From the link Phil posted:
"If you’ve held onto a phone for a year or more, you’ve probably noticed the battery doesn’t seem to last as long as it did when it was brand new. Two years down the line and many phones struggle to make it through the day on a single charge. Holding onto a phone past three years can even spell trouble for system stability.
Unfortunately, battery capacity inevitably declines with age."
They made another point that people abuse there phone batteries by
not charging them correctly , majority of people charge near 0 % up to 100%.
Plus improper charging techniques like leaving the charger on over night even after the battery reached full charge.
They also made a point that said it doesn't matter with
phone batteries because you can pick a new one up cheaply.
With the Li RV batteries if you charge them correctly your supposed to get the charge cycles in your battery specs.
The thing to remember is Li is cheaper then lead acid in the long haul.
I find the interesting thing about the Li batteries is even after they get old you still are supposed to have around 90% of original capacity and they say the BMS is way more likely to fail then the battery cells , if the BMS did fail , means that you could take the battery apart and buy a aftermarket BMS with all the protections and be back in buissness.
Many videos on YouTube showing how to do it .
Cheap n easy