Volusiano wrote:Then, at a complete stop, I must assume that the mechanical brakes stay on to keep the car in place, right? Surely, you can't rely on regen to keep a car stationary in place.
This is correct. The friction brakes are needed to bring the car to a complete stop and hold it there.
Herm wrote:You could rig up an indicator if you monitor the hydraulic pressure in the brake lines.
There are two approaches that I use to determine whether the friction brakes are being applied or not:
1. Monitor the Energy Info screen. If you increase pressure on the brake pedal and the amount of regen (kW) doesn't increase (go further below zero on the circular, graphical gauge), then you know that the additional braking is being done by friction.
2. Look at the efficiency meter above the tree growing area. The indicated efficiency will drop whenever the friction brakes are applied. Of course, that's not the only thing that affects the indicated efficiency.
planet4ever wrote:Nissan seems to be concerned about doing too much QC, so the regen level might also be about as high as they feel comfortable having it. Of course most people don't regen for 30 minutes straight, but if you're dropping 5000' feet like abasile does routinely ...
For most of this descent, we are doing in the range of 10-20 kW of regen. I believe I remember reading that QC can do 0%-80% (usable) SOC in 26 minutes, and that it maxes out at 50 kW, with a taper as the SOC approaches 80%. So I don't think we are hitting the battery quite as hard as QC.
It seems to me that Nissan is more conservative with continuous regenerative braking than with quick charges, probably because the former could potentially be done with much greater frequency. Even when the car has a little under nine bars of charge, we notice that it starts to limit continuous regen to ~ 10 kW after we've descended a few thousand feet. At 10 bars after a few thousand feet of descending, we might only have ~ 3-5 KW of regen. This is why we like to start our descents with 7-8 bars of charge or less. We've been making that 5000 foot descent once or twice per week on average.