Gotta watch shedding of 4% off the life of that $150 telecom battery!

With shore power, who cares? Charge a Lifeline at 20%. 20 amps per 100 amp hours rating?
I'd bet less than one percent of ALL shortened lifespans of AGM batteries is caused by saturated voltage recharging and 99+% is due to incomplete wishy-washy fumbling. I moan when I spend a hundred dollars for fuel. But some say those dollars are not as important as dollars spent on buying batteries. Battery buying dollars are worth 10 times as much.
Tip: Don't bother attending economics class...