I would not do the discharge to 8% every 20 cycles. I believe this was in the P2V+ manual but it is not in the P3 manual. Doing so will reduce the lifespan of your battery. Lipo batteries should not be discharged below 30% if you want them to last. Also they should be charged at 1C and stored at a 50% charge. They should also. Be stored in a cool place - leaving them in the trunk of a hot car - especially fully charged - can damage them as well.
It is in the manual, take a read.
Battery Use
1)
Make sure the batteries are fully charged before each flight.
2)
It is recommended that you do NOT charge the Intelligent Flight Battery and remote controller at the same time.
3)
Land the aircraft immediately when the low battery level warning activates in the DJI Pilot app.
Battery Charging
1)
Charge and discharge the battery completely once every 20 charge/discharge cycles. Discharge the
battery until there is 8% remaining power or until it can no longer be turned on, then recharge it to the
maximum capacity. This power cycling procedure will optimize battery life.
2)
The Intelligent Flight Battery is designed to stop charging when it is full. However it is a good practice to
monitor the charging progress and disconnect the batteries when fully charged.
Battery Storage
1)
Discharge the battery to 30%-50% if it will NOT be used for 7 days or more. This can greatly extend the
battery life.
2)
The battery automatically discharges to below 65% when it is idle for more than 10 days to prevent it from
swelling. It takes approximately 2 days to discharge the battery to 65%. It is normal that you may feel
moderate heat emitting from the battery during the discharge process. Set the discharging thresholds in
the DJI Pilot app.
3)
The battery will enter hibernation mode if depleted and stored for a long period. When in hibernation
mode, if you try to power on the battery, the battery power LED will show a solid red light and the battery
level LEDs will all be off. You cannot manually turn off the battery power LED in this state. Leave the
battery unattended for 5 minutes, and then the light will turn off. Recharge the battery to bring it out of
hibernation.
4)
Remove batteries from the aircraft when stored for an extended period.