After 0.1miles my trip displays 1200kw/mile.....any ideas

After 0.1miles my trip displays 1200kw/mile.....any ideas

After I charge my car either on my chargepoint high power wall connector or on a 120volt wall outlet, once my car is set to drive and even going 5 mph, my instantaneous kw/mi is really high....and only after going 2-3 miles of slow driving does my average dip into the 350-360. If I am on the freeway, it sometimes will be in the 400's with even going 60-65mph. Anyone have any ideas? Going to take it into service.

justineet | 6 agosto 2013

It sound a software glitch or the hardware which is supposed to monitor/measure energy use is defective........let us know the cause after u get it fixed......

jbunn | 6 agosto 2013

What's the outside temp? What's the temp in the car? What's your climate set at?

JoesP85plus | 6 agosto 2013

74 degrees and ac at 68 degrees....but only going 5mph....somethings wrong...seems to be using too much energy

NomoDinos | 6 agosto 2013

Definitely sounds like something that needs to be serviced. Either the sensor is wrong or it's consuming too much like you said.

justineet | 6 agosto 2013

what do u get driving 5 mph?? u say high but can u say what u actually get??

Jamon | 6 agosto 2013

@joohyunl - my car behaves in a similar way. The reading in the first update after charging is often >700 Wh/mi, then it takes several miles to get down towards 300 Wh/mi. I assumed it was because the calculation takes into account any energy consumed while the car was charging (cooling battery, etc). If you find evidence that this is abnormal, please let us know.

jbunn | 6 agosto 2013

Id have it looked at, but id say software or sensor issue. Dont think you can draw that much power without lots of heat.

negarholger | 6 agosto 2013

Mine is the same... display starts very high after charging, but then settles to expected value. Problem is your car is using energy but you do not put miles on it.
My life time total is 333 Wh / miles. At the end of my 2.5 miles comute after charging the usage is anywhere between 400 - 480 Wh / mile. Going shopping 6 miles and I am around 350. Also start stop city driving is way less efficient then constant speed driving ( regen gets you only a fraction back ).

Wayne3 | 6 agosto 2013

Likely nothing is wrong. Your trip meter shows 1200 Wh/m (watt hours per mile). You were driving 5 miles per hour (m/h). 1200 Wh/m * 5 m/h = 6000 W = 6kW.

You have a gauge on the speedometer that shows how many kW you are drawing at any given moment. The first labeled number on that gauge is 20 kW. Halfway to that is 10 kW. Halfway to that is 5kW.

It's very difficult to accelerate from zero to 5 mph without going over 5kW. (Watch the gauge and try it -- you'll see.)

So what's happening is that you're using an average of 6 kW to accelerate from zero to 5 mph, and the trip meter is correctly showing this as 1200 Wh /m. This would be a horrible efficiency if you spent all day accelerating from zero to 5 over and over again. But no one does this.

Once you get going on the freeway, it's easy to go 70 mph and consume 20 kW, for example. (Try it -- go 70 and try to keep the orange indicator averaging around 20 kW. Not too hard assuming you're not going up hill.) That's 20 kW / 70 m/h = 0.286 kWh/m = 285 Wh/m, a very respectable efficiency.

What you're seeing on the trip meter is the initial inefficiency of zero to 5 which then gets averaged out with the much better efficiency you achieve once you really get going for the bulk of your trip.

Not a problem, just a natural progression to be aware of so that it doesn't throw you off.

David Trushin | 7 agosto 2013

This is just an artifact from the trip mileage indicator being reset to 0 and the lag between measuring energy used and mileage driven. If you go to the energy page and look at the instantaneous or average numbers, you'll see you are not really running at that rate. In any case, that meter clears up after a mile or two as the measured amounts get large enough to not skew the ratio.

jai9001 | 7 agosto 2013

Agree with David. Just an artifact of how energy consumption is measured within the first mile.

nickjhowe | 7 agosto 2013

This normal. I often see the meter go over 900 wh/m if I'm in a parking garage or something.

slr_pwrd | 7 agosto 2013

@joohyunl - my car behaves same way. I reported to the Service Center Ranger who visited the car for another reason. He said it is normal behavior.

cgiGuy | 7 agosto 2013

Mine does this.. and I noticed that it's much higher if my A/C is cranked up while I'm backing out of my garage. If the A/C is off, it only jumps up to about 600kWh for the first minute or so.

brandtlings | 7 agosto 2013

Mine does that too. I've surmised that the vampire loss is being factored into the mileage. The car sits for a few hours after a full charge and looses 5 miles or so. These are all rolled into the next batch of miles til recharge. You end up with a total energy used for the miles you have travelled, including the vampire losses. Cars driven low miles between charges will have a higher wh/mile than cars driven further. | 7 agosto 2013

Mine does this too for the first mile or so--its just a math anomaly since the denominator (miles) is so small: 1200kw/mi = 120kw/0.1mi, etc If it stays pegged after a mile or so and you don't have the AC or heat blasting (or driving up a hill), then I might worry.


SCCRENDO | 7 agosto 2013

same here

Captain_Zap | 7 agosto 2013

You have to go a couple miles to get an accurate reading.

A gas car burns fuel while idling in stopped traffic. The Tesla doesn't have that problem and the energy demand is lower. The problem is in the calculations when the car sees that there has been very little forward progress in miles. It skews the data. A couple miles brings the average down to reality.

olanmills | 7 agosto 2013

Why is there so much concern over this. It's simple math. Nothing is wrong.

When you first use the car, there is more energy used than normal. Even though the battery heater and cooler does function when the car is "off" it's not as active as it is when you are driving. So when you first turn the car "on", it uses more energy to get the battery to the temperature it likes.

Also, your first tenth mile of driving is likely to be very inefficient compared to the rest of the trip. You'll be doing things like backing out of your garage, accelerating, stopping, and accelerating again until you get onto the main road, etc.

Most everyone will have a high energy usage over a low amount of distance travelled for the first minute or two of a day's driving. So of course the Wh/m rating is going to be high.

The same is true when you're leaving work and heading on your way home too, but now you already have half of your daily commute averaged in, so you won't notice it. The 0.1 mile of the start of your return trip has little effect on your total trip efficiency. However, at the very start of the day, your first 0.1 mile is your whole trip.

JoesP85plus | 7 agosto 2013

No this issue is that for the first 3-4 miles, my car is at about 400-500kw/hr and only settles down to the high 300's when I charge from a 120 volt charger. And this is with very light acceleration/braking/etc, If I use my HPWC, I don't have this issue.

Docrob | 7 agosto 2013

These are completely normal numbers to see during initial warm up and acceleration during the first few yards of driving. No number you have quoted is out of normal limits. Of course the number settles down once the systems are all warmed up and the car is being driven at a steady speed without further acceleration required. If your instantaneous range on the freeway is "sometimes 400wh/mile" that would give you a total range at freeway speed of sometimes as low as 212 miles. With AC use even not going up a hill that is not far outside the realms of reality from the Model S at freeway speeds.

Brian H | 8 agosto 2013

500kW/hr? The batteries would ignite like flashpaper.

bp | 10 agosto 2013

Yesterday, I did a test to compare the average Wh/mi reading in the trip display (since last charge) and the energy graph - comparing the values at 5, 15 and 30 miles (the three settings for the graph).

The trip display is always higher than the energy graph - so it appears the two displays are using different methods for calculating energy usage.

It's possible the trip display is measuring total energy consumption - while the energy graph is only displaying energy usage while the car is in motion (which could exclude usage while the car is stopped at a charger or at an intersection).

Or there is a problem in the software - and one of the displays really is showing the wrong values.

I've sent an e-mail to ownership on this.

jat | 10 agosto 2013

The maximum efficiency is about 25mph -- below that you are wasting a lot of energy on constant-factor uses, plus the electric motor is generating weak fields that aren't efficient (notice how you don't get any regen when you are rolling really slow? This is the same thing in reverse). If you are driving a gas car, your MPG is extremely low when just idling and letting the car creep forward as well - most of that energy is going to just turning the engine over, not moving the car.

But the short distance you are driving at those speeds means they don't really matter in the overall efficiency.

Dr. Bob Reinke | 14 agosto 2013

My MS is outside at the resort, and before I take it anywhere in the winter I step out and start the heat and seat heaters to reheat the car while it is plugged in. I set the charge amperage between 5 and 10 amps and start the charging by sliding the charge into the "trip" range. Then leaving the door jar at the fist click, the car doesn't know that I am out of the car and it warms the interior and preconditions the battery. I'm not sure why, but if I am delayed for a few minutes on my start, the range available on the 17 inch screen can drop too near 0 even with a full charge and warm battery. Generally the range displayed on the drivers screen is more accurate. I have called Chicago service center and they tell me to go by the range in the speedo display. Guess that the software even with the best perameters isn't as smart as common-sense.