Charging electric vehicles 5x faster in subfreezing temps
119 comments
·April 5, 2025Animats
cuu508
> Things that have a small solar panel, a battery, and no grid connection could benefit from this.
As a side topic, what are the currently available options for this?
I've heard about sodium ion (safer but still not sub-zero charging friendly, also no easily available solar charging controller boards), lithium titanate (same), and plain old deep-cycle lead acid.
For small solar-powered projects, it would be nice if there was a power bank on market which supported solar charging, and could either be safely charged in freezing temperatures, or had built-in temperature sensor and reject charging when it's too cold.
hgomersall
According to this sodium ion battery product, it still charge quite happily at -20 degrees C:
https://midsummerwholesale.co.uk/buy/eleven-energy/4-5-kwh-s...
nicolaslem
Most consumer LiFePO4 power stations have this sensor and cut charging below 0C, still allowing discharge up to around -10C.
LinuxBender
For completeness sake there are also many LifePo4 battery options that have heating pads that will activate below a certain temperature. Even Amazon have about a dozen brands with heating pads.
malchow
Not for cars yet, but Enovix has short-ion-path batteries intrinsic to its lithrographed 3D design. Performance is quite something: https://www.enovix.com/products/
throwaway41029
The big news on EV charging is from BYD in late March when they announced (and it caused TSLA to fall by a few percent) that their new line of superchargers will be able to charge cars to give them a range of 400 km in just a few minutes. This is the state of the art in production
https://www.ttnews.com/articles/byd-5-minute-charging-rivals
timerol
The state of the art (not just for BYD) is to make sure you don't have to charge a cold battery by getting it to the right temperature before charging. One of the reasons that Tesla (and others) has navigation integrated into trip planning integrated into the vehicle is so that the battery temperature can be optimized in the 10 minutes before you start charging, to maximize charging speed.
BYD would not pump 400 kW into a battery at -10 C. This research helps in the situation where you have a cold battery, and need to start charging it before it can warm up.
bufferoverflow
That requires 1 megawatt chargers. For each charger.
Not saying it's impossible, but that won't be easy.
michaelt
The US consumes 376 million gallons of gas per day. Which is equivalent to a continuous power draw of 500 gigawatts.
Megawatt chargers? We'll need the generation capacity to support 500,000 of them.
bufferoverflow
What does whole country consumption have to do with building megawatt chargers?
The problem isn't trivial. If you have, say, 10 charging spots on a lot, each requiring a megawatt, how are you going to deliver that? Are you going to build a whole substation for every charging parking lot?
indemnity
I mean, this is great, but BYD has pretty much zero installed charger footprint in markets where the Supercharger network exists.
Is that going to change?
bgnn
They are expanding in Europe rapidly, and in China of course.
In the Netherlands they are partnered with a local green electricity provider (Vattenfall) and Shel for their charger network. Shell owns the most petrol stations along the highways, so they will have their chargers there for sure.
I'm expecting the tariffs on Chinese EVs to be rolled back in EU after the US tariffs. They might want BYD to open local factories, like NIO is planning to do.
3D30497420
> I'm expecting the tariffs on Chinese EVs to be rolled back in EU after the US tariffs.
I doubt it. This would likely have a significant negative impact on domestic EU car companies, most of which are considered cornerstones of their local country's economy. Now, whether this should happen (to benefit consumers/the environment) is another argument.
ffsm8
Considering current politics: not in the US, at least not for the foreseeable future.
Europe remains to be seen, but also unlikely short term as we're also slapping lots of tariffs on chinese EVs to protect local industries
LoganDark
Countries really need to stop unfairly penalizing Chinese EVs. If they aren't allowed to compete, local industries will never have an incentive to improve. No argument about safety has ever had any merit - Teslas burst into flames all the time.
Peanuts99
Isn't their plan to sell them to charger operators?
notahacker
Yeah, would have thought if BYD played it smartly and the tech is that far ahead, they could get a lot of market share from batteries and chargers even if Europe's car brands remain strong and protected.
hinkley
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?
edaemon
The battery can be large enough that it takes a long time to heat it, but that's usually what an EV is doing when it preconditions the battery for charging. My car (and pretty much all EVs) will precondition the battery if the next navigation stop is a charging station, for example.
xattt
This assumes that nav data is current or a telematics subscription is active. As Alec Watson of Tech Connections fame recently pointed out about his first-gen IONIQ 5, this needs to be feature accessible to the driver.
ssl-3
Even then, it still assumes that users understand that it is a problem in the first place and that they are willing to take steps to solve it.
For most people, a car is at least the second-most expensive thing they'll ever own -- as well as the most expensive machine they'll ever own. It is also something that many are very unwilling to RTFM for, often to the point of irately defending this unwillingness and the resultant ignorance.
An improved battery that can charge quickly when cold (while maintaining safety and longevity) solves many problems, including some that may be self-inflicted.
tirant
Indeed. For example in most cars, if you decide to use the navigation from Apple's CarPlay or Google's, the vehicle will not pre-heat the battery before charging.
In my BMW EV we recently got an update and it's now possible to manually pre-heat the battery, not only from within the car, but also even remotely via app. You can even lookup now the battery temperature.
officeplant
Yep, I refuse to pay for Ford's navigation. As of now neither carplay, nor android auto, can turn on battery preconditioning in my van. I've been monitoring the battery heater state in an app just in case it starts working in a future update. Recently an update finally allowed carplay to read my E-Transit's SOC when connected.
It would be nice if I could figure out some way to just force it on with a switch/aftermarket module talking to the canbus.
jillesvangurp
This pre-conditioning isn't free. It costs you range. So, doing less of that helps. And it takes time. The worst case for an EV is a short journey to a fast charger. Both heating the vehicle and the battery from ice cold takes energy.
hinkley
Which the charging station has in spades. You should be able to run the heat pump at full bore when attached to a charger. And a regular heating element. Modern heat pumps have both, why not cars?
homeless_engi
Many EVs (Teslas) already contain a heat pump to warm the battery. I presume that improved battery chemistry would supplement this -- but maybe replacement would be possible?
gmac
Not only Teslas: my Renault has this as standard, and many brands have it at least as an option.
eatporktoo
Tesla already heats the battery in this way- it essentially just puts opposing fields into the motor to generate excess heat even when not moving.
https://electrek.co/2017/08/24/tesla-model-3-exclusive-batte...
ethagknight
Not a battery expert but part of the challenge is too much heat in some places, not enough in others, so heat management is a big challenge, but coolant routing is complicated. The heat pump is a big deal and far more efficient (4x?) than a 'block heater', and resistance heat is the old solution that the industry moved away from.
I believe the "microscale channels" are a better solution that reduces the amount of heat generated at the connection points of the battery, and also reduces the high temperature gradient at high voltage charging at low internal temps (high internal temperature delta), which I understand to be a primary cause of battery degradation.
Rebelgecko
At least in my car, fully preconditioning the battery can take an hour or two when it's really cold. If you're still on the way to the charging station, it can also impact your range. My car is annoyingly conservative about when it uses and disabled the preconditioning
ellisv
Link to the research article: https://www.cell.com/joule/abstract/S2542-4351(25)00062-5
ajross
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.
jbm
In winter, I lose 5-10% of my battery a day due to heating my battery. Tesla is nice enough to hide this under "You should keep your car plugged in all the time" messages. It's really a pain, especially if you have a relatively small battery to begin with. I have a 2019 Model 3 w/ a 50 kwh battery, and use 10-20 kwh on a regular basis; 5 kwh wasted means as much as 1/3 of my energy use is effectively waste.
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.
sbierwagen
When I bought a Model 3 last year I knew full well the issues with charging, temperature capacity loss, battery heating, etc. What I was surprised by was loss of regen! If the battery is below 20F or so then the firmware will only give it a trickle of regen braking. After all, it's effectively very fast charging, which a frozen battery can't handle.
I wonder if regen braking going to zero is behind some of the horror stories of sudden unexpected range loss in cold temps.
ajross
> In winter, I lose 5-10% of my battery a day due to heating my battery.
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.
gopalv
> what it actually means is that this magic battery doodad needs to provide 90-95% of the performance of its existing, mature competitor
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.
jjtheblunt
> 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?
gambiting
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.
formerly_proven
Different drivetrain and battery for the eGolf, but both of these are effectively 2013 EVs.
ajross
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.
jjtheblunt
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?
recursive
Those are different goal posts. There are other ways of heating a battery.
linsomniac
Heating, in its various forms, has one big drawback that having a battery that can charge faster in low temps would be really nice in: Starting the day needing to charge.
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.
bdcravens
> (and most non-Teslas even today) don't ship with battery thermal management
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)
cyberax
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.
lazide
That doesn’t work when the problem is the battery is already sub-zero - lithium plating occurs when trying to charge in those conditions, destroying the battery.
You can’t just overvolt out of that - you need an external source of heat until you’re out of the dangerous thermal area.
formerly_proven
I'm not sure if that affects all chemistries and compositions. If you look at the spec-sheet for e.g. the LG E63 cells used in some older EVs (notably without TMS), those specify charging down to -20 °C - and the owner's manuals certainly have no warnings in them that the car will implode if you charge in the winter.
magicalhippo
> 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.
OptionOfT
Heat pumps also serve for more efficient heating when you're driving. Just like at home where a heat pump is more efficient than a resistant heater.
jve
I mean this is an incremental improvement that would be very welcome. Why be so negative? Look around the products that have lived through decades of incremental improvements and compare them. Like the phone in your pocket or computer you are using.
givinguflac
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.
Kirby64
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...
superkuh
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.
ajross
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.
idiotsecant
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.
Rygian
https://ashp.neep.org/ for a list of heat pumps that perform well in cold weather.
null
wolfi1
it seems a little bit dubious to me. You can't beat the Arrhenius Law, not in Electrochemistry, anyhow. The ion mobility would be very very low, you'd have to rely that the temperature in the battery itself is above 0°C
null
saurabhshahh
can we do it for the smartphones first? without turning them into a furnace
awiesenhofer
How often are you charging your phone in sub-freezing temperatures?
bufferoverflow
We already have smartphones charging at 240W: Realme GT3 and Realme GT5.
9.5 minutes from 0 to 100%.
RKFADU_UOFCCLEL
Nice to see that they require minimal changes at the battery manufacturer. Too often people come up with good ideas like this without accounting for other factors in the supply chain.
byyoung3
now they just have to figure out how to make it charge while people are lighting them on fire
curtisszmania
[dead]
Company web site.[1]
The real claim is 10 minute charging of lithium-ion batteries with a process which is a minor mod to existing battery production.
There's no product yet.
Batteries with good low temp behavior have many specialized uses. Things that have a small solar panel, a battery, and no grid connection could benefit from this. Even flashlights could use this.
[1] http://arborbatteries.us/