I've read that lithium-ion cells are best preserved by charging them to be less than 80% charge and discharging them no lower than 20% charge.
I'm wondering which has the most impact on cell life (performance degradation vs cycle count) / which is most sensitive between the two?
e.g. does a lithium-ion cell degrade slower by being charged to 95% and discharged to 20% or by being charged to 80% and discharged to 5%?
More specifically, I am wondering:
- When should I ideally daily start and stop charging my phone and laptops using Li-Ion batteries, when using 60%, 80% and 90% of the capacity within the day.
- How should I set up my PV system to stop charging / stop using power from my LFP battery bank, for the same respective scenarios (planning to use 60%, 80% or 90% of the battery capacity each day before charging).
Recharging would occur daily over the course of maybe 2 hours for the phone/laptop and 6 hours for the LFP battery, discharge would depend on usage but the planned discharge capacity would occur within the 24h cycle for both (minus respective charging durations).