"Hot charging" could charge an EV 80% in ten minutes and prolong lifespan to 1700 cycles

[DaveinOlyWA]

So no one sees a problem with repeated rapid super heating and cooling of the packs?

Its bad enough to have to suffer thru the translation (guessing original article was not in English... "shrinking the pack??") but what is worse is getting a non technical view of a likely very technical process.

 

[danrjones]

So no one sees a problem with repeated rapid super heating and cooling of the packs?

Its bad enough to have to suffer thru the translation (guessing original article was not in English... "shrinking the pack??") but what is worse is getting a non technical view of a likely very technical process.

I think that depends on the pack chemistry. Some of the chemistry I've seen reports that they are working on don't mind heat as much.
The billions being tossed at battery tech now is going to lead to breakthroughs. Who knows which ones.
Tesla seems to be a believer in dry electrode technology from Maxwell, and in the longer term a full dry cell might be possible. .

 

[DougWantsALeaf]

It does seem that 50C is no longer a bad number. Even in the new Leaf Packs, it doesn't seem to take much of a toll.

 

[danrjones]

It does seem that 50C is no longer a bad number. Even in the new Leaf Packs, it doesn't seem to take much of a toll.

As I tell my wife, I suspect the pace of change for EV batteries is going to be fast a furious the next two decades.
Separating rumor from fact, and vaporware from what really materializes will be difficult.
The next two decades could be to batteries and autonomy what the 80's and 90's were to the PC.

A month ago nobody believed Tesla was going to shift to Prismatic cells. But yes they are, at least for China.
They also may be getting rid of Cobalt.

This is to say nothing for Maxwell and dry electrodes, or any of the other longer term changes.
Or other companies.


As to the Leaf, time well tell. I still think my car is going to plunge into the upper 80s SOH this summer.
I do know HEAT last summer caused my SOH to go south and my HX to go north. My next 3 month update is in about a week.

 

[palmermd]

Because being able to move that much heat in an hour isn't something that is going to fit in a car. The car could heat it up its own battery that fast with resistance heaters but you would need an air conditioner almost the size of a car to cool it down in 10 minutes.

The Model 3 can reportedly maintain a speed of ~130 mph until the pack is empty. If its efficiency at 130 mph is 700 Wh/mile, its continuous power consumption is about 91 kW, and it thus has a heat rejection capacity (from resistive heating in the pack, not including motor) of at least 4600 W. Add in the heat generated by the motor (around 85-90% efficiency at 91 kW?) and you get around 15 kW total heat rejection. Taking that value from a linear point of view (obviously conductive temperature change isn't linear with time) it should only take around 20 minutes to take 3 kWh out of a hot pack with today's Model 3 TMS.

700 Wh/mile * 130 mph = 91 kWh/h = 91 kW.
I = 91 kW / 355V = 256 A.
M3LR pack R = 0.03 ohms / 42p * 96s = 0.07 ohms.
Heat power = (256 A)^2 * 0.07 ohms = 4.6 kW

Moreover, the Model 3 can reject that much heat while maintaining a battery temperature less than 45°C, regardless of ambient. Since conductive heat exchange is roughly linear with the difference in temperature, it should be substantially easier to cool off a pack at 60°C to 30°C, and in fact the Penn State research suggests cooling is 8-12x as efficient at higher temperatures.

So, in my view, achieving "hot charging" without long cooldown periods is more about tweaking coolant flow rates and radiator fan speeds on e.g. a Model 3 rather than a complete reinvention of the battery.

Tesla already does this if your route includes a stop at a supercharger. I've seen it happen on every long trip that has a scheduled stop. https://www.reddit.com/r/TeslaLounge/comments/c47r03/preconditioning_battery_for_supercharging/

 

[Nubo]

As I tell my wife, I suspect the pace of change for EV batteries is going to be fast a furious the next two decades.
Separating rumor from fact, and vaporware from what really materializes will be difficult. ...

Some things never change

Just as soon as a man gets working on the secondary [rechargeable] battery it brings out his latent capacity for lying.

 

[Anonymous]

Tesla already does this if your route includes a stop at a supercharger. I've seen it happen on every long trip that has a scheduled stop. https://www.reddit.com/r/TeslaLounge/comments/c47r03/preconditioning_battery_for_supercharging/

They're halfway there. 250kW at 45 degrees C for a 3LR isn't quite 400 kW at 60C.

 

[johnlocke]

It does seem that 50C is no longer a bad number. Even in the new Leaf Packs, it doesn't seem to take much of a toll.

As I tell my wife, I suspect the pace of change for EV batteries is going to be fast a furious the next two decades.
Separating rumor from fact, and vaporware from what really materializes will be difficult.
The next two decades could be to batteries and autonomy what the 80's and 90's were to the PC.

A month ago nobody believed Tesla was going to shift to Prismatic cells. But yes they are, at least for China.
They also may be getting rid of Cobalt.

This is to say nothing for Maxwell and dry electrodes, or any of the other longer term changes.
Or other companies.


As to the Leaf, time well tell. I still think my car is going to plunge into the upper 80s SOH this summer.
I do know HEAT last summer caused my SOH to go south and my HX to go north. My next 3 month update is in about a week.

Keep in mind the the Chinese designed version Tesla is going to be a smaller car with only a 150 mile range and a targeted price of $25000. The Model 3 will eventually get prismatic cells as well with LFP chemistry. No cobalt in the cells will lower costs by 25%. The major question is whether the LFP cells will be as energy dense as NCA cells or will the Chinese Model 3 with an LFP battery have a lower range and a lower price? There are no current plans to switch US built Model 3's to LFP cells but I'd wait until Battery Day in April to see what Elon is up to!

 

[Oilpan4]

No slave mined cobalt is good.

 

[Anonymous]

Given that the main feature of hot charging / asymmetric temperature modulation is improved mobility of lithium ions, it should work with any lithium chemistry (e.g. LFP).