laptop batteries charging myths - Long life OR short life
The best report on this subject

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The lowest aging rate is known to be 0'C 66% SoC which is the approx. SoC  charge level used by OEM's to ship/store LiPo batteries.

Depth of discharge %DoD, greatly affects total lifetime Ah capacity.

             NMC     LiPO4
 100% DoD   ~300    ~600
 80% DoD    ~400    ~900
 60% DoD    ~600    ~1,500
 40% DoD    ~1,000  ~3,000
 20% DoD    ~2,000  ~9,000
 10% DoD    ~6,000  ~15,000








Control depends on laptop OEM and bios + drivers.  Lenovo has the best user options for float charge level and slow charge option prior to going mobile to get max capacity.   Choose Longest life settings for 70% to 80% float SoC rather than  100%.


  "A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. To make this feature user-friendly, a device should feature a “Long Life” mode that keeps the battery at 4.05V/cell and offers a SoC of about 80 percent. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4.20V/cell"


Also FYI http://batteryuniversity.com/learn/article/why_mobile_phone_batteries_do_not_last_as_long_as_an_ev_battery

https://batteryuniversity.com/learn/article/rising_internal_resistance

https://www.researchgate.net/publication/303890624_Modeling_of_Lithium-Ion_Battery_Degradation_for_Cell_Life_Assessment

https://batteryuniversity.com/index.php/learn/article/bu_808b_what_causes_li_ion_to_die