In the Dutch Renault forum, the issue came up that the maximum regenerative power allowed is higher than what CanZE reports as the Max battery charge / regen kW power. Based on a few experiments of my own only, it seems the Zoe will allow double the reported power for regeneration, capped at 40 kW DC of course. After all, it is supposed to be a short burst and the amount of energy, by definition, has already been taken from the battery.
I would appreciate your findings. Just open CanZE on the driving screen and whenever the Max battery charge / regen kW is substantially below 20 kW, try to do a serious regenerative brake (from a high speed works best, i.e. a motorway exit) and see how far the DC Power kW (or if it refreshes too slow, the blue kW in the dash) shows please. Thank you!
Edit: based on my own testing it seems there is indeed a short over-power possible. The rough formula is max_charge_power * 1.65 + 3.5. More testing by Borut suggests this seems sustainable for either roughly 40 seconds, or until the total battery voltage reaches 390 volts (4.06 volts per cell), see the comments.
It should be possible to calculate the max regen power by taking the max_regen_torque (the blue bar in the driving and consumption screen) and multiply that by the wheel speed (in rad/sec). I might implement this in a test screen.