Tech Talk - Why do electric cars have radiators?
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- เผยแพร่เมื่อ 7 ก.พ. 2025
- In this episode we look at thermal management and discover why electric cars have radiators. We compare the efficiency of an old V8 engine to a modern Tesla motor to find out why you need to manage the heat from both and the technologies used. As well as cooling we also have a look at how to heat battery packs up if they are too cold.
4:21 , spud in the background 😁 ears perked up . "who's putting the kettle on , will there be biscuits ?"
I always thought about designing a fan that would run on the actual pressure on the radiator instead of using electricity. That way it would run faster if there was more heat. Basically the change in water pressure would push a piston out that is connected through a non-centred pin in the fan blade, a lot like how stream engine works. When the revolution ends, the water would be pushed back to circulation through release valve.
You could only use the water pressure to run the fan if the pressure was passing from a pressured, to non-pressurised location. Regrettably that would be non-returnable…
@@philtucker1224 The steam would need to be cooled down and compressed back to liquid form, but that isn't a big issue as it's already routed near fan blades. Obviously it would take more space than electric fan.
Around 9:30 - The permanent magnets in the motor also need to be kept cool. If they are Neodymium-based, the will start to lose their magnetism at much lower temperatures than Iron-based magnets. Their Curie point can be at temperatures below the boiling point of water, depending upon the grade of the magnets. Once the Curie temperature has been reached, all magnetism is lost, permanently.
Another tour de force from you Richard, very clearly explaining a very complex subject with the aid of the actual components of EV systems you use 👍🏴😎
I think we need another video of the Transporter Syncro.
Cheers
Thermal management master class. Awesome quality content. 🎉
Very interesting on battery temperature thanks for the video
Fantastic video really enjoyed it
Worth pointing out that internal combustion engines are only up to 30% efficient when fully up to temperature, they're much worse while warming up. And since most people take short trips
Not forgetting the time wasted at Pedestrian Crossings, Traffic Lights and congestion of our roads. Engine warm-up time in Winter. We must take this into account, simply because the engine is running, wasting fuel. Unless you drive a Blue Motion Car, your efficiency drops like a stone! In a situation like this, EV's conserve energy. Most drivers do not drive long distances, so the EV would suit the majority. It's always the high initial cost that prevents a greater uptake of EV ownership. It's great to have both an EV and also ICE.
Which is why I have a trickle charger connected to the same plug as my block heater. The amount of electricity required to start an engine below -20C needs about 10 minutes at highway speeds after the car is warmed up, which takes about 10 minutes of idling and 10 minutes of driving. So thirty minutes of burning fuel for my short city hops on cold days. Or a trickle charger. Then there's the engine repair bills for driving an ICE vehicle in Canadian winters.
You're a great teacher Moggy
Wow. Big block Mopar lump in that Jensen. I know it's horribly inefficient but what a beast.
Great vid, learnt a lot, thanks!
''Spud'' on presentation as always. Thank you for sharing the info, I just wait to see how Buffy comes to life.
I have a 1973 Super Beetle, so I'm used to little to no cabin heat. :)
I have a 1971 Beetle - also with little Cabin Heat. I just suck extra-hot mints when driving.
Great video mate 👌
diverter valves and the whole AC system + chillers also make the tesla thermal system awesome 🤟
Really great video 👍
Thanks 😁👍
I guess the only question remaining for me was why did the early Tesla's and some modern electric cars push so hard to have no front grill or as large a frunk as they could make? I know the heating cooling system does not need to be as large, but was it just a marketing thing, something to set them apart? The old gas powered radiators were positioned where they were because that would get the most air flow in motion, it makes sense to keep using the most efficient location for your radiator and heater system.
I think it was purely because they didn't need as much air flow so it gave the designers more of a free hand to design the front without the need to have a big hole for the radiator but rather go with sculpted vents for the air intakes. 👍
Aerodynamics. With an ICE you want as high a volume of air as possible bumping into the radiator to cool the engine. With an EV you need far less air ad thus you can improve efficiency by having smaller air intakes.
From a technical standpoint I found this episode to be the most interesting so far! Coming from a mainframe cooling background it was always our target to run the cabinets at 27degrees C. At what temperature (ideally) is a typical EV coolant system thermostat set to operate at please?
It depends if it's the battery coolant system or the motor or inverter as they all trigger at different temperatures. Also, they bring in the pump speed and fans variably rather than on or off like a thermostat.
I am always interested in tech talks of all sorts. This is probably why I am interested in new tech that is just becoming available that will effect the EC market. I was wondering if you have plans to cover any of that kind of tech in a talk in the future? There are two things that really stood out for me:
1. Super or Ultra Capacitors. I know that these are being used in a sort of hybrid fashion for some diesel powered fleet vehicles. I know that they can charge extremely quickly, but that they have a limited time for carrying the charge. I was wondering if there is any real effort to combine these with normal lithium batteries in a hybrid fashion.
2. Magnetic Resonance Charging. In particular, WiTricity. This looks like a very smart way to go with charging ECs in the future, and has lots of potential.
But what I really wonder about, is combining the two. If you had Magnetic Resonance pads placed in the road every 50 feet or so, and Ultra Capacitors picking up the charge as the car passed over them. Would it work? Would it be financially feasible? Kind of like old time electric street cars, but with the power in the road below instead of a wire above. Your car would just go, and never need charging unless you leave the main roads, then you would have a much smaller battery to get you that supposedly short distance to your destination. And Capacitors can be pretty much any shape. They can be in the frame of the car! Am I on to something, or is this whole idea a non viable pipe dream? 🤔
Supercaps are starting to be used on some high end performance EVs as they store that quick spike in energy from regen/braking very well. Batteries on the other hand don't like big spikes in incoming amps. I've also seen them used on Hydrogen fuel cell cars like the Riversimple Rasa.
Inductive charging is an interesting concept and I've seen it used in China for taxi ranks but the installation in the road is troublesome and the long term maintenance of them embedded in the road is yet to be seen. You also need to carry more weight in the components on the car to charge off the system. Lastly, it very slow charging speeds too. So I think it's a case of, yes it can be done but I doubt it'll ever become widespread. 👍
@@ElectricClassicCars Thanks for the quick reply. Sort of what I thought. It seems like a thing that could be done, but as long as nobody can profit from it...
Hmmm.. Didn't this happen to some famous guy? What was his name again? Oh yeah I remember, Tesla. Wanted to give the entire world free energy. Whatever happened to him?
(I'm being satirical, don't answer, I am well aware of his fate.)
Brilliant explanation as always.
@@spudproductions7606 my pleasure, so now we are friends will you convert my Nissan Navara 😂
thank you
I‘ve seen a video from teslabjoern, where he said, that tesla is using the motors to heat the battery. The car was stationary and the motors were pulling amps. Can you explain how this works?
Joule heating in the stators while not rotating their magnetic field
There's a video from a guy in Colorado which shows this happening when he tested recharging his battery after running it down to nothing and letting everything cool to outside temps of -20F / -30C. The Tesla fast charger has to heat the battery before charging, which took about 20 minutes.
When will you be fitting model 3 motors in your conversions?
The 3.54 reduction gear option looks good for a Land-rover to keep the cruising RPM down and in that super-efficient power band, even if it looses a little on the drag strip!
We've been fitting Model 3 motors in some builds for over a year now. 👍
@@ElectricClassicCars Have any been TH-camd yet? I must have missed them. I've seen you do Large Drive Units and Small Drive Units and some non-tesla motors (Hyper9 I think?)
I would have thought they would have used a water less coolant for corrosion resistance considering the cooling plates are aluminium with smaller waterways than a combustion engine.
Yep, we do. Usually G-48. 👍
Excellent!
Excellent 👌🏻
The cooling plates between the pouch batteries doesn't look very efficient as it's only a milled round channel.
Micro fins on the internal surface would increase the surface area and drop the temperature quite a few degrees.
Those plates were only an example, they weren't actually the true coolant tracks as those coolant plates are sealed and can't be opened to show. But ,yes you are correct they 100% be made to be more efficient. 👍
Really interesting thanks. If Teslas have these multiple radiators, why no grille to increase cooling efficiency? Aerodynamics more important?
Kia make heat pumps an optional extra on the excellent EV6's. Some models/countries as standard.
All you need is to do is add a reversing valve to your AC compressor and you have a heat pump! These should be standard - not a massive additional cost depending on if they think they can get away with it in a certain market.
@@TC-V8 The Heat Pump is on a separate cooling/heating circuit to that of the AC. Not the same thing.
heat is good when driving in below freezing -20c.
Do you need cooling for a smaller motor and inverter for something like a Fiat 500?
Yes.
@@ElectricClassicCars Could you do a video on the pros and cons of cooling vs not cooling? Also, what specific items need to be cooled and in what order of importance, battery, motor, inverter, controller, converter, not sure what else might need cooling.
I know of an electric VW with no cooling but the owner said he was going to install a pump and radiator system to cool the battery. Thanks for your shared experience!
Well done.
I dig the cameo at 6 minutes.
One of my pet peeves is why 'heat pumps' aren't used more in EV's.
ALL EV's already have an electric ac compressor. All you need is to add a simple reversing valve and you turn your AC into a heat pump. Simple and cheap.
Resistive heaters when you have limited energy are crazy in my humble.
You're right, and that's why most EVs are now starting to use heat pumps. 👍
Resistive heaters are 100% efficient. Heat pumps don't work well in the winter and the systems are very expensive.
@@vidznstuff1 100% efficient at turning electricity into heat _but_ a heat pump uses less energy to move more heat around so it takes less energy to move a given amount of heat around with a heat pump that to "create" that heat with a resistive heater.
If you're smart with your system design you can take heat from the battery/drivetrain to heat the cabin when it's more efficient to do that then take it from the outside air.
There's a limit of course but there are definite gains to be had using a heat pump.
@@Surestick88 And so, my home heat pump is ~300% efficient, i.e. with the same amount of electricity it MOVES 3 times as much heat into the house as the same amount of electricity CREATES in a simple heater.
@@vidznstuff1 You already have 90% of the parts for a heat pump - the compressor is no different to your AC compressor - ALL you need is a simple reversing valve which switches the refrigerant flow.
Yes they are less efficient when it's freezing than when cold, but still much more efficient than a resistance heater which can only ever be 100%. Heat pumps can be 200% - 500% efficient!
It makes them cool
Richard, in your conversioins, on the cooling systems, do you use common auto anti-freeze or glycol or maybe Dex-Cool? Thanks, these vids on details are great.
We use either G-48 or HTF-LS coolant. 👍
@@ElectricClassicCars Thanks.
MKlll Interceptor was 7212cc
What's the thinking, behind having a separate 12v battery?
Is it more efficient, to lug about an extra battery, than the weight of a converter to supply the current for high demand heater etc? (Or ICE ,although not seen any of your builds, with decent 'pimp my ride' stereo systems in....🙄)
There's still a 12v system on all converted and new electric cars for things like lights and wipers. The 12v battery doesn't need to be big as it doesn't need to crank over an engine. Some manufacturers (including us) have started using Lithium 12v batteries which are insanely light. You need a permanent 12v to be able to switch the car on. 👍
@@ElectricClassicCars , so more of a safety feature? As the full battery isn't 'live' all of the time. Kind of makes sense, cheers.
On the subject of batteries, what's the C rating on these things?
Had a wee look, but can only really find charging C ratings - pretty similar at every other battery chemistry, charging at 1C for battery longevity, but lithium having ability to charge a 3C? (While liHv are knocking on 5C?, or is 3C with a safety margin?) , but can't find much on the 'Burst' or 'Contiuous' discharge rating.
Me on my watercooled, 240x120xmm radiator PC drawing 50 watts: Yeah, that's a good question. A radiator for an electric car?😝
Can you use the existing radiator in the car for all the cooling ??????
Usually you can. 👍
Will there be another series of Vintage Voltage made please? If so, when will it be shown? Thanks!
A simple notion that struck me when I saw a documentary about the making of the Bugatti Veyron: just testing the isolated engine, it ended up literally melting the venting chimneys of the facility "the fact is that this engine doesn't produce 1000 HP but 3000: 2/3 go wasted in heat". Whatever the power supply of the future will be, automotive cannot prescind from the electric motor
If the coolant system is open to atmosphere surely it will evaporate.
Thank you, this helps me alot with my build! Question: Have you done a build/calculation/verification of a EV conv were you do not have liquid cooling/heating on the batterypacks? Lets say a pack with high voltage but you limit the power of the motor? Or a cruiser with small motor but a big pack for range. What is your experience and thoughs? :)
If you limit the amps going out and coming into a battery pack you can probably get away without cooling if you're in a temperate climate but it won't do you pack any favours in really cold weather. Whatever you do, make sure your BMS monitors cell temperatures and acts appropriately if they get too hot.
@@ElectricClassicCars Thank you, well it does make sense with your talk in the video about degradation now a days are so low thanks to watercooled/heated packs with good temp control. Only that argument itself is strong enough to push 100% temp control in every EV conversions. Na, I live in Sweden so as you say, there is really no option without thermal management. I see the point after whatching your vid a couple of times now :) Also I dont see any degradation on my ionique after 120'000kms and it all make sense. Looking forward for more tech vids ;)
Hello Spud 🙂
There are plenty of EVs that don't have radiators. Older and/or less powerful EVs use air-cooled motors and batteries for simplicity and cost reduction. Many electric motorcycles for example are solely air-cooled. It's only when you get to higher power densities and more expensive systems that you need water cooling (i.e. radiators).
Nissan Leaf is famous for not having a liquid cooled battery. BUT the Leaf has two radiators, one for AC and one for motor inverter and electronics!!
@@smartelectriccar I think most ppl think they're the same some reason.
@@smartelectriccar ...and electronics, what specifically would be included under this term? motor, inverter and? Thanks in advance!
@@smartelectriccar the Leaf is famous for having the batterys fail after 5yrs in hot climates, like here in Oz.
Brilliant as usual Richard.
Coming to see you next month about conversion on an MGZT.
How do we make an appointment?
Jules75ZT
Would love an in depth video on the Tesla LDU cooling - specifically the rotor seal, many reports of these failing and complete drive units required.
Brilliant :D
You've got me saying if you like now 😜 great vid 👍 Any tips to keep a Tesla SDU cool?
Yes. Separate the cooling for the motor and inverter with separate systems.
@@ElectricClassicCars thanks chaps 👍
@@ElectricClassicCars Would battery cooling be a third separate system or incorporated into the motor OR inverter system?
A heat pump is not the reverse of a fridge ! It's exactly the same as a fridge, you just use the inputs and outputs differently....
So how does cold weather ie freezing nights effect the charging or even your not charging?
Does a tree falling over in the forest make a sound if nobody is around to hear it?
If you're charging and it's below freezing, the battery gets warmed.
@@defectivedegenerate4046 Nobody ever mentions how much range ICE vehicles lose in winter. It's easily 60-70% for short-range city driving and 20-30% for highway driving once it gets into the -25-35 Celsius range. It was a lot worse before I installed a trickle charger on the same plug as the block heater. It takes at least 10 minutes until the defroster works, 10 minutes until the car warms up enough to run efficiently, and before the trickle-charger, 10 minutes on the freeway to recharge the battery. Plus the fact that the an ICE vehicle is a few dozen times more likely to need repairs in this weather than it does in the summer. I mostly walk to work, but almost 2/3 of my gas consumption is in January & February. That's with a heated garage.
Can you do a video on 12V batteries on EV's?
Yes, that's a good topic. Lots to say on that. 😁👍
Any plans for type of heating system review (car interior heating)?
It might be interesting what is modern heating systems for EV and it's efficiency.
Can a mazda rx8 swap his engine with an electric with 500 hp
Great explanation l open to anything involving electric vehicles another joke Harley Davidsons the most eficent way of turning petrol into noise without the benefit of horse power
I read in an article that by charging your electric car with a granny cable you loose up to 30% of energy by losses in the cable and connections. Is that true? That would be not so ideal with the high energy prices these days.
If i would spill 30% on fueling up my petrol car every time that would be a big puddle of fuel🤔
Don't think about how much of your fuel is being turned directly into waste heat without contributing to forward motion then!
30% seems like a lot. Most space heaters run at the max safe output of a wall socket. 30% of the heat from a space heater directly into an electric cable would likely melt the insulation on the cable quite quickly. That 30% figure doesn't seem to survive a logical look at it.
@@Surestick88 maybe they calculated with 20 meter/60 ft cable. In that case you have a long distance where the heat can escape without burning up the insulation. But i think the losses are not just in the cable. There are also losses bij converting the ac current from your socket to dc current for the batteries. But yes 30% sounds pretty questionable.
Maybe Richard has something to say about this.
Whenever you transport and/or convert electricity there will be losses. There are inherent losses in chargers as they convert from AC to DC, which is why the onboard chargers need to be fooled to deal with that wasted energy in the chargers inefficiency that's turned into heat. The amount of losses depend on temperature and voltage. For instance the Nissan Leafs charger is about 92% efficient in 240v countries but 120v countries it's more like 85%.
@@ElectricClassicCars thanks for answering 👍
You spill the fuel simply by moving the fuel from the refinery. The truck moving it uses fuel that could in theory have been put into the gas station's fuel tank. That is all spillage. That's a lot of fuel spread out over a lot of cars. It's also a reason that a "gallon" of electricity is much smaller than its equivalent, and as such, it has already been removed in the efficiency ratings. What moves the electricity? High voltage transmission wires.
EVs are a technological miracle in comparison to ICE.
Hello mate
What about AC? Needs a radiator.
Called a condenser.
@@TC-V8 What's the difference?
Great advantage of having an electric car: in winter, not having to check under the wings or the bonnet for cats seeking the residual heat
I've made the same comment in response to other posts, but ICE vehicles lose a $^!#-load of range in our Canadian winters. At -20 Celsius, I need to idle my car for 10 minutes to run the defroster, drive for 10 minutes to warm up the engine to run efficiency, and then drive 5-10 minutes on the freeway to recharge the battery to drive to the grocery story 500 meters away. (I installed a trickle charger on the same plug as the block heater to avoid the freeway recharging run.) Below -30 Celsius, change that to 15 minutes to defrost, 15 minutes to warm up the engine, and 15 minutes on the freeway to recharge the battery. And when it gets really cold, the defroster will never work, the car will never warm up & good luck recharging the battery. Then there's the cold weather repair bills. We spent over USD$ 6,000 insulating & putting a natural gas furnace in the garage to keep it at 4 degrees Celsius. Our cars haven't needed any winter repairs several years in a row now. It's already paid for itself. When I lived in an apartment & parked outside, I lost over 80% of my range in the winter. With the heated garage, I only lose 30%-ish. Plus there's the whole holding-a-gas-nozzle in weather where your hand gets frostbite in 30 seconds thing.
14:21 Cat?
The first and second law of Thermodynamics.
40 c is happy temperature for tesla
..... in my country in summer it reach 50 c ... so the engen can not get cold
I don't give a hoot or a toot about radiators.
The reason that cars need grilles at the front is because I LIKE THEM!!!!!!!!!!! Almost all modern cars are looking fugly, ESPECIALLY Electric cars! Therefore they all need proper front grilles in the design so that I like them!
I'm right and everyone else is wrong! Bugrit bugrum!
I used to feel the same way but now the times are changing and I feel like a grill for the sake of it is like a fake exhaust tip 🤮.
@@benellis7427 Hehe, so you're included in "The Wrong" from now on. 😛
You're double counting. Friction can only be lost as heat energy, unless you have cat-fur bearings 😂
Cat-fur bearings are getting more and more difficult to find nowadays. 😆😁👍
If this is so why are all manufactured electric cars designed to look like boiled sweets?
Why are all new cars designed with a jelly mould?
Why are all new cars #%^* crossovers?
1000th like.
11:19 😂 man, Tesla just joke
thats the time when I liked BMW.....but never was great fan. Please, convert an american Landyacht
The EV evangelists preaching gearboxes and radiators as unneeded only to be found lacking because of these assumptions.
EVs suck at Bonneville because they don't pump any air. And EVs suck on road because they don't have reciprocating flywheels.
Relying on bigger heavier batteries rather than sound rotational physics is the major embarrassment of major automakers and hobbyists alike.
And part of the reason they need a mobile nuclear power plant to power them.
Crying shame to ruin a classic 3ltr BMW with an electric motor. Think I'd rather see it crushed than that
@@spudproductions7606 too right. There's plenty shit cars around to stick leccy motors in. Why ruin a classic racer like the Beemer?
The car was crap on a good day - assuming it would start.
@@deetesmin if you don't like, don't watch.
@@Mardy72 I didn't 🤣
@@deetesmin ....take a hike then. Go trash talk someone else's comment section.