I'd be very interested in seeing what they can provide for us. Improved battery chemistry for use in the far north is of far, far more value than yet another 5 person car for 1 person driving in San Francisco.
Exactly! That sounds like a drawback when you state it like that, but what it actually means is that this magic battery doodad needs to provide 90-95% of the performance of its existing, mature competitor (assuming no other drawbacks) just to be break-even in the market. You don't disrupt markets with numbers like that.
The problem is mostly that it does the battery draw when parked.
Solid electrolytes are coming some day soon, so that we can let it freeze without killing the cells.
Right now, the Tesla is hard to use in a winter sport season unless where you're driving has a charger or underground parking near a plug point.
I can drive up hill to a nice ski resort, spend 3+ days taking the bus with all your shoes on without touching the car.
With the batteries, they'll just run down when parked, so I cannot park it for a whole week outdoors like I can do with my Subaru.
And with the low battery + low temps, it will not charge back up going downhill so the expected range drops massively by the time you're downhill.
Once you navigate to a charger, the car starts running the heater and driving down range further.
Watching the car battery eating its own range while driving to "Donner pass road" on your way out of Tahoe or Reno feels rather appropriately horrific.
What kind of clunkers have you been using that lose charge on the 12 volt after just 3 days in the cold? I've occasionally left my ICE car out in the cold for a week without using it and it never once even crossed my mind to worry about whether it would start after that; I've never had that issue on any car built in the last 15 years.
I wonder if regen braking going to zero is behind some of the horror stories of sudden unexpected range loss in cold temps.
Ideally, you don't do that, but when traveling sometimes you have to stay at a place that doesn't have a charger, and it's really cold, and now rather than a 30 minute charge it's more like 90 minutes.
That’s false since at latest 2013 in the US.
The past 12 years of BMW as a counterexample all have thermal management. Tesla too.
You may be remembering the original Nissan Leaf?
I believe the eGolf which was sold in the US shares the same drivetrain and battery.
Perhaps you are changing the topic from your original thermal management to heat pump systems specifically?
> This is one of those Great New Technology items that smells like a failure simply because it's not competing with the thing the designers think it is.
This technology makes no sense for fast DC charging because there's enough waste heat to keep up the battery temperature, and you can just use some of the power to heat up the battery.
But it can help for slow overnight charging. Keeping battery heated all night is wasteful, but you still want to be able to charge.
The BMW i3 had inductive heating strips underneath the coolant channels in the battery pack[1]. I know our i3 had a heat pump, I presume both were in play.
We used our i3 down to -25C (-13F) many times, didn't have any issues.
You can’t just overvolt out of that - you need an external source of heat until you’re out of the dangerous thermal area.
The charge currents for sub-zero are near zero amps, but are still > 0. It should destroy the cell, but apparently doesn’t?
Any insight?
At least not in a way that people complain about battery failures or degradation. On the other hand, the battery has to reach that temperature in the first place, which may take a couple days of constant exposure to that temperature.
I did some research, and the plating issue happens when charge currents exceed the ability for the battery to absorb them, which dramatically decreases below freezing.
That is why those battery charts show dramatically reduced charge currents (nearly zero) when around freezing.
That data sheet also doesn’t cover cell life in these conditions conditions.
They have very high normal C ratings (hundreds of amps) which is why it is measurable and not actually zero, but reducing it to a couple amps before failure isn’t much different.
If batteries aren’t failing in these conditions, it’s because of some other protective circuit, not because the battery itself is special. It isn’t.
Edit: downvote me all you want, I was responding specifically to “It has to beat a battery with a garden variety heat pump attached” of which EV heat pumps are not garden variety heat pumps, which do struggle at those temperatures. Didn’t think I had to be so pedantic.
The real benefit, in my view, to being able to charge at cold temps is to improve overall efficiency. If you have to waste some amount of power to heat the battery then that is power that could have been used to charge the car instead...
It's true that there are very cold environments (Fairbanks winters, say) where in-car thermal management won't be sufficient to keep charging rates high. But those are the same environments where you can't even start a gasoline car without an engine block heater, and I don't see many "no cars in Alaska" arguments on the internet. Everything has limits, but I don't see this battery trickery having much of a home.
Gasoline powered engines work just fine in these temperatures, although many cars come with auto ignition systems that start up the engine periodically throughout the night to keep it warm. Otherwise you might have to warm it yourself in the morning using a gasoline powered "torch" (or whatever it's called), which sometimes ends up with the car going up in flames.
So it's honestly pretty funny to read that EV work "down to -10°C". Although probably relatively few of us are desperate enough to be living in such conditions.
And in places like Fairbanks where -40 (F/C) is fairly common in the winter, even cars that merely have an engine block heater will have trouble. You need even more heating pads for the rest of the stuff under the hood of you want to keep a car reliable and healthy in that kind of climate.
Now when you move just a bit off the sea, the continental climate kicks in, and you have weeks of -15 -- -20C.
On discharging lithium chemistries at those temperatures or "easily overcame with resistive" let me say that: you just don't know what you are talking about.
Some do but don't enable it immediately, but do so with a software upgrade. (such as what happened with Kia EV6/Hyundai Ioniq 5)
This is one of those Great New Technology items that smells like a failure simply because it's not competing with the thing the designers think it is. It's not enough for this to beat a cold battery with a performance delta ("5x", per the article) that would justify its additional cost. It has to beat a battery with a garden variety heat pump attached, which is a much (much) lower cost barrier.