Forty Creek
Member
I have the HPWC for all of the reasons you list. One caution, I've found the "plug hook" to be rather useless. It does not hold the head unit securely and so I just leave it dangling from the coil of wire.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
I have the HPWC for all of the reasons you list. One caution, I've found the "plug hook" to be rather useless. It does not hold the head unit securely and so I just leave it dangling from the coil of wire.
110V only gives you 1.2 kW. Maximum power for the pack heater is 6 kW. Clearly it can't give you full heating power. There are reports that in extreme cold (e.g. -20C) it won't even charge the battery; it just tries in vain to warm the pack and never gets to charge.
Understandable. Back in the day I wouldn't take my Roadster out of the garage without at least one charge cable.
These days there are J1772 stations all over the place. The little adapter stays in the car at all times, so I'm pretty much covered.
Yeah if can be a bit finicky... I found that as long as I have the "flex" of the cable oriented in the right direction it will hold. Even if you don't hook the plug-head itself, it serves as a hanger to coil the cable on. Incidentally, the HPWC head itself is also designed to be a cable hanger.
I coil my cable around the top of HPWC and the bottom of the hanger. That way it gives some tension in the coiling and becomes a much tighter wind.
I didn't even think to order the HPWC so I could keep my UMC cable in the car. I paid $600 for an extra cable (which I realize now I never use). And the HPWC would have qualified for an Ontario rebate. My NEMA 14-50 did not. So maybe I would have actually saved or at least come out even if I had gotten the HPWC instead of paying for the extra cable.
mnx
2018 M3P
I think yesterday was officially my least efficient day in the Model S ever. I drove about 75km total (across 5 trips or so), but used nearly double the amount of rated range!
At the end of the day it was about 75km driven, 308Wh/km, and 32.19kWh pulled from the wall (for a wall to wheel efficiency of 429Wh/km).
At the end of the day it was about 75km driven, 308Wh/km, and 32.19kWh pulled from the wall (for a wall to wheel efficiency of 429Wh/km).
Cottonwood
Roadster#433, Model S#S37
Yes, those are the effects of winter.
ICE vehicles are also less efficient and create more emissions warming up from a cold start. In very cold climates, its typical to have block heater outlets at many parking lots. I wonder if Tesla has considered a "keep me warm" mode that draws a kW or less from a regular 5-15, 120-Volt outlet?
mknox
Well-Known Member
I also keep track of input power. I track my own use via a sub-meter and track public charging on a spreadsheet and tally it up each month. Even in the summer, there is quite a difference between the car's Watt-Hour numbers and my calculated ones.
I have a long commute (about 65 km each way) which is better for total trip consumption because the high initial numbers tend to level out over time. Today, on my trip in to work, I kept the cruise control on at 105 km/h making me the slowest guy on the 401 by a long shot. Even 18-wheelers were passing me. I pre-heated the car and had only a slight amount of re-gen as I set out. Temperatures were around -11 C and the roads were clear and dry. Upon arrival at work, I was showing 254 Wh/km which is the best I've seen over the past few cold days, but nowhere close to the 185 I'd regularly see in the summer.
- - - Updated - - -
Yes, those are the effects of winter.
True, and people constantly remind me of this, but I tracked my ICE's fuel use very closely as well, and never saw range decreases or consumption increases to this level of magnitude. Sure I used more warming up the car (I had remote start) and due to cold weather inefficiencies, but again, not nearly as much as with an EV. Not complainin'... just sayin'...
Based on the "how far can I go" on MS's website, setting speed at 65mph, turning on the heat and setting outside temp to 32F, stated range is 218 miles for the 85 KWH battery.
Your Questions Answered | Tesla Motors
Started at 70F - 255 Miles Range at 65mph
Changing only temp to 32F - 243 Miles of Range at 65mph
Turning on heat at 32F - 218 Miles of Range at 65 mph
Your Questions Answered | Tesla Motors
Started at 70F - 255 Miles Range at 65mph
Changing only temp to 32F - 243 Miles of Range at 65mph
Turning on heat at 32F - 218 Miles of Range at 65 mph
Real life Chicago weather:
20F, 70-75 mph, internal heat set at 72F, range 170 miles - made it home with 5 rated miles
Clarification:
On cruise control for most of the drive...
20F, 70-75 mph, internal heat set at 72F, range 170 miles - made it home with 5 rated miles
Clarification:
On cruise control for most of the drive...
Repeated short trips are the worst-case cold weather scenario. The pack and cabin heaters are running full blast, then you stop and the car cold soaks again. Repeat.
The worst day we ever had for consumption was Christmas shopping last year. It was below -20C, and we did a bunch of short trips with a good cold soak in between.
Even though the consumption in this scenario is very high, you don't end up depleting the pack simply because the number of trips is inherently limited. You can only do so much in one day!
Cottonwood
Roadster#433, Model S#S37
That's just a fact of life with an EV...The ICE has a lot of waste heat sent out the radiator, which can be diverted and used to warm the cabin and windshield in winter. The only time I have ever seen an ICE not have enough waste heat was sitting in a parking lot with an efficient little VW 1.5 liter diesel at idle on a cold winter day. Even though the MS attempts to capture the waste heat off of the battery/power conversion/motor setup, at cold temperatures, the car just has to put energy into resistive heating to heat the cabin. Some have wondered about using the heat pump in the winter to gain a little more efficiency, but I think at the low temps we are talking about, that is only a marginal gain for an increase in complexity. Of course, the designers making these tradeoffs do live in Palo Alto. :wink:
Actually I do believe the Model S does have a heat pump, and that once the drive train warms up it uses it as the thermal reservoir. It's the only way to explain the impressive heater efficiency once the car has warmed up.
mknox
Well-Known Member
Do we think it's a true heat pump, or are they just plumbing warm water from the motor and battery loops into the cabin heating loop? I remember talking to Hans back in the Alpha and Beta days, and he described it as not wasting any heat by throwing it overboard like you do in an ICE. This makes me thing that they're just keeping the heated coolant away from the radiators in winter and circulating the heat into the car. An actual heat pump would use a compressor and radiators or some other form of heat sink.
On a perhaps related note, I've noticed my a/c compressor running even in sub-freezing temperatures. I could hear it going on and off when I was parked and charging a few days ago. When I turned it off from the HVAC controls, I could no longer hear it go on and off. I wondered if the compressor was actually a reverse cycle a/c (aka heat pump), but have noticed no difference in energy consumption with it on or off. Most ICE cars will disable the a/c compressor below something like 40 F supposedly to prevent damage by running when it's too cold.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
My belief is that there is a heat pump which is in effect the A/C in reverse mode. Now, when you design a heat pump it can be run both ways but the overall design, choice of fluids, etc. will always make this pump either being primarily good at heating or cooling. Like my air-air heat pump at home (Mitsubishi Kirigamine 2013 model) which is a beast when it comes to heating (maintains almost 4 C heating efficiency even at -20C) but the A/C cooling effect in the summer is more of a bonus. In the Tesla I think the heat pump/exchanger/AC is designed primarily for cooling but that it also has some effiency in generating heat. I would suspect however that as you get further below freezing its heating coefficent starts getting closer to 1C which makes it behave more and more like a simple resistive heater the lower you get. Would be Nice to know the actual specs on this unit but I have never seen it published by Tesla.
On a related note, when Elon and George B held a reception two years ago at the US Ambassador's mansion in Oslo I remember one of the future S buyers there asked Elon directly about this: Will the Model S have a heat pump to give it better range in the Winter. Elon answered this With "Yes, of course we will have a heat pump" but not more detail than that.
Pretty sure it's a true heat pump. For one thing, back before they released Model S they were saying it had a heat pump, that it was based on the technology used in the Prius. You already have most of the hardware you need just having an air conditioner... an air conditioner is a type of heat pump.
I've seen the infamous service screens, and the HVAC evaporator could be selected between various loops. It could be connected to the radiators up front, and it could be connected to the drive train loop.
The Model S takes 6 kW for the cabin heater when it's at full power, yet somehow manages to maintain cabin heat with around 1 kW. That's way less than the comparatively tiny Roadster needs to maintain cabin temperature, and it only has resistive heating.
So yes, I'm pretty sure they can use the thermal mass of the battery pack and heat from the pack, inverter, and motor as a reservoir for the heat pump, and thus keep the cabin toasty with relatively little extra power.
Thanks for this!
I'm new, and pick up in 3 weeks, so please excuse any ignorance. Was your 170 miles a full 100% charge?
Your experience would get me pretty close to my round trip for work so I just want to prepare to ensure I'll make it!
I'm new, and pick up in 3 weeks, so please excuse any ignorance. Was your 170 miles a full 100% charge?
Your experience would get me pretty close to my round trip for work so I just want to prepare to ensure I'll make it!
Real life Chicago weather:
20F, 70-75 mph, internal heat set at 72F, range 170 miles - made it home with 5 rated miles
Clarification:
On cruise control for most of the drive...
mknox
Well-Known Member
Yesterday, I took a 246 mile round trip drive up to a rental property I own. I used 272 miles of Rated Range (I did charge at the destination before returning). That isn't too bad considering the temps were just below freezing and some of the roads close to my destination were a bit snowy.