Car behavior as battery is running out...

Car behavior as battery is running out...

Hi all... Drove from Bethesda MD to NYC today. Things got a little tense toward the end.... I'd stopped at the Supercharger in Delaware, which works great -- charging at 230mph!! I had filled the battery up to about 150 miles for a 120 mile 2nd leg, which I thought would be fine. There was some traffic, rain, 5 passengers, etc.. So my estimated range ticked down a little faster than my actual mileage -- I averaged 350kwh on this leg. And I made it.. With 3 miles of range to spare!

My question / comment is that there was absolutely no notification by the car to tell me to charge up, turn off the a/c, etc... I just couldn't believe that the car didn't seem to care..

I thought I remembered reading in the NY Times article a few months back (the one Elon went out of his way to discredit - successfully) debacle that the car tried at some point to conserve energy... I think there should be some notification to the driver for his own safety..

So -- has anyone else experienced this? Anyone else get a little jittery over it? And what would happen if I ran out of battery?

Thanks in advance for your thoughts.

cloroxbb | September 1, 2013

Other than a light that illuminates "E" on an ICE car, there is no extra warning. If you can't tell that something is wrong, by your miles remaining being almost ZERO...

I mean how much warning do you need? | September 1, 2013

Also the larger power bar changes to amber, and then red as you get to the end. While not recommended to use, there is another 10-15 miles of emergency range available AFTER you reach zero.

nickjhowe | September 1, 2013

@EssDub - I've never it down personally, but I thought the same - at around 15 miles of range I thought it went into lower power mode, a dashed line appeared on the power meter and a warning appeared saying "charge car"

WSE51 | September 1, 2013

I got down to 6 Rated Miles once, and there was a dotted line showing the maximum acceleration (power draw per second) on the meter. It was similar to the dotted line that shows up when you do a Max range charge, in that case it shows the max you can regen. I also recall some warning text coming up to charge immediately.

Tâm | September 1, 2013


I used to own a gasoline car and I never partially filled the tank even though I knew that I could fill only half of it and it would still run over 200 miles.

Somehow, when it comes to Model S, we expect every mile is accurate for their own personal driving situation, not just for laboratory conditions.

Thus, instead of charging it for our personal driving situations, we tend to give it less of a wiggle room.

However, numbers don’t lie, driving range record is 423.5 miles in Florida

Dutch team got a range of 388 miles:

So if we are short of that, that’s because how we drive.

Until "auto-pilot" feature is implemented, you'd better get to know your car.

Like TeslaTap mentioned, you can watch for the visual cues at the battery meter. However, by that time, it might be too late.

I learn quickly to look at my GPS miles to destination and the EPA Rated battery meter and compare them every half hour or so to re-adjust my driving speed as needed.

I always start with a comfortable buffer. In your case, start with a buffer of 30 miles is quite too close (battery meter at 150 miles for a destination of 120 miles=30 mile buffer).


Brian H | September 2, 2013

Maybe the car used GPS to detect it was getting close to home, so no sweat! :)

one2mark | September 2, 2013

Two things... what are you thinking not waiting an extra 15 min to fully charge (1. it's free 2. your destination charger may not be working properly nor is it as fast 3. it is only another 15 min)

The second thing - the car indicates zero miles of range and says charge immediately, just below the speed/battery usage indicator. I ran into this a month or so ago traveling to Raliegh, NC from Charlottesville, VA. The car still continues on for 20-30 miles. The message to charge came on when I used 75KW/hrs of electricity leaving a theoretical 10kw/hrs....although I don't believe that is all available as it will brick at that point (which Tesla won't allow to happen). Lastly using 350wh/mi is not very efficient at all. Like a gas engine car if you run it hard it is not as efficient.

Grant910 | September 2, 2013

I do my planning based upon the percentage of rated range which I can reasonably expect, and I compare it to the GPS distance. For my car and my highway driving habits, it is clearly around 70% when I drive without worrying about the speed, and around 85% when I drive efficiently. In cold weather it is of course worse. This has worked well. I drove NYC to Boston in subfreezing temperature in my 60 kWh, speeding, and 70% was predictive.