Hyundai Kona Electric Thermal Management System Explained


Thermal management matters

Back in October, InsideEVs broke the news that Hyundai Kona Electrics destined for the US market would not have active battery heating. This came as a surprise to many, as the Kona Electrics already delivered in Europe had the ability to warm, as well as cool the battery as needed.

Even though we had confirmed this fact with Hyundai senior Manager of Eco and Performance Powertrains, Jerome Gregeois, there were some news outlets that questioned if this was correct since Hyundai hadn’t formally announced it yet. In fact, most Kona Electric articles and reviews continued to state that the vehicle will indeed have battery warming for the US market.

Hyundai Kona Electric “exploded” battery pack illustration

Now, our friends at Electric Revs have posted an extremely comprehensive article on the Kona’s thermal management system, and guess what, they confirm that US-destined Kona’s will NOT have the active battery warming feature found on Kona’s sent to most other regions throughout the world. They also seemed to confirm that Kona Electrics send to Canada will have the battery warming feature. That certainly makes sense, but it’s a fact we weren’t certain of after attending the Kona Electric Press drive in Los Angelos this October.

Additionally, the Kona Electrics sent to the US will not have the heat pump system either, instead relying on a less-efficient 5.5 kW resistive cabin heating system. Canadian customers will get the more efficient and more sophisticated heat pump system for cabin heating in addition to battery warming.

Despite the lack of a dedicated battery heater, the US version of the Kona does have the ability to scavenge heat from the electric motor and power electronics in addition to the heat dissipated by the battery itself to help keep the battery warm when operating in colder conditions. – Electric Revs

Interestingly though, the Kona Electrics that aren’t outfitted with the battery heating system do have the ability to use some of the excessive heat generated by the power electronics and electric motor to help warm the battery, but the extent of how much that will help is unknown.

The only reason we can come up with as to why Hyundai would do this, would be to save money so they could offer the Kona Electric at a more competitive price point. With the recent announcement of a $36,450 starting MSRP,  it appears they were indeed focused on bringing the effective price of the base Kona Electric under $30,000 after the Federal tax credit. Also, Hyundai has been very upfront with the fact that the Kona Electric will only be offered in the ten ZEV states. Additionally, they believe that the vast majority of vehicles will go to the California market where battery warming isn’t necessarily needed as much as it is in many of the Northern states.

For more technical details on the Kona Electric’s battery and thermal management system, head over to Electric Revs and read the full article.


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98 Comments on "Hyundai Kona Electric Thermal Management System Explained"

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Hyundai will only sell a limited number of Kona, and mostly in California. California doesn’t need active battery warming feature

Agree not needed in California, but how will that work for road trips, say, to go skiing?
Would fast charging in very cold temps require driving a bunch of miles first?

Yep, it surely would.

With very limited charging infrastructures even in California ski areas, I would not recommend to drive anything else than Tesla.
For local ski areas, cold temperature is not really a huge concern.

I wouldn’t jump to that conclusion. The Kona 64 kW uses less power than the Teslas, and has already beaten a Tesla X in a cold weather long-range test in Norway.

They have the Heater system in Norway…

Most people only focus on what they “like” and dismiss everything else. In fairness to Tesla, the Model X is a much larger, heavier car sporting two motors so we shouldn’t expect it to match Kona in mi/kW, but that “race” was an excellent showcase as to how good the Kona really is…and that’s driving around in a COLD country. The bottom line is that Kona, and soon Niro, and the new Leaf, and the Jag I-Pace, and others, will be bringing out cars for less money, with much better factory support and warranties, that will cause Tesla sales to tank for anything below the super-premium level. Maybe that’s why Tesla is already pushing their new Roadster which of course is ridiculously over-priced. WHEN the consumer market finally starts to fully embrace electric cars in the next 5 years, the “tuner” market will kick in. People will be shocked to discover how EASY electric cars are to tinker with, upgrade, improve, etc., and then all bets are off for the entire industry. Remember, electrons can be sourced from almost anywhere, but big industry has held us all hostage with gasoline for over a century, and that will do a lot… Read more »

Have you looked at PlugShare for fast chargers? Highway 50 and 80 between Sacramento and Lake Tahoe have the highest density of fast chargers of any rural highways in California. The Tesla Model 3 can’t even use them because the CHAdeMO adapter doesn’t work with the Model 3 yet.

Yes, I have looked at the CHAdeMO on Highway 80 and 50 and they suck. A lot of bad reviews and less than have the power of the Tesla Superchargers. Most DC fast charge is only 50 kW – not fast enough.

Sad face.

“Canadian customers will get the more efficient and more sophisticated heat pump system for cabin heating in addition to battery warming.”
How do we make the emoji for tongue out and jiggly antler ears 🙂
We don’t often get special treatment like this!

I wouldn’t call it “special treatment” since features like this don’t exactly come for free.

So price it out as an upgrade.

Strike Kona off the list, then.

It depends on where one lives.

Which is why it’s off my list.

Import from Canada Mr. B.

Will the warranty transfer to the states and can the US dealers get the any necessary parts to fix the vehicle.

As anyone who has ever explored importing a modern car built to foreign compliance regulations into the United States would know, that exercise is left to the seriously masochistic with money to burn.

I’m sure you will be able to add the “Cold Weather Package” option.

Good for Hyundai Canada … because that would be sure-fire disqualifier for my pre-order, especially after losing all rebates.

Based on the great reviews, I don’t think they’ll have any problem selling every one they offer for sale in the U.S. Hope Hyundai starts building EVs on a dedicated electric-only platform, and with AWD.

What about battery cooling? The hotter areas of CA and other states will be a bigger issue than the cold.

Hyundai did their homework regarding pack cooling in hot climates. Both the US and EU versions have a robust bottom-plate glycol-based battery cooling system with a glycol “chiller” connected to the AC system – similar to the Bolt’s – but the Kona’s bottom plate it has more cooling sub-loops that help it cool better. This is probably why the Kona can fast-charge at higher kW rates than the Bolt. Plus it can use the Kona’s main cooling radiator to cool the pack without the AC when the weather conditions are right, similar to the Tesla. This Kona EV appears to be a pretty amazing combination of great EV engineering + great price.

Bolt’s slow DCFC is not due to cooling. If that’s the case, one would expect faster charging in colder climate, but the step down points remain the same regardless of temperature.

It is insulated well enough that ambient temperature won’t matter much for charging assuming similar operational temperature after driving for a while. It needs to pull heat from the cells quickly enough and I imagine what is there doesn’t have a high enough heat transfer rate so heat would accumulate too quickly. It seems it would be an easy design update. It is also just pre programmed steps set on the safe side to maintain battery life.

If it’s thermal, starting charge at 53% after sitting in 50F (waiting for free chargers! arrrrggggghhhhh!!!) would not result in step down after only couple of minutes. It doesn’t matter what the temperature is, it ALWAYS steps down at 54% and 69%.

It will have battery cooling.

As per the linked article:

The three-way valves switch to Chiller Mode (labeled “Hot Condition” above) when the battery starts to get too warm. Hyundai hasn’t said what the exact parameters are. The coolant flows through a “chiller” which exchanges heat with the vehicle’s air conditioning refrigerant loop.

This is awful Hyundai, come on. People in the Northeast US experience severe cold weather. They need battery heater functionality just as much as Canada!

Let’s not forget that a resistive heater like the bolt isn’t going to cut it. My soul EV has the heat pump, and I’m sure Hyundai knows this

Tesla has no heat pump and people don’t seem to complain…

I’m not happy that my Model 3 doesn’t have a heat pump. My previous EV (Honda Fit) didn’t have one and having to turn on the cabin heat killed the range of that car. It does the same in the Model 3, but the bigger battery helps out. Still, it’s stupid to waste so much electricity (I’ve seen up to a 50% decrease in range in cold weather).

In the Bolt, I have never seen the winter “HVAC penalty” higher than 14%, and usually it’s around 10%. Whereas the winter range does go down 30% vs. the annual average … so most losses have to occur elsewhere.

I have a Bolt now; used to have an early LEAF with the PTC resistance heat. The LEAF kind of felt like a rolling refrigerator in Ohio winters – took a long time to warm up. The Bolt heater is much better, warms up fast- you can really see the heater apparently take a bite out of range initially if the Bolt has been parked where it can not be set to precondition the cabin. Once the Bolt interior is warm, the heater seems to back off energy consumption a lot, however cold driving range is still less. Winter range seems to be reduced by more than the percentage of energy being used for HVAC. I wish the Bolt had a better graph to show in real time how much energy is being used by the various subsystems as the LEAF did. Having a large battery helps mitigate the impact of resistance heat, but it still bugs me to burn so many electrons for cabin heat without getting the multiplier effect of a heat pump. The electonic nanny in the LEAF really drove me nuts. Any touch of the heater controls would force outside air intake and compressor on. The… Read more »

Bolt EV has a more powerful resistance heater (like 7.5 kW, this is only 5.5 kW) as well, this is on the weak side for cold climate, probably need to preheat cabin both ends of the trip. Similar to i3 REx, which I am nervous to see how well it works at -25 C as it also has a small 5.5 kW or so heater.

I think the Bolt has larger interior volume for the heater to cope with … but generally speaking, given that an electric powertrain generates a lot of waste heat than an ICE – all EV’s should have heated seats as standard.

More proof they really only plan to sell to California buyers.

Not just the Northeast, either. Here in Kansas it gets bitterly cold for at least several days during every winter.

“Despite the lack of a dedicated battery heater, the US version of the Kona does have the ability to scavenge heat from the electric motor and power electronics in addition to the heat dissipated by the battery itself to help keep the battery warm when operating in colder conditions.

This thermal management strategy is somewhat similar to that used by Tesla, and the startup automaker Rivian among others.”

Why are people complaining?

By itself, it’s insufficient in conditions that are cold enough to start freezing the battery electrolyte. Even when it’s not frozen, there’s significant degradation in the ability to extract power from a very cold battery.

Bjorn’s winter test showed only 25% loss without the battery heater coming on. Bjorn was able to get 44kW charging speed on 50kW charger. For 90% of the country, battery heater is not needed.

Bjorn tested the Kona in July. The 44kW charging rate was achieved at 28 degrees Celsius, which is roughly 82 degrees Fahrenheit. Did you mean the Kia e-Niro? Bjorn managed 44kW with a warm battery (car in heated showroom), but later, with battery cold soaked the e-Niro charging was disappointing at the 175kW charger.

Only the Tesla Model S and Model X seem to have good all around cold weather capability. The Tesla Model 3, Jaguar I-Pace, Hyundai Kona, Kia e-Niro/Niro EV, and Chevrolet Bolt all seem to have design compromises that limit their cold weather capabilities in one way or another.

Kona, soul, and niro are same ev with different styling. Bjorn, on live stream, is getting 46kW on a 50kW charger.

No ev , s and x included, can charge fast when battery is cold soaked.

Do you even own an BEV?

We’re only speculating about the new soul EV, so until we have this info, we can’t assume it’ll be the same as the Kona

“This thermal management strategy is somewhat similar to that used by Tesla, and the startup automaker Rivian among others.”

As I understand it, the Tesla Model 3 (which doesn’t have a resistive battery heater) is engineered with a motor mode which actively generates heat; a mode which is deliberately inefficient so it will generate heat, when needed. (Hopefully it’s clear that mode is only used when battery heating is needed.) So that’s how Tesla is able to get away with no battery heater in the Model 3.

Unless Hyundai is doing something similar with the Kona, then this isn’t actually a similar case.

I don’t know what Rivian is doing with its vehicles, so won’t comment.

Does lack of a dedicated battery heater in cold climates only affect the rapid charging capability, or are other aspects of the battery performance impacted?

Only rapid charging. The battery heater only comes on when the weather is below -10°C or 14°F. The kona should get 44kW on 50kW charger.

I can’t speak to the temperature at which the battery heater on a Kona will come on. However, your other two statements are inaccurate and/or misleading.

May also reduce usable capacity.

Yes, 25% reduction which is really good for a EV in winter.

The Bolt, on the other hand, has terrible range in winter. You can expect 45-50% range reduction in the Bolt EV. DCFC becomes useless when the battery is cold soaked. Make sure you charge first before letting your bolt sit in the cold.

Nobody on the forums is reporting less than about 150 miles in the coldest conditions.

My winter range with hilltop reserve activated is about 130miles. My 3000 mile aberage is 3 m/kWh. My worst day so far was 2.4 m/kWh over 65 miles. The Bolt is an around town car only during the winter.

To be more precise, it reduces the full capacity, which may reduce usable capacity. Not that I think that nit-picking clarification means Bro1999’s comment deserves a down-vote.

To be more precise: lower temps reduce the pack voltage and thus the amount of energy (= I * V) it can provide.

Regen is limited, at very cold temps, the battery can be damaged, ability to hold a charge is dminished slightly but the most important is slower charging.
There are warnings not to store EVs in super low temps for a long time. At least if plugged in, a heater can eliminate that risk.
Supercharging has been as low as 5 kw when the battery is really cold. So rapid charging can really be diminished.

Cold batteries are limited in the amount of power they can provide, and in the amount of power they can accept. For example, Google “Tesla Model 3 Snowflake” to see how cold weather affects that car.
The battery cells need to be in their temperature comfort zone to function safely and effectively. To prevent damage to the cells the Battery Management System (BMS) will limit the amount of energy entering and exiting the cells based on, among other things, temperature.

Another compliance car ,( eastern USA does not get battery warming & heat pump)

another compliance car?

“Hyundai has been very upfront with the fact that the Kona Electric will only be offered in the ten ZEV states.”

The world is slightly larger than 50 ZEV or not ZEV states.

Like I said before, the Kona EV is a compliance car special.
Also: “Thermal management matters”
Not to Nissan. Lol

Wanna bet it will be sold in more placed than the Bolt?

More outside the US. Less inside the US.

For US sales? For sure I’ll bet.

I find myself in rare agreement with Bro1999. Don’t understand the down-votes here; he is 100% correct.

I agree. The US spec Kona is sadly “dumbed down” relative to the rest of the world, and will only be available for sale in ZEV states. The largest percentage of sales will likely be in California. Thus the US spec Kona could be considered more of a compliance car than the Chevrolet Bolt. Not that I’m fond of applying that term to two very capable BEVs with an excess of 200 miles of summer range, but both saddled with a few disappointing design and marketing decisions that limit their potential.

What many fail to realize it’s the sheer size of the US that dictates the regional differences in BMS and heating. Kona sold in warm countries will probably not have battery heating. The southern us is vastly different than the North, but clearly the northern US should get Kona same as Canada

Happy you were able to finally clear this up, Tom. Pricing is CAN $51,999 for the top trim.

If true that is a good deal. Equal to about $39k US and for the loaded model no less with the heat pump/battery heater. I wonder how Kia will equip the niro electric. I hate the idea of resistance heating (except for seat heaters and the like); It seems so foolish.

The news about the lack of battery heating is disappointing. My kia soul EV does have battery heating, but those models not sold on northern states didn’t have it. My lease is up in 2020, and I would be seriously considering either the Kona or soul EV, but since I’m in NY, I’ll have to reconsider. Hopefully this news is premature, since they’ll be sending units with thermal heating to Canada, why not northern states as well

Well, if you are only planning to deliver to sunny California, why include cold weather options.

Waiting for an under $40k EV with AWD. Too bad the Kona or Niro are not offering it.

Anyone know when the release date is? Last I heard was “December 2018” in California, followed by “a couple weeks later” for the ZEV states.

Hmm, BMW i3 has battery heater below 50F. But a smaller battery.

The competition just does not seem to want to put anything out there similar to a Tesla…..always cutting corners or charging a huge premium….

Model 3 has no battery heater, right?

Model 3 uses the motor in an inefficient manner to deliberately generate waste heat for battery warming. Apparently it’s either not as strong as the resistance heaters in Model S and X, or not available when the car is moving, or isn’t activated until lower temperatures are reached, or some other limiting factor. Details are as of yet unclear, but it doesn’t appear as effective. Also, I’m not sure if the Model 3 battery is insulated like the Model S and X batteries are. It may lose heat more rapidly. Hopefully another over the air update will help address the issue.

So the good price in the US has an explanation. Heating Kona with the US version will be like 3 or 4 times less efficient.
Fancy battery managemen it’s great but it seems costs are important.

Proving once again that GM is the worst non-luxury EV automaker… except for everyone else.

Good grief. If they are making it it standard equipment in the Canadian version, they could at least make it an option for the U.S. version.

This is the kind of thing an auto maker does to a BEV if it plans on treating it as nothing more than a compliance car. 🙁

One more thing to go wrong, my LEAF needs no such system.

Mine sure did. Was happy to be rid of that thing.

So what happens when they enter the used market? Those buyers, possibly from other states like eastern OR or NV where it is much colder, may not know the difference.

Hyundai wants Californians to buy this car in volumes in order to get a point when Hyundai can bear the expenses of a better temperature management systems and sold across all regions of US at a marketable price. By then the cost of battery will be lower.

I think Hyundai and Kia did it to keep price under $40K to qualify for state rebates in CA and OR. For skiing, destination charging is going to be the key, Tesla, Hyundai and Kia’s will mostly be super slow charging on available 15A circuits plugs in rentals apts and condos but that’s OK. I rarely use the car once I get there so a couple days to fully charge on any them isn’t a show stopper.

Canada is doing being push on “Electric Highway” and hopefully will have enough CSS Fast DC chargers to make the run to Whistler doable with one DC fast charge.

Oh yeah, another quota car.

I’m starting to get on the Tesla bandwagon, the mere fact that other mfgs are dodging full TMS’s illustrates how non-committed they are to full EV Adoption. Add in the charging network that Tesla already has in place……it’s starting to feel like everyone else is too far behind. My wife, brother and I have had six Nissan Leaf leases (2013’s and 2016’s) and the batteries on those/these cars suck. I work in Fremont and see the thousands of Teslas rolling around and sitting on trucks heading out for delivery with full TMS and you begin to realize that they are nearly at critical mass. Perhaps the Germans are coming for them, but they better hurry and they better get some chargers in place, otherwise mass adoption ain’t gonna happen.

Only difference seems to be slower DC Fast Charging in colder weather and that only if the car is not driven prior to getting to the charger as driving warms the battery. As the article notes, range/output of the battery is not affected by the lack of a battery heater. Niro and Kona are really the first practical (hatchback, ground clearance), full featured (all the gizmodos including heads up display) and price competitive EVs and with the $7500 and $2500 (under $40K to qualify for OR state rebate) tax credits. These will sell out fast. Only issue on travel is that they use the CSS fast charging vs. the Chademo and a lot of the current chargers at WalMarts and Freds in our area have the older Chademo fast charge. For apartment dwellers, being able to fast charge while shopping will be an issue unless Kia and Hyundai make a CSS/Chademo adaptor. A lot more features than the Model 3 (hatchback, heads up, ground clearance, blind side indicators, FWD) but Tesla does have the fast charger system for those who can’t do home charging. Be interesting to see where the AWD, 250M range Model 3 is priced as it won’t… Read more »

Let me see: No dedicated battery warming for US models, no heat pump for US models, AND only available in ZEV states. Sorry Hyundai, you’ve lost two potential sales to my family with these decisions.

I’m more interested in battery cooling personally. Living here in Phoenix for the four months out of the year that are hell on earth, I don’t know that I would trust a battery that doesn’t have a cooling system.

US spec Hyundai Kona – yet another Compliance car…

But seriously, how much could a 4-way reversing valve to implement HVAV and battery heaters cost? If the Kona is effectively being relegated to a role of compliance car in the US, does it really matter if it costs $1K more to outfit properly? Konas are going to be driven by early adopters, and my assertion is that good will word-of-mouth advertising generated by being a superior car is more valuable than appearing to try to price-match the Nissan LEAF.

Maybe the battey heater isn’t so important in California, but leveraging the nearly 4:1 cool weather efficiency gain of having heat pump HVAC will definitely be noticed by drivers in California – maybe more noticed in California than Canada because it may be too cold for the heat pump in mid winter Canada.

Recent articles read as if the Kona is going to be even more vaporware outside of the compliance states than the Chevy Bolt.

Kona looks competitive. 250 mile range. FWD and 7″ ground clearance for snow sports, CSS fast charging, hatchback, heads up, aggressive design, Apple/Google, all the options and should come in around $45 maxed out but get full $7,500 tax credit.

The heating system doesn’t cost range per article, just high speed charging rate when cold so not much real world penalty for the cooling only system.

Should be a great working man’s EV.

That is really idiotic – beancounting decisions rather than consumer/intelligence/safety/reliability/usefulness decisions!

Seems to me it would be more expensive to develop and manufacture such a significantly different vehicle!! Wouldn’t it be cheaper overall to just make one battery system???