I agree with you if the indicators are constantly showing lower pressure but if they pop up once per 2 week because the temperature has suddenly dropped by 10 degrees that I wouldn't start worrying about it (thats just my personal opinion). For example, my tire pressure is at 45 psi and last month (once) the sensors showed lower pressure. My car does not indicate which tires need more air (2014 model), it was -27 celcius outside. Did I go to the gas station to put more air in and to manually verify all 4 tires)? I think not (freezing as hell out there! =/)! If it would show constantly lower psi then yes you should put more air in (like you explained).
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I agree with you if the indicators are constantly showing lower pressure but if they pop up once per 2 week because the temperature has suddenly dropped by 10 degrees that I wouldn't start worrying about it (thats just my personal opinion). For example, my tire pressure is at 45 psi and last month (once) the sensors showed lower pressure. My car does not indicate which tires need more air (2014 model), it was -27 celcius outside. Did I go to the gas station to put more air in and to manually verify all 4 tires)? I think not (freezing as hell out there! =/)! If it would show constantly lower psi then yes you should put more air in (like you explained).
Unless you have a definitive source for this... I'm 99.87% sure this is incorrect.
While the (newer) car(s) do use Bosch iBoost braking systems to allow electric brake assist (as opposed to vacuum) as well as electronic control (for autopilot and emergency braking), all indications are that the car is NOT configured to trigger any regen via brake pedal.
I'm no Tesla parts expert like @lunitiks but I did read this:
Intelligent control boosts braking power « Press Info « Bosch in Japan
"The Bosch iBooster recovers almost all the energy lost in typical braking operations by ensuring deceleration rates of up to 0.3 g are achieved using the electric motor alone. It thus covers all common braking maneuvers in everyday traffic. If the brakes [sic] to be applied harder, the iBooster generates the additional braking pressure needed in the traditional way, using the brake master cylinder. The driver does not notice this harmonious interplay of motor and brakes, as pedal feel remains absolutely normal."
Understandable for the occasional cold snap, but if a 10 degree drop is triggering TPMS, then they may be running on the low side of things.
Really because when I hit my brakes I get max Regen. But I'm not 100% on it. I'm no expert.
Yes and no. There is only so much Regen available. Braking does not inhibit that is what I'm saying.
In other words, physical brake doesn't eliminate regen, brake just adds more stopping power.
I could be incorrect, but I believe the general concept of "regen on brake pedal" (rather than on accelerator letup) is that regen is initially triggered by the brake pedal. In these "blended" braking systems, the car starts deceleration by starting regen when the brake pedal is pressed, and then adding standard friction braking as the amount of additional braking requested exceeds what the regen can accomplish. I'm not aware of the usage of the physical brakes "eliminating regen"... it simply adds additional friction braking as needed. The Bosch iBooster can do this both with physical brake pedal as well as via completely electronic control, I believe.
This is in contrast to te Tesla system. which initiates znd ramps regen entirely via accelerator letup. Pressing the brake pedal only applies the friction brakes. It has no bearing on regen whatsoever. AEB and autopilot can also initiate regen by letting up on acceleration as well as also apply additional friction braking if necessary.
Thus, as far as I know, I don't believe it's correct to describe it as "hitting the brakes also regens" on the Tesla.
This is in contrast to te Tesla system. which initiates znd ramps regen entirely via accelerator letup. Pressing the brake pedal only applies the friction brakes. It has no bearing on regen whatsoever. AEB and autopilot can also initiate regen by letting up on acceleration as well as also apply additional friction braking if necessary.
Thus, as far as I know, I don't believe it's correct to describe it as "hitting the brakes also regens" on the Tesla.
As an aside... I wish the system was able to enable regen dynamically such that, even thought he battery pack is cold enough to disable regen, it could use regen to offset the ~10KW of energy my pack + cabin heaters are drawing in the morning.
I also note that the system seems to constantly undershoot the amount of regen it generates versus the dotted-line limit on the display... the margin seems to be larger as the non-locomotion power usage is greater (i.e. the heaters)
I also note that the system seems to constantly undershoot the amount of regen it generates versus the dotted-line limit on the display... the margin seems to be larger as the non-locomotion power usage is greater (i.e. the heaters)
Dealing with user controlled loads with fixed battery current levels is an interesting problem I've dealt with.
Possibly, the two issues you note are linked. If the user turns off heat during regen, the car either needs to change regen level or keep the heater on or overcharge the battery. However, the battery heater could definitely be used as a dump load (or delay turn off of the cabin heater).
There is also the issue of driver expectation in terms of how much regen they should expect. If the available level keeps bouncing around, that could lead to dissatisfaction.
Mine (mid-2013) started giving me the TPMS needs service message when it got cold intermittently a few weeks ago, and it's latched on permanently with the 7 day below freezing streak we've had; my 12v battery seems to be unhappy with the cold too, so it's going in to get both of them fixed this later week. Unsure as to whether they're going to give me the ability to see per-tire pressures or not as part of that.
I suspect they may be related as well. I was trying to see of the margin of difference between the limit-line and what the car actually does roughly equated to the draw of the heaters... but that's hard to judge during actual driving.
Agreed... I don't think a bouncing dashed-line makes sense either... I'd just be happy with the power meter dropping to zero during deceleration. Currently you can be free-coasting with your accelerator completely let up, and yet be drawing >10KW of power....
Ya, don't get me started on that basic ask again.. having car ready to drive in 1/2 hour would be sweet.
They have a smart precondition feature you might try.
They have added a "keep car warm while parked" featured, for the HVAC after you park the car. It will maintain until battery down to 20%.
This also keeps the batteries warmed.
If you can keep the car plugged into a charger it might be worth a try of dialing in a low temperature on the HVAC, and using the car keep warm feature. And set the charge point at some number... so that the charger cycles on continuously all night.
When the batteries are too cold to regen, they obviously need warming... going into a "no regen" mode is a complete waste of energy (brakes only) that could otherwise be routed to the battery heater elements, when the battery can't take it.
To help with one pedal driveability, accelerator lift-off on cold days when regen is disabled would use motors as generators and help slow the car, and the electricity does not go to battery but directly to battery heaters up to the kilowattage they can handle... what 6kW or so?
Maybe it does this secretly anyway... 6kW is not a lot of slowing power for the tonnage of this car. But at least it would be that much less wasted heat on brake discs and put where it's needed: the battery
To help with one pedal driveability, accelerator lift-off on cold days when regen is disabled would use motors as generators and help slow the car, and the electricity does not go to battery but directly to battery heaters up to the kilowattage they can handle... what 6kW or so?
Maybe it does this secretly anyway... 6kW is not a lot of slowing power for the tonnage of this car. But at least it would be that much less wasted heat on brake discs and put where it's needed: the battery
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for me recently the tipping point has been 42psi and the numbers went away (Chicago area)
