Time after time, I learned to maximize recharge and I've come to this:
There's a noticable difference in the charging current: in this run we have a steady flow to the end of the slope.
On the previous attempt, charging was interrupted by the intervention of the braking system that was triggered by a hole on the road: whenever the system senses the wheels losing grip during regenerative braking, "classic" braking kicks in, disabling regeneration.
This is even more evident in the following graphs, where wheel cylinder pressure is sensibly lower than the previous run.
Previously, pressure ramped up and current levelled down.
The pratical effect of having a fully charged battery can be felt in the next 3 km, where the car runs in EV mode up to nearly 70 km/h.