Range Mode -- How much does it help?

[Ingineer]

I honestly thought I'd read that the heater in the S does utilize a heat pump, and has resistive heat as a supplement for when it's too cold for the pump to be effective. Is that definitely wrong?

I haven't seen it shown anywhere in the official documentation, nor have I taken a look at the plumbing (yet), but I suppose it's possible. The range hit from heat many people indicate would seem to suggest that it isn't a heat pump.

 

[Cottonwood]

I haven't seen it shown anywhere in the official documentation, nor have I taken a look at the plumbing (yet), but I suppose it's possible. The range hit from heat many people indicate would seem to suggest that it isn't a heat pump.

Here is the high level heat transfer diagram from one of the maintenance screens for an early Sig model, but this seems more focused on battery, motor, etc, than cabin temperature control.

 

[Ingineer]

Here is the high level heat transfer diagram from one of the maintenance screens for an early Sig model, but this seems more focused on battery, motor, etc, than cabin temperature control.

Well, if that diagram is correct, it does seem to show all the plumbing, including the interior evaporator, then the answer is definitely no heat pump mode. It has 2 condensers in series, and 2 refrigerant valves that can enable the chiller (heat exchanger) and/or the HVAC evaporator. There is the "Air PTC" shown which is what provides all the cabin heat, purely electric resistance, and the battery also has it's own electric resistance heater. There are also a number of coolant valves for configuring the system for heat/cool/parallel/series operation. It would need to add a reversing valve at the minimum, and would also benefit from an electrically adjustable expansion valve. In many heat pumps they also add a hot gas valve to defrost the evaporators (outside coils when in heat mode). Even so, we're talking not that much $ for a lot of extra range.

 

[djp]

Here is the series mode. It looks like the waste heat from the motor/inverter can be used to warm the battery pack. I wouldn't be surprised if it could supply cabin heat too.

View attachment 75078

 

[Khatsalano]

Range mode is about a -3% difference for me too in the current patch. It does two things as others have noted:

(1) D's torque sleep in normal mode. Range mode makes them torque sleep more, at the sacrifice of smoothness and sound quality (you'll hear more chirping). You may also find there to be a tiny bit more lag in slip conditions when torque sleep is maxed. This is not normally noticeable.

(2) Climate control's target condition tolerance is increased; maximum fan speed is limited.

- K

 

[Ingineer]

Here is the series mode. It looks like the waste heat from the motor/inverter can be used to warm the battery pack. I wouldn't be surprised if it could supply cabin heat too.

Yes, it's definitely pumping waste heat from the charger/drivetrain into the pack in that config. There is no way to heat the cabin with waste heat at all on this system.

 

[travwill]

Silly question maybe, using Range Mode for first time today and doing a full charge for a lot of driving today. Is Range Mode something that you have to turn on each time you get into or start the car or does it stay on by default until switched back off?

Also, since I drug battery to right to 100% as far as it would go, will it warn me after a period of time to switch it back to a daily level if I forget? I won't but curious...

 

[Spacela]

Silly question maybe, using Range Mode for first time today and doing a full charge for a lot of driving today. Is Range Mode something that you have to turn on each time you get into or start the car or does it stay on by default until switched back off?

Also, since I drug battery to right to 100% as far as it would go, will it warn me after a period of time to switch it back to a daily level if I forget? I won't but curious...

Range mode is persistent; it will stay on forever if you turn it on. I'm also pretty sure the car will warn you if you have the charge slider in the "trip" range after a while (IIRC 3 days).

 

[cantdecide]

Just to be clear... "Range mode" is the car setting that does the things described in this thread like less air conditioning. That setting persists and many people leave it there always.
"Range charging" is where you move the charge slider to the right to get a 100% charge. For me the range charging setting has reverted after a few days, and warns you if you frequently go into range charge.