It might be helpful to refer to a trusted depth-of-discharge-versus-cycle-life-chart.
For an off-grid situation cycle life is crucial. But take a number like "500" cycles then see how great a DOD that would allow. Five hundred cycles is nothing to sneeze at. How about 700 cycles?
How many vacations equal 500 cycles? Weekends. Boondocking...?
Take care of an AGM and it will last an eyebrow raising number of cycles even at 80% depth of discharge.
But abuse will kill these numbers. These batteries must be recharged correctly.
What a lot of folks misunderstand is that battery plates get eaten whether they use the battery or not. Telecomm battery float life is something like 12-15 years. But thin plate AGMs like Full River and Odyssey only float well for 6-8 years.
During that period of time Go For It. If I hauled batteries to the wilderness every weekend they'd better be prepared for an 80% depth of discharge (20% remaining). But right after they got near a power line they would be meticulously recharged. There is NOTHING wrong with impressing 14.4 volts regulated charge across the battery, then have a timer shut the charger off. A 105 amp hour battery and a 20 amp charger can be timed for say eight hours. The extra hour or two spent at 14.4 WILL NOT HURT THE BATTERY. The voltage of course must be changed in cold weather.
Would lithium make sense for a weekend warrior or even for a 2-week camping spell, in comparison to AGM? I would like to have some numbers ran past me if you think lithium is justified under these conditions. The entire and I mean TOTAL factor of justifying lithium is TIME. Many weeks spent partially recharging the battery. Repetitive cycles.
Too often, customers read of a battery "trait" then extrapolate it to the boundaries of sanity. Chemistry does not work that way. An AGM battery will not be killed by occasional periods of 80% recharged. It's when the batteries see weeks and months of partial recharging that will occlude negative plate material.
So sifted down, flooded batteries "have their place". So do AGM batteries. And lithium construction has their optimum setting. Pluses and minuses. Strong points and weak. Compromises. Everything has it's compromising nature.
