I also thought the discussion had something to do with RV.
SMK, here is
Care of LiFePO4.
This is the manufacturer, they suggest maximum 70-80% DOD. Cyclists community has come to optimal pattern - charge it fully when it drops to 30% DOD and top-up if stored for more than 3 months.
In a nutshell - treat it like a puppy, don't let it get too hot and too cold, and feed it frequently :)... Nah, I'll better stick to my AGM...
Edit - PS: you are probably right about charging it to 80%. More than you think. When users or OEM charger manual says "fully", it really means around 90%, because the (built-in) battery management system won't let it go any higher. So you not only "don't have" to charge it to 100%, - you "shouldn't".
30% empirical DOD in e-bikes makes sense too, after some thinking. Bike has no means of recharging, except for some motors with re-generation feature. When it's down by 30% after one trip, it could be down to 60% after 2nd trip, and this is getting too close to over-discharging.
Between upper 90% and lower 30% you are left with 60% of usable charge, for all those big $$.
