4680 cell implications

[azjohn]

Just saw a recent YT video where Sean Mitchell has a guy with a PHD in battery chemistry and he was claiming that he thinks the 4680 cells could be capable of a max charge rate of 1600kw. This would be helpful with the Semi and CT

4680 is bigger but would be able to take a higher amount of power over a longer period of time thus making the charge rate shorter

 

[Swampgator]

Just saw a recent YT video where Sean Mitchell has a guy with a PHD in battery chemistry and he was claiming that he thinks the 4680 cells could be capable of a max charge rate of 1600kw. This would be helpful with the Semi and CT

4680 is bigger but would be able to take a higher amount of power over a longer period of time thus making the charge rate shorter

Watched that too. Was very good. Not sure they will go that high though due to warranty reserves. Even half that would be fantastic.

 

[MP3Mike]

he was claiming that he thinks the 4680 cells could be capable of a max charge rate of 1600kw.

In what size pack? (Certainly not individual cells as that would be ~380,900 amps.) Existing 18650s can charge at 1600kW too, you just have to have a big enough battery pack and enough cooling.

And of course there is the issue that no charger, that is currently available, that supplies more than 350kW.

Edit: That was painful to watch. But he was talking about 1600kW to charge the Semi. The Semi is expected to have about 1,000kWh of battery packs, or ~13x the size of the Model 3/Y LR pack. That would mean to start with you could charge at 13x the rate the Model 3 could or 3,250 kW. So he thinks the 4680s will charge at half the rate of the 2170s. He really doesn't appear to know what he is talking about.

 

[Lloyd]

Since heat is not as much of an issue, we could see a reduction in the charge taper. Think how fast you could charge with full power over the entire charging event!

 

[mark95476]

I predict a near future "problem" people will be complaining about when the 4680 cell-based vehicles are in production:
"My Tesla charges too quickly and I'm getting dinged for Supercharger idle fees before I'm finished in the restroom."

 

[Rocky_H]

I predict a near future "problem" people will be complaining about when the 4680 cell-based vehicles are in production:
"My Tesla charges too quickly and I'm getting dinged for Supercharger idle fees before I'm finished in the restroom."

That's not the future--I've already seen that thread about the Model 3.

 

[swengl]

That's not the future--I've already seen that thread about the Model 3.

Honestly, I'm OK with this. When you park at a gas pump, the most courteous thing to do is pull up before going inside to grab snack/hit the restroom. It's not cool to block a pump/charger if you are done fueling. Teslas tell you how long you need to charge, act appropriately.

 

[Feathermerchan]

It is important to remember that the 4680 cell was presented with many advantages and not just one or two. The graph near the top of this thread actually had an animation. It showed what the charge rate would be if they just scaled the tabbed 2170 to 4680. The 4680 cell has about 5X the capacity of the 2170 to to charge one at the same rate as a 2170 would take 5 times the current. But a scaled up 2170 would still have one tab and so the current flow would cause the cell terminal voltage to reach 4.2V very quickly requiring the charger to reduce output and increase charge time. Because of the tabbed construction, the 46880 can be charged at about the same rate (5X current of a 2170) so charge time is about unaffected.
But remember that you only need 1/5 as many cells which makes the pack cheaper, quicker to build and test, and lighter. The Model 3 and Y packs have 46 2170's in parallel and 96 blocks of those in series for a total of 4,416 cells. The 4680 pack will then have about 883 cells.
These are all big advantages. Musk also said that you could get more power (kW) from the cell. With the lower resistance (than the equivalent capacity 2170 cells) you will get a range increase because less heat will be generated when discharging the new cells. Heat not generated during discharge means more energy sent to the drivetrain. For that same reason charging may be a little faster. It's pretty fast already and I don't think it needs to be as fast as gassing up your ICE. Why? 90% of the time or more you'll be charging at home.

 

[mark95476]

Tesla has to cue up a first world problems meme...

That's not the future--I've already seen that thread about the Model 3.

 

[dazedNconfuzed]

Growing concern: longevity.

There's much said about the "million mile lifespan" of the new batteries, but I'm noticing silence on temporal lifespan.
I probably have a million miles of driving left on _my_ lifespan; I'm wondering if the battery will just self-destruct well before my decades-hence demise.

If the power pack doesn't meaningfully degrade over the next 30 years, a TriCT might just be my last vehicle. If it does, it's going to die long before 1,000,000 miles (impacting the total cost of ownership badly).

Core problem isn't just that the batteries presumably degrade over time regardless of use, it's that (apparently) they'll be epoxied into the frame and practically impossible to replace/repair.

Thoughts? Insights?

 

[CyberGus]

Core problem isn't just that the batteries presumably degrade over time regardless of use, it's that (apparently) they'll be epoxied into the frame and practically impossible to replace/repair...

I got the impression that the battery pack would use epoxy internally between the cells, but that the pack itself would be bolted to the underside. It would add stiffness, and therefore allow for reducing the frame strength, but it would still be removable (and you're not going to drive around without the battery pack lol).

Even the current battery pack is unserviceable.

 

[mongo]

I got the impression that the battery pack would use epoxy internally between the cells, but that the pack itself would be bolted to the underside. It would add stiffness, and therefore allow for reducing the frame strength, but it would still be removable (and you're not going to drive around without the battery pack lol).

Even the current battery pack is unserviceable.

The presentation looked like the pack was the underside (and center cast section of the vehicle) which aligns to comments Elon made previously about extra material (pack top, then floor pan).

 

[CyberGus]

 

[Feathermerchan]

I agree that the pack can be made to bolt in.
And I agree that the current (pun) battery pack is unserviceable.

 

[Swampgator]

Growing concern: longevity.

There's much said about the "million mile lifespan" of the new batteries, but I'm noticing silence on temporal lifespan.
I probably have a million miles of driving left on _my_ lifespan; I'm wondering if the battery will just self-destruct well before my decades-hence demise.

If the power pack doesn't meaningfully degrade over the next 30 years, a TriCT might just be my last vehicle. If it does, it's going to die long before 1,000,000 miles (impacting the total cost of ownership badly).

Core problem isn't just that the batteries presumably degrade over time regardless of use, it's that (apparently) they'll be epoxied into the frame and practically impossible to replace/repair.

Thoughts? Insights?

They already have the chemistry to make it over 300-500,000 miles. Why would they go backwards? My take is that the decreased resistance will lead to higher COI for greater cycles, not less.

 

[dazedNconfuzed]

It’s not distance (power cycling) that’s concerning me, it’s calendar lifespan. Lithium batteries are noted for having a limited temporal lifespan. A million mile battery would take me ~40 years to drive out, but will it last >10 years?

 

[Swampgator]

It’s not distance (power cycling) that’s concerning me, it’s calendar lifespan. Lithium batteries are noted for having a limited temporal lifespan. A million mile battery would take me ~40 years to drive out, but will it last >10 years?

Cell/pack degradation is a direct result of number of cycles and storage temperature.
If stored at o[optimal temperature Li Ion cells would outlast you if they are only cycled at low numbers.

 

[Feathermerchan]

Two examples.
One - I have a Sony 8mm camera. Not digital. I have tapes back to 1987. I charged the battery a few weeks ago and it still works. Really surprised me.
Two - I fly electric model airplanes. I stopped flying for several years. I 'store charge' my batteries. That is about 60% charge.
I took a few planes out the other day and the batteries performed normally.

 

[mark95476]

It looks like Model S Plaid will be first to have the new 4680 cells. Specs look phenomenal with 520+ miles of range, ridiculous acceleration ...etc..

Oh yeah, Model S and Model X with 18650-based cells/packs have lasted for 100,000s of miles. Tesla's cells/packs are only getting better.

 

[azjohn]

IMO the present batteries can last 1 million miles based on charging cycles, the LFP batteries will have the best life