I Suggest going to this Site :
https://saft.com/energizing-iot/lithium ... r-lifespan You can read :
" Contrarily to some received ideas, Li-ion batteries don’t have a memory. They don’t need regular full discharge and charge cycles to prolong life. It’s actually the contrary: the smaller the discharge (low DoD), the longer the battery will last, the more cycles it will be able to do.
Indeed, a full charging and therefore high currents boost the cell’s capacity but cause stress to the electrode which stretches, thickens, and enlarges itself to allow all the ions to penetrate. Conversely, when completely discharged (below 2.7 V), an internal chemical reaction occurs, the electrode oxidizes and retracts, the elasticity changes and the battery ages more quickly. "
A small charging Current is often better , but the provided chargers do not allow selecting this ..
Batteries are a whole " Know-How " ... not that simple ..
Mike ..