3 year old Model X battery problem

3 year old Model X battery problem

My 3 year old model X (70D) is 66000 miles. Its battery doesn't hold power as good lately. The most noticeable part is when the power reserve is under 50 miles, the car can actually go <20 miles. When the car is parked and the battery reserve is under 20 (such as 18 miles), the battery reserve will drop to zero within two hours for no reason. It happened many times. I went to Tesla appointment yesterday, and was turned back home because they said to diagnose it remotely. They did the test, and emailed me that everything is normal. How can this be normal when I lose 25% confidence (<50 mile out of 200) for a car that I spend nearly $100k only a few years ago? Do you have similar problems? Any suggestions? Thanks, happy New Year!

eding00 | 03/01/2020

By the way, I live in San Diego, the weather was not an issue. it was 70 degree and sunny yesterday, the car's power reserve dropped to zero from 17 miles within 2 hours in the afternoon when parked under shade. | 03/01/2020

Yep, this has been reported as normal in any EV. When you get to low states of charge, it will get you there in the range indicated so long as you continue driving, but if you stop, it can go to zero very quickly - especially in the cold. I don't think this has anything to do with battery age. Sounds like you like living on the edge if you regularly get down to 20 miles of range.

One possible explanation is when you power on the car after turning it off at low SOC, the battery heater and cabin heater all come on to max power and that drops the battery voltage to be sensed at 0% SOC. As long as you know how this works you can avoid it by not running the battery so low and then powering off and letting the car cool down. | 03/01/2020

I should point out that the battery heater may come on even at 60F, as the battery likes to be warmer. It may also be the A/C turning on if the car was above the temp setting, which is also a significant drain and can cause a similar situation.

eding00 | 03/01/2020

OK, Tesla, got it, you made my day. We usually charge it around 60. It just happened that we used it close to 20 recently, and noticed the problem.

eding00 | 03/01/2020

Is there anyway to totally turn off the car when parked? why the heater need to be on when car is off?

One more suggestion, if you put your above explanation in the diagnosis report, it will have much better reaction from customers, compared to only telling me everything is normal, while I am puzzled and suspect Tesla service didn't do their jobs...

Bighorn | 03/01/2020

Energy may be drawn to condition the battery temperature after parking, more likely cooling in your case. Take home is to not park with low SOC.

Bighorn | 03/01/2020

Range mode is known to keep the battery heater from coming on, so that would be a possible approach to mitigate the losses.

eding00 | 03/01/2020

Thanks, Bighorn, good to know. | 03/01/2020

@eding00 - I'd also suggest charging to 80% or 90%. Charging to 60 (60% o 60 miles?) doesn't leave much buffer. It's also better for battery longevity to be charging to a higher level and not going near zero. Just like a gas car, most rarely let it go down to less than a gallon of gas. You can do it, but you're risking running out of fuel unexpectedly.

mathwhiz | 03/01/2020

Yep, Range Mode should inhibit the battery heater...

@TT ... I interpreted the statement, "We usually charge it around 60..." to mean they charge the battery when it's depleted to around 60 miles range (OP, please clarify). This suggests holding off charging until the battery is at a low range SOC. This is not a practice I would recommend.

But I must stress that the battery really shouldn't be left with a SOC as low as 20 (or less) miles - it should be charging...

Just my 2¢.

jimglas | 03/01/2020

Bighorn is always right

Triggerplz | 03/01/2020

Jimglas is always right about Bighorn being always right :-)

mozzecsite | 03/01/2020

I think you need to replace your battery

mbirnie51 | 04/01/2020

@eding00: First, please state your configuration of the vehicle fully, such as year/month of build, battery size, mileage on odo, tire size, and software you're running. Also, you're lifetime wh/mile helps in giving you some of our insight. 1) As suggested, RANGE MODE will keep battery drain lower than not using RM. 2) Did you disable SENTRY MODE at your home location as this is a big drain too; and you can disable SM when you park away from home if your going to park for a couple of hours, that will save range too. 3) If you have a home charger, it sure helps your battery life to charge each night setting your charge limit to about 80%. I set my amperage rate at 10 AMPS and limit to 80% to keep current flowing for many hours, keeping the battery warm when I need to drive it. 4) If you know when you will leave in the morning, pre-condition your vehicle while it's plugged in and charging, this will help in your lifetime wh/m because you won't start out cold and drain your battery using high amperage consumption.

Most folks here are more than willing to help anyone with their concerns, and there are millions of EV miles of experience to tap into.

hoffenberg | 06/01/2020

Such helpful information here. i always learn something new. is there any downside to range mode?

Bighorn | 06/01/2020

With battery heating disabled, in cold environments, it will take significantly longer to get warm enough for full regen and sometimes full power.

pctooling | 02/02/2020

Do you know the battery made before 2016 and battery early 2016 have artificial capping of charging and cap for maximum Kw/h .Tesla used it to prevent battery fire.Software 2019.16.X.My maximum charge was reduced from 90Kw to 73Kw.Each cell was reduce .I am planning to take them to court.No one know and Tesla know they are dawn grating the vehicles without permission. I have less power ,my range reduced, charging more 2x weekly.
I try to contact service and all I hear it is my driving and it is same or better after 4 years.Good luck