While the technology may be advantageous, it seems weird to write a whole article about it without mentioning the obvious solution: Just Heat The Battery. It's true that many early EVs (and most non-Teslas even today) don't ship with battery thermal management. But they won't be getting new battery chemistry either.
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.
My 2022 Volkswagen e-Up has zero thermal management of the battery, it's completely passively cooled with no heating. Not that it really matters, people have tested it and charging speed only starts to degrade after 3-4 rapid charges in one day, with "rapid" in quotes(in tops out at 40kW).
I believe the eGolf which was sold in the US shares the same drivetrain and battery.
Almost all non-Tesla EVs offer a heat pump option. Most non-Tesla EVs sold do not have one. Just go to your local VW dealer or whatever and see what the specs are on the ID.4's on the lot is.
You can easily read about your example VW MEB platform battery configurations, including built in thermal management system, online at the Munro teardown, for example.
Perhaps you are changing the topic from your original thermal management to heat pump systems specifically?
You don't even need a heat pump. You can just slightly overvolt the charger, so that some electrical energy is lost as heat rather get than transformed into chemical bonds.
> 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.
> You don't even need a heat pump. You can just slightly overvolt the charger
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.
Heat pumps struggle to do much at the temperature range the article proposes.
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.
Pretty sure the ones in most EVs today work fine at -10C, but they may lose some efficiency. The thing is, there's already mechanisms in some cars to generate waste heat specifically for this purpose. Tesla's already have the ability to run their motors 'inefficiently' generating waste heat, which can be pumped into the battery coolant and heat that. It's no better than electric strip heating, but it doesn't add any cost to the system.
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...
You bring up a great point. The battery spec is only given at -10C. That's a mild normal day's low temperature in winter in Minneapolis, USA. But it's often much colder than that for long periods of time. I wonder if this glassy layer they apply can handle -30C; a temp where above ground heat pumps are no better than electrical resistive heating.
The 5x delta is stated to be at 14F. That absolutely is within the reasonable operating range of a Model Y heat pump, not sure what you're citing?
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.
You can start gasoline cars just fine down to 20 or 30 below, so long as you keep a good battery in it. Sometimes big diesel trucks use block heaters but gasoline cars don't need them.
I live in a region where -40°C is not unheard of (it happens every winter and stays for up to several weeks). I've also been to another region (not far off) where -50°C is pretty typical.
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.
Stock gasoline cars do not do well at those temperatures. In Alaska most people with sense use engine block heaters, plugging in every cold night. Besides the issue of having trouble just starting the car, you will put excessive wear and tear on the engine doing it regularly.
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.
I can definitely say that old/USSR 2.7L gasoline engines for the military came with block heaters. But they were expected to start in -50C / -60F. Good luck getting anything out of an EV at those temperatures.
There's plenty of Norwegians on YouTube testing EVs down to those kinds of temperatures and they work absolutely fine, with the caveat that they won't charge until the battery warms up. Discharging Lithium batteries at really low temperatures isn't an issue, charging them is(because it actively damages them) - but even then the threshold is -32C or around that, easily overcome even with a simple resistive heater.
Link to the research article: https://www.cell.com/joule/abstract/S2542-4351(25)00062-5
How much more expensive will this solution be than putting a “block heater” into the battery to warm it up to room temperature faster while charging?
If the charge rate is reduced by battery temp and chemistry, shunt the surplus supply into changing the battery temp, no?
While the technology may be advantageous, it seems weird to write a whole article about it without mentioning the obvious solution: Just Heat The Battery. It's true that many early EVs (and most non-Teslas even today) don't ship with battery thermal management. But they won't be getting new battery chemistry either.
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.
> It's true that many early EVs (and most non-Teslas even today) don't ship with battery thermal management.
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?
My 2022 Volkswagen e-Up has zero thermal management of the battery, it's completely passively cooled with no heating. Not that it really matters, people have tested it and charging speed only starts to degrade after 3-4 rapid charges in one day, with "rapid" in quotes(in tops out at 40kW).
I believe the eGolf which was sold in the US shares the same drivetrain and battery.
Almost all non-Tesla EVs offer a heat pump option. Most non-Tesla EVs sold do not have one. Just go to your local VW dealer or whatever and see what the specs are on the ID.4's on the lot is.
You can easily read about your example VW MEB platform battery configurations, including built in thermal management system, online at the Munro teardown, for example.
Perhaps you are changing the topic from your original thermal management to heat pump systems specifically?
Those are different goal posts. There are other ways of heating a battery.
You don't even need a heat pump. You can just slightly overvolt the charger, so that some electrical energy is lost as heat rather get than transformed into chemical bonds.
> 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.
> You don't even need a heat pump. You can just slightly overvolt the charger
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.
[1]: https://youtu.be/JjPIuLz5VFI?t=1124
Heat pumps struggle to do much at the temperature range the article proposes.
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.
Pretty sure the ones in most EVs today work fine at -10C, but they may lose some efficiency. The thing is, there's already mechanisms in some cars to generate waste heat specifically for this purpose. Tesla's already have the ability to run their motors 'inefficiently' generating waste heat, which can be pumped into the battery coolant and heat that. It's no better than electric strip heating, but it doesn't add any cost to the system.
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...
You bring up a great point. The battery spec is only given at -10C. That's a mild normal day's low temperature in winter in Minneapolis, USA. But it's often much colder than that for long periods of time. I wonder if this glassy layer they apply can handle -30C; a temp where above ground heat pumps are no better than electrical resistive heating.
https://ashp.neep.org/ for a list of heat pumps that perform well in cold weather.
The 5x delta is stated to be at 14F. That absolutely is within the reasonable operating range of a Model Y heat pump, not sure what you're citing?
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.
You can start gasoline cars just fine down to 20 or 30 below, so long as you keep a good battery in it. Sometimes big diesel trucks use block heaters but gasoline cars don't need them.
I live in a region where -40°C is not unheard of (it happens every winter and stays for up to several weeks). I've also been to another region (not far off) where -50°C is pretty typical.
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.
They work down to -10. And colder than that too. Apologies to Mitch Hedberg.
Stock gasoline cars do not do well at those temperatures. In Alaska most people with sense use engine block heaters, plugging in every cold night. Besides the issue of having trouble just starting the car, you will put excessive wear and tear on the engine doing it regularly.
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.
I can definitely say that old/USSR 2.7L gasoline engines for the military came with block heaters. But they were expected to start in -50C / -60F. Good luck getting anything out of an EV at those temperatures.
There's plenty of Norwegians on YouTube testing EVs down to those kinds of temperatures and they work absolutely fine, with the caveat that they won't charge until the battery warms up. Discharging Lithium batteries at really low temperatures isn't an issue, charging them is(because it actively damages them) - but even then the threshold is -32C or around that, easily overcome even with a simple resistive heater.