# A couple of questions



## Midnit3 (Oct 8, 2017)

First my battery now charges to 264 at 90 percent when it used to charge to 275. I was told it was the cold weather but even on warming days 60’s.. it;s the same. Tesla ran a battery diagnostic and said all was fine. Thoughts? Second on my account is always listed full self driving as an add on but no longer. It just says enhanced autopilot under options. Is that the way it should read? Thanks.


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## Frully (Aug 30, 2018)

fsd is missing on people's tesla account, it's a glitch.

Range is an estimate. If you haven't balanced your cells (happens in the background) by full charge/discharge a few times, then the bms might be out by a few percent here and there. Totally normal.


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## Midnit3 (Oct 8, 2017)

Thanks! Will letting the battery fully drain then charging it get it fixed?


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## garsh (Apr 4, 2016)

Midnit3 said:


> Thanks! Will letting the battery fully drain then charging it get it fixed?


Probably not if you do it just one time.

Tesla Service appears to recommend charging up to 90%, then letting it go down to 20% several times in a row. This gives the BMS a better ability to learn the actual range of the battery. I suggest clicking the link to the quoted post below, and reading through that thread.



PA_Ray said:


> (Long post) In the fall I posted about a significant drop in range on this thread. Eventually I got hold of tech support who looked at my records and said to schedule a service appointment. About a week before I was contacted by pre-service support and below is clips from what they said:
> ___
> 1. Good afternoon Ray. I am a service technician here with Tesla's virtual service team and have been looking into your concern. I have pulled your vehicles log data and have spent a bit of time reviewing it and running remote tests and analysis on the vehicle, especially the HV pack and related systems. Before we go as far as to bring your vehicle in to the service center here, I'd like to ask you to do a little "home work" with me on this one. I do see that you charge your vehicle very regularly, which is fantastic. However I do see that the HV pack operates within a relatively narrow window of charge (generally 55-85%). This is terrific for battery longevity, but over time it does tend to make the battery "forget" what it is fully capable of. What I would like you to do is extend this window if at all possible. Let the battery go down to @30% or even lower if you feel comfortable with that (using the heat and "dog mode" are handy for this) and let it sit for a few hours (generally 2-3) then charge it back up to 90% and let it sit (plugged in). I'd like for you to do this a few times, like 4 or 5 or even more if at all possible then I'd like to re-run my tests. What this does is allow the battery to remember where the "bottom" is and recalculate what its energy capacity is more accurately.
> I'm going to move your appointment to an "outstanding" status pending the outcome of what we see after this.
> ...


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## Mr. Spacely (Feb 28, 2019)

Never drain your battery all the way to 0...


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## garsh (Apr 4, 2016)

Mr. Spacely said:


> Never drain your battery all the way to 0...


I've done it (well, to 0% anyhow). And I know that Mad Hungarian has done it.
Even Elon says that it shouldn't cause any issues.
But best not to make a habit of it.


__ https://twitter.com/i/web/status/1068745921079345152


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## Achooo (Oct 20, 2018)

garsh said:


> Probably not if you do it just one time.
> 
> Tesla Service appears to recommend charging up to 90%, then letting it go down to 20% several times in a row. This gives the BMS a better ability to learn the actual range of the battery. I suggest clicking the link to the quoted post below, and reading through that thread.


This is an EXCELLENT thread! Thank you for sharing @garsh.


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