Battery charging in cold weather question

[mongo]

ok wow ive never noticed that but im not charging at home neither only at a supercharger. So your saying your battery set it to 72% and then you manually chsrged it for 90 more minutes and precondition got it to 80%?

also well the CT reach a full 80% charge when the weather breaks and gets warm again?

The charge limit was set to 80 and the vehicle had charged to there.
Then the temperature dropped and time passed.
So the pack was at 77% with a 5% cold derating and the UI showed 72%.
I activated climate control and 90 minutes later, it had added 3kWh net to the pack to get it to 80% with 1% cold offset, so reading 79%.

So it was always charging to 80%, but that doesn't account for cold adjustment and the UI won't necessarily read 80%. Same deal with Superchargers.

Sponsored

 

[mjames06]

The read out says 73%, but the look at the bar graph it will be at ~80, with 7% blue unavailable energy.
Here's mine from this morning , 72% but really 77% with 5% blue.
After 90 minutes of preconditioning and charging, it got up to 80% with 1% blue.

I s now paid attention and this does not happen at all. How you get the blue bar i have no idea

 

[mongo]

I s now paid attention and this does not happen at all. How you get the blue bar i have no idea

It should show up in the app when the pack is cold
Stale data:

After waking the truck, 79% reported, 1% blue, 80% total:

 

[Tallgeese179]

I primarily charge for free at work, but for the holiday break and random weekend charge maintenance I wanted to max out my charge potential for my exterior 20A outlet so I ordered the NEMA 15-20 plug from Tesla. Might not seem like much, but it's around a 50% bump power.

It's been doing a fine job of maintaining my truck in the 60-80% range after daily errands in Pittsburgh. Charging at 120V is pretty inefficient though and the projected charge time will definitely be wrong (12 Hours turns into more like 16-24 when it's in the 20s outside). However it does the job and allows less of the battery charge to be wasted on morning pre-conditioning.

Link to the adapter: https://shop.tesla.com/product/gen-2-nema-adapters?sku=1104932-10-B

 

[PungoteagueDave]

You should not lose 60% in a week, especially if you turn on low power mode.
If you arrive with 80%, you might be better off not plugging in. If the pack gets cold, then loses charge, then turns on charging, the 120V charging might not be sufficient to heat the pack resulting in less energy than not charging at all.

This is correct. I have experienced two times where 110v connection resulted in lost range during attempted charging. At low temps (both times below 0 F in my case) the battery will not accept a charge until warmed to a specific level. At extreme temps and a level one charge source there’s not enough power to achieve charging temperature. The charger will use battery to warm itself before switching over to the grid supply, netting a loss. I’ve watched range decline numerous times while attempting to charge even on a level 2 20-amp charger at a ski resort with temps in single digits. With level 2 it eventually got to needed temp and began accepting charge. With level one that never happened and charging netted a loss. The bottom line is that level one charging doesn’t work at extreme low temps and can cause range loss.

 

[mongo]

This is correct. I have experienced two times where 110v connection resulted in lost range during attempted charging. At low temps (both times below 0 F in my case) the battery will not accept a charge until warmed to a specific level. At extreme temps and a level one charge source there’s not enough power to achieve charging temperature. The charger will use battery to warm itself before switching over to the grid supply, netting a loss. I’ve watched range decline numerous times while attempting to charge even on a level 2 20-amp charger at a ski resort with temps in single digits. With level 2 it eventually got to needed temp and began accepting charge. With level one that never happened and charging netted a loss. The bottom line is that level one charging doesn’t work at extreme low temps and can cause range loss.

Based on my testing with a 48A Wall Connector, it will pull from grid when cold, but it also pulls from pack (versus ignoring grid), maybe charge supply limit changes behavior?

Sponsored