There is some debate and much confusion about optimal charge voltages.
Reputedly, restricting working voltages can greatly prolong-maintain lifespan-capacity.
I have noticed excessive losses in capacity due to .... abuse?
Possible abuses are:
Excessive discharge rates
Excessive charge rates
Excessive charge voltage
Excessive DOD (Depth Of Discharge)
All are potentially damaging!
As with most everything, heat is the enemy!
Lithium is a fairly unique battery technology, at moderate rates, heat production is nearly non-existent.
Anything that produces heat creates "damage"! (Pushes cell beyond "optimal")
As for charge-discharge rates.
I try to limit charges and discharges below .5C, 15Amps from a 30Ah pack.
One thing I noticed is that this .5C should be from the actual present capacity, rather than the original. When the capacity of my 26Ah recycled Laptop Lipo build dropped below 18Ah, I noticed the pack getting warm when charging at 10A. Likewise, standard output, with the diminished capacity, began producing noticeable heat.
Once heat begins being produced during normal use, damage is progressive and accelerated.
