CT vs Cold Weather States

[Crissa]

Maybe not the chemistry, but I do think the tab less design will with the lower resistance will

They will produce about the same heat, according to their slides, because the cells are so much larger. The tabless makes the larger cells as efficient as the smaller cells - if you had tabless in the smaller design they would produce less heat.

This won't affect cold weather all that much. Tesla has active heating and cooling through multiple paths already.

-Crissa

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[ajdelange]

It started to drop off below 40 noticeably and a lot in the teens

Something funny there.

Model 3 user here in Colorado Mountains at 8000 ft above sea level, our model 3 (pre heat pump) lost between 15-20% in the coldest of the cold months

This is more normal.

 

[ajdelange]

The CT will have the 4680 cells. You can throw out the window the past experiences, battery behavior will be vastly different

In what way would you expect the performance to be different?

 

[Crissa]

Winter range will vary by:

Storage (Is the car plugged in at night, is it covered, is it inside)
Edition (does it have the newest battery temperature management)
Software (does it have the newest battery temperature management)
Weather (precipitation, wind)
Conditions (snow, slush, vs dry roads)

All of these things reduce winter range.

I have a Zero. It has no temperature management, and is merely covered at night. I've lost up to 60% of my range in winter temperatures (freeway riding below 30F). Usually, though, I just consume 20-30% more due to cold battery and higher wind resistance. I've even had that happen on a cold day in the summer (we had one day where it didn't get over 50 and went to almost freezing at night... The battery never warmed up.)

A Tesla wouldn't have thes issues.

-Crissa

 

[azjohn]

In what way would you expect the performance to be different?

I am thinking about electron flow with the new tabless design.

With the colder weather the energy gets sluggish in the electrolyte and with the lower resistance I am expecting better performance in range. After doing some research on the battery design of the previous cell it is the bottleneck and a big one. They have removed the big tab and replaced with a lot of much smaller tabs that are positioned along cell ribbon/jelly roll

I feel regen, charging and discharging will be enhanced

 

[2Futre4u]

I live in the Colorado Mountains 8000ft above sea level with a 2020 Dual motor Model 3 (AWD), we lost about 10-15% range last year. Our model 3 does not have the new octovalve (battery heater). The range loss was similar to the loss on our ICE vehicles as we have to prestart them to preheat before we drive, the model 3 you grab your phone and start the seat heaters before you get in. The key to not losing too much range is to keep you car charging until you need to leave, this keeps the battery warmer, as well as in a garage if you can (our garage is not insulated, and often below zero degrees, but at least no wind/ snow build up). The car handles great in the snow, until the snow is too deep (same for any car this low) but once snow hits 6-8 inches of depth that flat bottom skid plate acts as a sled (this wont matter for city folks with paved and plowed roads). Long story short, it doesn't lose as much as some would have you think, and it handles great, although I will be adding 4 season tires with snowflake rating this winter, but that is because where we live we either need chains or a tire with the mountain/ snowflake rating to be allowed up the mountain.

 

[ajdelange]

I am thinking about electron flow with the new tabless design.

In the tabless design rather than having all the current flow in the relatively small cross sectional area of the tab it can now spread out over a much larger cross section for much lower current density and this lower internal loss at the connection. Plus, if I understand it correctly, the entire foil edge is connected directly to the terminal so that current from all parts of the foil flows the same distance as opposed to the tabbed design where current from turns inside the roll would have to flow the entire length of the foil to get to the tab and thus out of the cell. This also means less internal resistance which means (1) Less heat lost in charging/discharging (2) Less voltage drop under heavy load.

With the colder weather the energy gets sluggish in the electrolyte

Not sure what you mean here. Energy isn't stored in the electrolyte. It is stored in the LiC bond.

and with the lower resistance I am expecting better performance in range.

Less internal resistance means less loss and that does imply larger range for the same capacity battery. But I don't think that we as drivers are going to see much difference in the way the vehicles drive or charge. Lower resistance means higher charging current with less heat and thus less cooling demand. But there are no Tesla chargers bigger than 250 kW at this point.

I feel regen, charging and discharging will be enhanced

Roger that but I don't think we are going to notice anything too dramatic in those areas.

 

[Crissa]

Not sure what you mean here. Energy isn't stored in the electrolyte. It is stored in the LiC bond.

The electrons travel across the electrolyte, don't they?
This isn't a semiconductor.

-Crissa

 

[ldjessee]

Maybe people will see the vehicles with prototype 4680 cells being tested in the normal Tesla winter testing places? Maybe some information will leak out?

 

[jerhenderson]

Please correct if the following guesses are wrong.

Auto-driving (whatever the level or whatever it's called) responds to white lane-marker lines on the pavement, so a covering of snow would, as suggested, degrade this feature to near


roads get plowed.

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