Energy recovered while coasting vs braking

Here are 2 classic questions:

• Is there greater recovery while braking or with a gently and longer release?
• How much energy can we recover from what we used to bring the car up to speed?

Scenario:
Plain, straight, empty road with good tarmac and SOC at 60%
Test policy:
Standing start, electric traction up to 50 km/h.
Every test starts from the same location.
Electric traction is only used to estimate energy to reach 50 km/h in a way comparable to recovered energy.
Test 1:
As soon a the target speed is achieved, complete release of accelerator pedal until crawling kicks in.
Test 2:
As soon a the target speed is achieved, apply pressure on the brake pedal up to half of the CHG zone, until full stop.
Comparison criteria:
SOC gain difference, regenerated current amount, battery stress.

Test 1: coasting
Here's the chart

Speed is in blue: starts from 0, tops at 50 and then decreases until crawling speed.
SOC is in yellow: starts at 60%, decreases while accelerating and the increases again while slowing down.
HV battery current is in red: positive values while accelerating and negative while recovering.
The red positive area gives an estimate of the energy needed to bring the car up to speed, while the negative area represents recovered energy
Ratio of those two areas shows how much energy is recoverable: in this test ratio is 5.6 and recovered energy is 17.8% of the amount spent.
SOC Charge chart says that we recovered a little less than 0.8%

Battery stress is 31.03

Test 2: braking
Here's the chart

Speed is in blue: starts from 0, tops at 50 and then decreases until full stop.
SOC is in yellow: starts at 60%, decreases while accelerating and the increases again while slowing down.
HV battery current is in red: positive values while accelerating and negative while recovering.
The red positive area gives an estimate of the energy needed to bring the car up to speed, while the negative area represents recovered energy
Ratio of those two areas shows how much energy is recoverable: in this test ratio is 3.1 and recovered energy is 32.1% of the amount spent.
SOC Charge chart says that we recovered a little more than 1.5%

Battery stress is 40.43: this manouver is definitely more stressful than plain coasting.

What this could mean over the years for mileage and battery life is unknown.

Back to our initial questions:

• Is there greater recovery while braking or with a gently and longer release?

It seems that braking gains more energy.

We have to use only regenerative braking, so no hard brakes and a road with no holes that may trigger friction pads.

• How much energy can we recover from what we used to bring the car up to speed?

One third at best.

There's a thread about this on the Hybrid Synergy Forum:

http://www.hybrid-synergy.eu/showthread.php?tid=49547