Charging Tesla

Charging Tesla

With Elon’s Post about charging to 90-95%, what about the other end......should you use the car until the battery gets to a certain level before charging? Frequency?

Earl and Nagin ... | April 17, 2019

at the bottom: don't leave it below about 10 - 20% for very long.

jordanrichard | April 17, 2019

What post by Elon about charging to 90-95% ? I know that he had previously Tweeted about the whole ideal charging level of 70% and that event 80% is just fine. Don't recall any Tweets about charging to 95%. One shouldn't be charging to 95% and let the car sit there.

Micpad | April 17, 2019

Elon Musk explains why you shouldn't charge your Tesla battery to 100%

jordanrichard | April 18, 2019

That would be IMHO the other reason to not charge to 100%, but the main reason is you shouldn’t leave the batteries sitting at 100%, in net effect, cooking.

EVRider | April 19, 2019

@Micpad: The 90-95% charging recommendation in the article was for a particular owner who needed extra range. 90% is the recommended maximum for most people.

nothotpocket | April 19, 2019

Nightly charging of 80%-90% is recommended. No problem taking it down under 5%, but don't see that there's a mention of any benefit in doing so.

jordanrichard | April 20, 2019

Um, I woldn’t take the pack down to 5%.

Frank99 | April 20, 2019

I take it down below 5% on road trips all the time with no worries - well, perhaps a bit of range anxiety when the MCU shows that I'll get to the next supercharger with 3 miles of range left. It's so tough to make that decision to slow down to the speed limit.

Speaking of generic Lithium Ion batteries (because the technical details of Tesla's precise chemistry are few), low state of charge isn't a problem. The chemistry is perfectly happy down to 3.0V per cell (Note that fully-charged is about 4.2V per cell), which is likely where Tesla's Battery Management System sets the 0% level. Tesla's BMS is sophisticated enough that they may even be letting the cells drop down to 2.8V or so. If the battery is allowed to discharge below this, the cell voltage rapidly drops to zero, and that's where some irreversible chemical reactions occur that cause battery damage. The main issue with discharging the batteries to the BMS 0% level is that, if you leave them at that state of charge, the car is unable to heat the pack if the temperatures drop, or cool the pack if the temperatures rise, or keep the computer alive to respond to you walking up to the car, etc, because all those actions would discharge the battery pack further, towards the point that it could be damaged. And if you left the car for months at 0%, the cells will self-discharge to some extent, once again dropping the voltage towards the damage level.

So, IMHO, feel free to discharge the battery as low as you feel comfortable, all the way down to a displayed 0% if you wish. But, make sure to charge as soon as possible once you get down to that level because certain aspects of the car NEED power available from the batteries.

Russell.K.Smith | April 22, 2019

i am planning a trip, it would be nice if the web site could be changed to 90% on each car including the SR model 3