not have that rather incredible scary fast engine cranking ability until after I cycled it once and recharged it at a higher rate.
So the Odyssey battery is Very similar in its requirements. you might not even come close too needing its abilities, but you also might not be able to achieve them unless you have the ability to recharge it according to their recommended algorithm, and that is a 40% charge rate to 14.7v.
If you never discharge it much at all then the recharge regimen is much less important, but y opinion is to get full potential from teh battery it needs one deeper discharge to teh 50% raneg then a 40% charge rate until 14.7v is reached at the battery terminals, then 14.7v held until amps taper close to zero.
http://www.odysseybattery.com/documents/US-ODY-TM-002_1214.pdf
Do not just assume its huge price tag makes it a super battery immune to sulfation from chronic undercharging. They are a bit of a princess battery in their charge requirements to reach their awesome potential, and those who cant or dont or wont understand their requirements will not get great service from them and not even come close to getting their money's worth from them.
I've no personal experinece with the ACdelco AGM's. I Put my charging source on the one in my Dads 8 month old cadilliac with start stop recently, and it was very far from being fully charged, and full charge on AGMS can ONLY be determined by how many amps it accepts when held at absorption voltage(14.4 to 14.7v)
