By Wh of capacity may be but certainly not by Wh cycled out of the battery, LFP has many thousands of cycle life.
"LFP 12v 100AH batteries for $290": let's say 5000 thousand full cycles, 121005000 = 6000 kWh out of the battery (with still 80% capacity left), that's $290/6000 = $0.048/kWh.
> It's entirely plausible for remote autonomous systems to be discharged deeply during a rainy period of several days.
And how often is that going to be, pray tell?
Lead-Acid has hundreds of deep-discharges available. And these deep-discharges in the use case suggested (ie: 12V 20Ah Lead-Acid backing up a 3W Rasp. Pi) take 80-hours to happen with zero-sunlight at all.
So... how many multi-day periods per year do you expect to happen where you deeply-discharge such a battery over 80-hours? Even at 100-times per year (aka: every 3 days you have a full deep-discharge), with a 500-deep discharge lifespan battery, we're looking at 5+ years of durability. Worst-case scenario.
By Wh of capacity may be but certainly not by Wh cycled out of the battery, LFP has many thousands of cycle life.
"LFP 12v 100AH batteries for $290": let's say 5000 thousand full cycles, 121005000 = 6000 kWh out of the battery (with still 80% capacity left), that's $290/6000 = $0.048/kWh.