Please show me a group 29 AGM.
Perhaps group 27.
Group 29 seems to be a wally world thing and is the same dimensions as a group 31. Wally world also likes to use a 100 hour rate for capacity instead of the standard 20 hour rate.
The Screwy31 is not dead yet, but is now only lightly cycled and not often.
The screwy31 thread shows basically how much time and rather obscene voltage is required to get the flooded dual purpose 12v marine battery truly fully charged when heavily cycled. It basically wastes much time and solar wattage each cycle,to do so, and much effort.
Without this expended effort, it falls flat sulfates badly, quickly, and whines like a petulant child, then goes to play in traffic.
I bought the screwy31 and the Northstar group27 AGm at the same time, and could cycle each battery independently. Even though the Screwy 31 is rated at 40 more AH capacity, the Northstar would hold significantly higher voltages under load upto 65AH from full.
The Northstar-27 is now approaching the number of cycles at which I removed the screwy31 from service( ~500). Its performance continues to impress me greatly, but I meet its recharging desires. No more than 7 deep cycles without a high amp bulk charge from the most depleted state, and as full as possible as often as possible. And as little partial state of charge cycling as I can achieve.
The high amp recharge is like the wake up slap across the face, and "behave you ba$tard", and it responds to it lovingly.
I am long done with any flooded marine/dual purpose jars for deep cycle duty. The Trojan T-1275 might find a way into my system if I desire more capacity, but for now the single Northstar group 27 AGM is BOTH house battery and engine starting battery. I use 35 to 55Ah nightly 4 to 6 nights a week. a 40 amp adjustable voltage power supply, a '120 amp' adjustable voltage alternator, and 200 watts of adjustable voltage solar, allow me to be able to keep this battery performing remarkably well.
And as always, I release flatulence in the direction of any automatic 'smart' charging source, and their marketers, CEO's lawyers and beancounters.
Pfffffffffffttttttttttttt.