From 7% to 0% while parked an hour

From 7% to 0% while parked an hour

On my way home Saturday afternoon, Tesla nav indicated I would arrive with an estimated 7% charge remaining. I stopped at my kid's soccer game for a little over an hour, which was about 6 miles from home. On returning to the car with kids in tow, I was dismayed to find the charge display now showed solid red and indicated only 4 more miles of estimated range, and the display on the nav now read that I did not have enough charge to make it home.

The weather was mild, maybe about 68 degrees, not particularly windy. I have not experienced any other unusual battery charge loss recently, and my 2017 MS (about 28k miles) was serviced two months ago.

Any idea why this happened? And thoughts on how to prevent this? Are there certain settings that need to be adjusted in order to park for a short period of time if you need to maintain a certainly level of battery charge?

Thanks as always for any advice.

jordanrichard | May 20, 2019

Don’t let the car get down that low. I am not trying to be a smart ass, but you didn’t leave much of a buffer. Also you mention percentage in one sentence but then quoted miles in another.

How many miles is 7% for your battery. This would give us a better idea of how many miles you lost.

ellis4372 | May 20, 2019

Help! I have a related problem. Model S was apparently not hooked up properly in the garage while I was away and consequently not charging for approximately two months and as a result the battery is completely dead, as in 0 miles driving range and no large screen display. Plugged in cable (properly I believe this time as the blue light comes on) but it is not charging. Am currently trying to plug into a 110 outlet to see if that makes any difference. I may have to have the car towed to the nearest service center.

kerryglittle | May 20, 2019

110 will take forever to charge. If you don't see any miles added in a day you might have a problem. At least the light was flashing on your charger. I hope thats a good sign that it wasn't completely drained. Maybe Tesla has a bit of a buffer to prevent complete draining of the battery. Call your SC and see what they say. Let us know how you make out.

TexByTheSea | May 20, 2019

@jordanrichard - normally I always rely on the mileage estimates and not percentages, but since it showed I had plenty to get home and I was only about six miles away, I didn't take note of the exact estimated miles I had left when I parked. But on average my 90% daily charge (75D with 21" rims) usually gives an estimated 210 miles, so the 7% charge probably meant about 15 estimated miles - but that is the amount nav telling me I would have left once I arrived at my final destination, so I probably had 20-25 miles left when I parked. Was just surprised to see the car go "from no problem getting home with 7% to spare" to "no chance you are getting home" after being parked only an hour.

@ellis - I do know that leaving you car parked long term, the battery does die a couple of miles every day, I would think leaving it on a 110 overnight should enable you to at least boot the car back up with a few miles of charge on it.

DonS | May 20, 2019

Lithium ion batteries have level voltage across most of the charge range, so the battery meter estimates charge percentage by counting electrons flowing in and out of the battery. Note the word "estimate." When the battery state of charge gets really low, then the voltage drops off and the battery meter "knows" it is almost empty.

I hear of people driving well below 0% and others running out with a few percent left. Just because the display is digital, do not expect it to be as accurate as as the numbers might suggest.

Silver2K | May 20, 2019

Happened to me also.

Went from 22 miles to 10 in an hr.

Had mobile tech connect to my car and check logs. He saw my fan turn off when I got out. No indication why till now, but 12.1.1 is extremely buggy. Even my volume is freaking out!

inconel | May 20, 2019

When I parked with SOC below 40 miles there is an alert message on the screen telling me to Charge Now or there might not be enough charge when I return. Do you also see this message?

inconel | May 20, 2019

And I did notice the drop after leaving the car for a few hours is indeed much more when SOC is low. With 200 miles left the drop might be 2 or 3 miles, but with 40 miles left the drop can be 20 miles.

Tropopause | May 20, 2019

LikeTesla YouTube video showed a rental Tesla that was stolen from Canada, put on a ship to Italy, enroute to the Middle East for black market. Law enforcement intercepted the car upon docking in Italy. Battery was at 0% for 6 months or so. 12 volt was fine, car charged up and inspected by Tesla- no problems, no battery degradation.

The vehicle is designed to go into self-preservation mode when the battery gets near 0% to prevent damage to itself. Looks like it works.

Silver2K | May 20, 2019

Never got that message. Never had that type of drop either.

radio | May 20, 2019

Had the same surprising experience after a long and fast drive. From what I read and understand the battery was warm and hence held more energy (showing a about 25 km typical range). After parking for 2 hours the temperature had dissipated a my range was close to 0. Since then I avoid this situation (fast drive followed by a long stopover in cold weather).

tes-s | May 20, 2019

Have Tesla service check your battery. My guess is it is fine.

spineeric | May 20, 2019

@TexByTheSea....perhaps you had 7 miles remaining instead of 7% when you stopped? Although dropping 3 miles in one hour does seem crazy. By any chance was your fob in a pocket that might have had a button pressed during the time you were watching the soccer game? If your fob was constantly communicating with your car, would that be enough to use 3 miles of range? If you're certain you had 7%, then something might be wrong for you to lose more than 10 miles in 1 hour. I lose 4 miles a day with my car just sitting in the garage.

p.c.mcavoy | May 21, 2019

@TexByTheSea - I've observed this type of behavior on a few occasions and also in the situation where I've driven the car for 2-3 hours, battery was fully warm, park the car with battery in the 10-15% SOC range, and then let it sit for anywhere 1-5 hours. This appears to be much more noticeable when the battery is at a low SOC, <15%, than at an elevated SOC. It doesn't need to be really cold temps, but as you stated, may just be case of parking the car in 60-70F ambient conditions and the battery temperature cools down from the operating temps it reaches during a longer drive.

I agree with comment by @radio that it's a response to the battery temperature dropping. This really isn't a case of large vampire drain and lots of energy having been consumed, but more that the BMS algorithm infers due to SOC and temperature conditions that the available energy that can be delivered by the battery has reduced.

Silver2K | May 21, 2019

I have never ever seen that behavior after driving over 180k miles. This started after the latest firmware install.

p.c.mcavoy | May 21, 2019

@Silver2K - I’ve seen this much before the latest update. I actually captured it in a data log via VisibleTesla back last summer. It was a sudden drop between two data points, logged 30 minutes apart, while the car was parked after a ~100 mile cross-country drive. It was that behavior where I saw the sudden drop that leads me to a view that it’s likely crossing some threshold in the BMS calculation algorithm, not an actual vampire drain type of response.

It would take some digging to find them, but I’ve made observations on this forum about that observation.

Earl and Nagin ... | May 21, 2019

The moral of this story is that if you get down to less than 10% SoC, you should plug in as soon as possible since. There is nothing new about this.
Thanks to the OP for the new reminder of this.
Battery behavior close to empty is hard to predict since 0% is determined by the weakest of the ~7,000 cells in the battery.
That we're suspecting different behavior from newer firmware hints that Tesla is working to improve their ability to predict it but we're probably not there yet. The only thing a driver can do today is to not let it go below 10% unless you're on you way to a charger.

TexByTheSea | May 22, 2019

If you do have to park with less than 10% remaining, are there steps you can take to minimize a further loss of charge? Maybe turn on range mode and/or turn off the climate conditioning? Things to do to ensure the car is in the using the least amount of battery possible while parked?

@spineeric - good thoughts but I am sure I had more than 7% charge left when I parked because it was the nav telling me I would arrive at my final destination (at home, not just where I stopped on the way) with 7% charge remaining. So when I parked I didn't think twice about checking the actual range in miles since I thought it was clear I'd get the rest of the way with plenty to spare.

A bit frustrating since this effectively takes out the last 10% of range for any daily errands, if you can only count on that last 10% if you are continuously driving.

Silver2K | May 22, 2019

Climate control will not activate below 20% SOC.

PBEndo | May 22, 2019

I had a dramatic loss of range after a long highway drive on a hot day I forget the exact numbers but I parked with roughly 50 miles of range left about 20 miles from the nearest Supercharger. Within 20 minutes or so of being parked range dropped to 30 miles and I started to panic. Tesla HQ said it was due to the energy used by the battery cooling system.

ellis4372 | May 22, 2019

Regarding my previous post regarding my parked Model S showing 0 miles driving distance, I ended up calling Tesla roadside assistance who came and recharged the 12 volt battery, enabling the computer screen to come on. This allowed me to reprogram the scheduled charging time from midnight to immediately, solving the problem. Glad a tow was not necessary.