I guess I would prefer regen (or rather, the braking effect of the motor) to continue working even when the battery is full, if that is technically possible.
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I guess I would prefer regen (or rather, the braking effect of the motor) to continue working even when the battery is full, if that is technically possible...
I would think it would be entirely possible to provide some mechanism to "waste power" when regen is helpful but the battery is already full. At the most simple it could just be a big resistor+heatsink that the extra regen power is dumped into.
Hmm, perhaps turning on the cabin heater or AC either manually by driver or automatically by car when battery is "full" and regen braking is in place? On the other hand, short of very specific situations like Roadster being towed (and on) or driving downhill immediately after charging full, such confluence of conditions seems atypical.I would think it would be entirely possible to provide some mechanism to "waste power" when regen is helpful but the battery is already full. At the most simple it could just be a big resistor+heatsink that the extra regen power is dumped into.
...On the other hand, short of very specific situations like ... driving downhill immediately after charging full, such confluence of conditions seems atypical.
Yes, well, some people do live at the top of a hill and charge fully before starting their daily drive. In their case it would be a typical condition.
Hmm, perhaps turning on the cabin heater or AC either manually by driver or automatically by car when battery is "full" and regen braking is in place? On the other hand, short of very specific situations like Roadster being towed (and on) or driving downhill immediately after charging full, such confluence of conditions seems atypical.
I would think it would be entirely possible to provide some mechanism to "waste power" when regen is helpful but the battery is already full. At the most simple it could just be a big resistor+heatsink that the extra regen power is dumped into.
Is there an ability to adjust percentage of charge in performance or range modes?Our house is about 0.4 miles up a hill with a very steep 500-foot driveway. It is a momentary surprise on those rare occasions when I'm charged all the way up in range mode and start down the driveway and quickly realize I need to apply the friction brakes. It happens so fast, I don't even realize what the issue is until it's solved.
Is there an ability to adjust percentage of charge in performance or range modes?
Well, for scenario like yours instead of dumping excess regen energy I thought it would be possible to adjust standard mode to charge up to say 79.5%. This way extra .5% of battery pack would be available to absorb regen energy when starting downhill after unplugging the car.No, or 'sort of' depending on what you want to accomplish. The whole thing is pretty goofy. The charge modes set not only the portion of the battery pack to be used, but also the power limit.
Well, for scenario like yours instead of dumping excess regen energy I thought it would be possible to adjust standard mode to charge up to say 79.5%. This way extra .5% of battery pack would be available to absorb regen energy when starting downhill after unplugging the car.
From your description of different modes it seems that a similar effect will be achieved when charging up in normal mode, then switching to range or performance mode before starting to drive downhill. On the other hand, adding ability to adjust percentages via VDS and setting as preferences seems more convenient than cycling between modes.
It may be that you could max out the limit if you had an immediate decent of several thousand ft. after charging but I have no way of testing that where I live.
You'd need a pretty big descent. The extra 10% of the battery that you have to fill is about 5.3kWh. The mass of the car is a little over 1200kg, so the gravitational potential energy is about 12,000 J/m (since g is about 10 on Earth and gravitational enegry is mgh). One kWh is 3.6MJ so if you were perfectly efficient in transferring the potential energy into the battery it would take 5.3 * 3.6MJ/ 12,000 J/m = 1590m, or more than 5000 feet.
The descent from the observatories at the peak of Mauna Kea (13,803 feet) down to Saddle Road (6,600 feet) is about 14 miles, but that is a very nasty gravel road above the visitor center at 9,000 feet.
Is there a higher and steeper paved descent with electricity at the top anywhere on the planet?
Actually yes, there is. If you took your Tesla to the top of Haleakala volcano in Maui (10,023 feet) you could coast all the way back to sea level in about 30 miles. If you don't have your Tesla it is also a fun thing to do on a bike (I did it last month).