FIMI X8 Battery management - Aug 15

With help of experts on this forum, set up following;
A) Charging
A-1) Stock charger
A-2) B6 charger (Please note I use clone charger so suggest to use SKYRC original charger)
B) Storage
B-1) Stock charger
B-2) B6 charger

Battery history
Using 3 batteries but on June 20, killed No. 2 battery (at 64 cycle) due to over-discharge during 7,264m range flight – 70m short landed.
Purchased another battery, so now operating 3 batteries.
No.1 Feb. 4, 2019 with X8 – 97 cycle
No.2 Purchased May 8, 2019 – Killed at 64 cycle
No.3 Purchased Sep 24, 2019 – 51 cycle
No.4 Purchased Jul 14, 2020 – only 4 cycle

Timeline is;
0:11 Charge with stock charger
0:36 Charge with B6 charger
0:53 Select LiHV
0:57 Select CHARGE
1:10 Select 3S
1:14 Select 4500mAh
1:20 Select 3A (same as stock charger but can be set at 4.5A=1C)
1:33 Activate battery
1:38 Start charging
1:44 3S Confirmed
2:47 Storage with stock charger (when battery is used and LED 2 or less)
2:51 Normal charging but stop when LED 2 or 3 flashing (50 – 60% remaining)
3:21 Storage with B6 charger (Fully charged battery or empty battery can be stored condition with this setting
4:04 Select LiHV STORAGE
4:14 Select 3S
4:20 Select 4500mAh
4:24 2.0A (Max.)
4:27 Low Voltage as battery is not activated
4:36 Activate battery
4:44 Start
4:51 Start charging as battery is less than normal storage level
5:7 Check battery condition
5:50 No. 4 battery – 4 cycle
6:08 FPV Screen Record (AZ Screen Recorder)
6:11 3.84/3.85/3.85v 0.01v difference 4 cycle
6:23 No over-discharged
6:34 Changing battery
7:24 No. 3 battery , 51 cycle
7:41 3.87/3.87/3.86v 0.01v difference 51 cycle
7:52 No over-discharged
7:59 Changing battery
8:45 Using cooling fan
8:51 No. 1 battery 97 cycle
9:33 3.91/3.92/3.93v0.02v difference (bigger than above 2 batteries)
9:49 No over-discharged