It surprises me they didn't install any current/voltage sensor at the output of the receiving antenna (embedded in the car). Then, with the power quality analyser at the input of the power conversion cabinet, you can calculate accurately the efficiency. There is too much uncertainty in this test to have a decent measurement.
Depends how much money the company that makes the charger decided to spend on the Transformer and the charging DC/DC converter. As a retied EE I can assure you that the more you spend on transformers, the more efficient they are. And DC-DC converters are notorious inefficient. We agonized over efficiency vs meeting the marketing targeted sell price point. Remember, a DC-DC converter is really a DC-AC-DC converter.
@@roland9367 I should have been a little clearer. There are Isolated, Liner, Buck, Boost, and Flyback, etc. converters. Usually a DC-DC converter converts the DC to AC, steps it up/down through a transformer, then coverts in back to DC. The main issue with any type of power conversion is the on resistance of the switching MOSFETs. The lower the on resistance, the more expensive they are.
@@disturbed4733 wired: 1 AC mains to DC (PFC + rectifier) and 1 DC - DC (isolated converter, DC - AC - DC) wireless: AC mains to DC (PFC + rectifier) and 1 DC - AC - airgap - AC - DC. Both ways are practically the same thing (1 airgap of a difference). Why would a wireless be much more efficient - I have no idea.
@@volodumurkalunyak4651 I wasn't talking about wireless vs conductive. I was talking about the efficiency of the charger(s), depending on how much money they spent on the components. Same apples to both charging methods. I've seen cheap circuits that have 40% efficiency and expensive circuits that have 97% efficiency.
@@disturbed4733 I get it: you dont really compare those 2 charging methods in the video. But 40% is way too low, only suitable for low power electronics (like an FM radio or charger for electric toothbrush). Cheap 40% efficient circuit - well, heatsinks to dissipate outher 60% (1.5x output power) aren't that cheap. Speaking about power electronics, cooling ain't free.
I-Pace battery temperature and power kW to battery are available in Car Scanner. It even shows charger current and charger voltage, can be useful for next video.
I don't believe a cable would be less efficient than wireless, but it could make sense if the cars transformer is more efficient than the fast charger's. Wireless (induction) is AC until the car converts it to DC for the battery, unlike a fast charger which converts the grid's AC to DC before the car
There's no way the induction charging uses 50Hz AC. There's an AC->DC->AC step in there too. Björn really needs to investigate what the reason for the efficiency difference actually is. Maybe the car was just heating or cooling the battery on the second charge? Maybe ABB's efficiency is bad? There's no way the charging cable could have dissipated multiple kilowatts of heat during the charging process.
@@celeron55 WPT for automotive is usually at 85kHz. There’s a 3-phase AC to DC step, then inverter to 85kHz AC, then air transformer (coil), then AC to DC at battery voltage.
This does not make sense? Does anyone have some insight? I mean, this should/could be replicated in a controlled environment? If this is true, we waste a lot of energy with cables.... But then again, I cannot imagine a cable being less efficient...
The ABB Terra 184 used for the conductive charging test has over 96 % efficiency at nominal output of 180 kW. Due the efficiency curve for the integrated AC/DC converter I would assume that the station is a lot less efficient at 40 kW. On the other hand the inductive charging pads have a peak output of 50 kW and therefore operated nearly the whole time at peak efficiency. Maybe a test with a 50kW station would help to even out the difference and also the charging curve must be aligned. That is something the modification of the car has resulted in I think. Never the less a interesting insight and I am curious for part 2: the rematch 😉👍⚡️
Wow, astonishing. Recently I had a chat with someone claiming we need more than double the PV and wind energy to do wireless charging compared to charging with a cable. I said wireless EV charging is close to cable-charging when it comes to efficiency. So I will recommend your video with a big 😀in my face!
Well, measuring converter efficiency is unfortunately much more complicated that this and "100% accurate" power quality analyzer with rogoswki coils is hardly the device of choice for any efficiency studies, regardless of the decimal points that equipment might display. Charging converters are usually delivering +95% efficiencies on full load and well over 90% even at partial load. Efficiency is important factor to consider but also so easy to measure wrong.
I've been thinking about this. The parking lot has 50 charge pads but only 10 power supplies. No need to move your car if all 10 are occupied, yours will automatically start charging when somebody else stops, or the app will ask: "Hello, your car is 75% charged, would you like to stop and give charging for the next in line who has only 2% battery left. Yes, No?" When more and more people want to charge and lines get longer just add more power supplies as needed.
Awesome coverage, Norway leading the EV-way. Just imagine an inductive supermarket parking lot. Hoping for a chat with the guys at InterTraffic in Amsterdam next week.
Very good video Bjorn!! Being in Canada, I was wondering how the wireless system performed in winter ... and you answered it! Amazing system. I which we would have this system here!!! Regarding the efficiency of cable charging, I know that there is heat losses in the cable because here in winter, The cable sinks in the snow while charging at 9KW at my house. Losses must be proportional to charge power I guess. Looking forward for the part 2 with an OBDII charge & battery heater reading!!!
very interesting. And yay! for seeing an IPace (as I own one). The IPace regularly seems to be used as a test bed for various tech tests, everyone seems to want to make it more efficent or easier to charge. Maybe because of the high consumption :D
I looked at my Level 2 charging to see efficiency as I have a system that monitors our Condo’s house power used to charge EV’s in the building. I also have Teslafi data to see how much went into the battery. Level 2 is at 93% efficiency and 300 feet from the electrical room. Surprised the wireless charging wasn’t too far off level 2 kinds numbers. Interesting video!
There may be other variables… but at least the take home message is that that inductive charger (others may vary) is not less efficient than cable charging. 👍
Wow. This is a bizarre result. Only thing I can think is wireless was done with no battery heater the entire time and wired was heating the entire time. It doesn’t make sense that wired would be less. At the worst, the same. But wireless charging is looking mighty good!
Did you compare idle power for both setups? I do onderstand that the DC wired charger has more systems active compared to the wireless. Also, as the DC charger is running at only 25% of its capacity I can understand that it is not operating in its designed efficiency range and thus some energy is lost due to stepping up de AC voltage and converting to DC. The wireless pad seemed to be charging at its optimal designed capacity (>80%)
Maybe the cars transformer is more efficient than the fast chargers, because wireless (induction) is AC until the car converts it to DC for the battery, unlike a fast charger which converts the grid's AC to DC before the car
Resonance based transition is normally more efficient than regular, so the result is consistent (though "loses" seam a but too high, definitely car is doing something as well)
The efficiency also depends on the rated power of the charger. A 180 kW charger delivering 30kW may be less efficient than a 50kW charger delivering 45kW. For an Apples to Apples comparison this test should be performed at a 50kW DC charger and this 50kW wireless charger...
What a surprise! I thought inductive charging is slower and more ineffective. On this high SoC/relative low speed it is inverse. But how will it perform on low SoC and high charging speed?
This looks absolutely amazing, however 99.99 nein nein nein percent of people won't care less about the finer details like what the battery is actually taking. They just want to charge and go.
I was involved in an apples to apples laboratory comparison of DC and WPT charging a few years back. DC had 94% against WPT with 93% efficiency. (Reposted because my first comment disappeared)
@@koma-k Air gap was 15cm. Misalignment of ±10cm in x a y direction and ±1.5cm in z direction leads to a minimum efficiency of 90% at maximum misalignment and nominal power. One thing to note though, the maximum transfer power of the WPT system was 40kW compared to 50kW for D.C. using the same power electronics. This is because the WPT system is designed for the above mentioned misalignment.
@@panemetcircenses6003 thanks, nice to have some proper numbers! I think +/-10cm is still on the optimistic side for people parking, unless there is some sort of guidance system (an oversized pad housing and internal x/y articulation is probably the most practical solution - as seen in some Qi phone chargers). Do you have numbers for larger misalignments too?
@@koma-k positioning assistance systems are common, either with cameras or using low power excitation with the primary coil’s magnetic field. From 10cm plus the efficiency drops rapidly. At +12cm it’s at 85% and drops towards zero at +15cm. This is partly design though, greater tolerance could be design in at greater cost and decrease max. efficiency. My point of view is, as mobility moves towards greater autonomy and sharing, WPT will become more common.
2 reasons I could estimate 1- Have you considered the fact that there must be a different inverter between receiving pad in the car and the battery. 2- losses in the way from charging CCS port to reach to the battery… a lot of cabling in the car
Many folks look at plus measuring to the port. This was at attempt at measuring to the battery by looking at the SoC as an unbiased output. The test was done the prior week with a smaller delta on the SOC snd in reverse order to try to account for battery heater. The result was the same any way we looked at it, ie plug took about 15% more energy the wireless to achieve the same delta SOC.
Interesting results. But they need to connect the wireless charger to the BMS better, as the car manufacturer has decided that the battery is healthier being charged at the slower rate.
I'm wondering about pad alignment and car size. A couple cars not in the best spot, besides poor charging, could throw off anyone else on adjacent pads. Or maybe this is one way to get people to actually park well.
(Watched half-way so far) I don't think BMS would screw up. Perhaps it's amps limited, and if charging pad can provide more voltage, perhaps it still allows higher output?
The current would be likely be the limit but as the cable charger is able to deliver over 100kW (I don’t remember the exact number) this is not the problem.
@@oozkfrom the video, BMS rated current was not mentioned. The cable size also was not investigated. The discusssion was still wide open. The power station may provide big power but the charging station may not be ready enough to deliver the power. Generally, I believe cable charging is more efficient
The question or even the correct test to perform now would be at low soc. The wired charger should outperform the wireless charger. assuming the wireless charger delivers around 50kw/h even at low soc?!
I remember having heard this predicted. Do not forget cables need to be cooled or very thick. With wireless charging there is no lossy conductor. With wireless charging you have AC or actually high frequency charging and there is a transformer and impedance matching. With DC charging there is no transformer. Battery voltage and amperes are not optimally matched to the DC voltage and amperes that come from the charger. Here come the losses. A radio guy could tell you transmitting a radio wave has more range than putting that same radio wave through a cable tv network and all the cable amplifiers can easily consume more power than transmitting directly from an antenna.
So you replace a 2 m cable which you believe to be very lossy for some reason by two considerably longer cables, lay them in circles to from coils, align them with the precision you can park a car, put the AC-DC-converter in the vehicle and expect better efficiency?
The wired charger is quite a few meters further away from that transformer station, and we don't know if the cables used in the ground are the same for both chargers. Possibly that causes a higher loss?
Great test! I'm not surprised at all: Momentum Dynamics knew that their efficiency would be scrutinized avidly, so they put a lot of effort into maximizing efficiency of the conversion. In contrast, I'll bet the conversion-electronics of many wired chargers are garbage...
my guess is that the slow speed of the wired charging is the culprit Most chargers are not particularly efficient with low load scenarios. like lets say the module is designed to push 100kw and you only pull only 32kw ... at ~30% load most chargers are not really that efficient (gets way worse the lower you go, so 32kw on a 150kw charger will waste even more)
Imagine one day in the city having only to park to charge. No cables, no contact, no queque, no time needed. While you jump out the car it's already charging, until you jump in it again and go. In TB terms: no more gangbangs!
This was interesting, but in the end as the consumer i just care for what the company charges me, not what they lose on the way into my car. The benifit here would be chargingspeed?
My guess on the difference is based on the assumption that the charger management of the wireless system is directly attached on the battery itself and there is not need for a long cable (from battery to the rear of the car). if my guess is correct the efficiency on a model 3 should be a lot differente with the cable because as you may see for yourself in the Munro's videos the clabling system of the test is far more superior in term of efficiency My 2 cents
Great contect. But we simply have to many unknown variables in this test. Would have been great if you were able to reduce the number for unknowns in a new test later :)
Each ground pad is capable of reaching 75KW (dependent on car battery voltage and BMS). We then deploy into multiples of 75KW for larger vehicles (2, 4 or 6 pads per vehicle). So 450KW is our current top end.
Could be useful for busses since they stop often and at regular stops. But for cars, it's not worth it since it's more expensive and takes away range because less batteries can fit inside the car. In summary, wireless charging will not replace cables any time soon.
I think the method has too many unknowns. Of course the grid measurement is flawless but deriving transferred kWh from a SoC difference is rather inaccurate. As mentioned below there are many possible "auxiliary" drains, the battery was at different temperatures and so on. A classical power in/power out test would reveal more, as you are already planning. That said, comparing the power in their app and that of the net meter also resulted in 86% efficiency. I'm thinking the inductive pad might not communicate the correct power limit from the BMS, resulting in rather impressive but possibly unhealthy charge power at high SoC levels. Maybe there's a regen and fast charge limit and they use the regen one? Or it's just some conversion error.
@@bjornnyland yeah I know Bjørn bit it could be cool, just like you said, you have the app, and could enter service mode.. Thx for some very good videoes..
depends on how each is implemented and the context they're in. a very long cable will lose power to resistance where something like high power infrared may lose less. in this case and especially at these voltages it's highly unlikely wireless will even match wired let alone beat it
Unless they use really cheap cable, it should be more efficient than wireless. I remember measuring the efficiency of first generation Qi phone wireless adapter, it was about 60%.
I think the problem is 70-90.... I do not think that if you charge from 70->90 and then drive back to 70 and then you are on the same spot as you were in beginning. The same percentage interval could be different battery capacity level and different capacity. I think you should try to do both way of charging from 0 to 100. or (much faster) tamper the car a little bit and measure the power going to the battery while charging. It is just about to install current clamp and get to high voltage in system (find some high voltage distribution point). And instead of doing measurement based on capacity/energy delivered to battery you will quickly measure the power going though. Compare these two numbers and you have efficiency without long waiting. Just do it! Anyway thumbs up, this is science, sometimes it is hard to get proper results. Even you well prepared all experiment you got to wrong result. It also counts.
This test is not very useful. In my oppinion what happened is because the wireless charged much faster, the voltage was higher, thus the BMS estimated 90% "too early". Therefore less energy had to be delivered to reach 90%. It is highly unlikely that wireless charging is more efficient than hooking up a cable, it just doesnt make sense from my technical understanding. There is some other incorrect information in the video. That is that the BMS can limit the charging rate. That is not true, since the battery is directly hooked up to charger while DC charging. The BMS can only tell the charger to reduce the charging speed and then the charger reduces the charging rate. My guess is that the wireless pad doesnt receive any communication of the BMS of the car, it just charges the battery as deemed correct.
Wireless charging can also be done when the car is moving if you imbed induction coils in pavement. This really is the best solution for long haul trips, don't even have to stop... just charge as you go. This will also reduce the requirement for having oversized battteries.
Something is definitely wrong here. Ether battery condition was differ or car charging software is buggy, or something wrong with the chargers, but why charging in one case should be slower than other? In both cases car charger should limit charging power the same. And of course the weaker charging power, the less effective it is, because of all other than battery power consumption to battery charging power ratio is higher.
Well you’re running a 180kW charger @ 20- 30kW. I’m not surprised it’s not operating at optimal efficiency. You need to do this test again at a much lower state of charge with a car that can take the full output. Like a Taycan. You also need to work out why the BMS is allowing much faster charging from the wireless charger. Even work out if you might be damaging the battery.
BTW - that doesn’t mean that the wireless charging is less efficient, just that the test parameters left a lot to be desired. For example why 70 - 90% - that’s not a typical charging situation. 20- 80% would seem much more typical and the cynical part of me says the guys behind the wireless charger chose that range because it was best for their case.
Why are you measuring between the grid and output of the charger? How will that show the efficiency of the power delivery method? That will only show the efficiency of the charger it’s self. You would need to measure between the charger’s output power and input power of the car’s battery. Also, doing the test when the battery is at 70% and charging it to 90% is pointless as many chargers throttle the power output when the state of charge reaches 80% to protect the car’s battery’s lifespan. Do the test at a lower starting battery level.
If you want to compaire wirelless to wired charging, you are gone need much more data. especially the powerloss that happens from the cable of the transformor to the inductors (ground and car) The transformer of the wirelless charger is probaly way more expensive --> more efficient The transformer of the wire charger is probably less efficient because they cheaper made, the owners of the wire chargers doesn't have to worry to much about efficientcy because they can charge for the electricity that is used and not the electricity that is transformed. (the wirelless charging company it's biggest challenge is efficientcy, so they pay a bit more for transformers now to get a good image from the "public", and then they start cutting cost) The car was maybe programmed to be more economical when charging wirelless: (optimised for wirelless charging and not for wire charging) they maybe even programmed the car to use more power when wire charging. They maybe choose that wired charging station because they knew they are less efficient Just remember this COMPANIES WILL ALWAYS TAKE THE BEST SENARIOS FOR THEMSELVES (so if my english is bad, it's not my first language)
Man the future for the kids is gonna look insane. Electric cars, wireless charging, virtual reality. Space flights. We are really born to early. Perfect to be born in 2040. And live to 2140.
Wireless charging is inductive charging. A transformer is very good at transferring energy from one coil to another. One coil is in the road, the other on the bottom of the car. This is how all cars, trucks, and buses will be charged soon. Peace on earth, Peace in Space.
It surprises me they didn't install any current/voltage sensor at the output of the receiving antenna (embedded in the car). Then, with the power quality analyser at the input of the power conversion cabinet, you can calculate accurately the efficiency. There is too much uncertainty in this test to have a decent measurement.
Depends how much money the company that makes the charger decided to spend on the Transformer and the charging DC/DC converter. As a retied EE I can assure you that the more you spend on transformers, the more efficient they are. And DC-DC converters are notorious inefficient. We agonized over efficiency vs meeting the marketing targeted sell price point. Remember, a DC-DC converter is really a DC-AC-DC converter.
What do you mean a DC-DC converter is really going through AC as well?
@@roland9367 I should have been a little clearer. There are Isolated, Liner, Buck, Boost, and Flyback, etc. converters.
Usually a DC-DC converter converts the DC to AC, steps it up/down through a transformer, then coverts in back to DC.
The main issue with any type of power conversion is the on resistance of the switching MOSFETs. The lower the on resistance, the more expensive they are.
@@disturbed4733 wired: 1 AC mains to DC (PFC + rectifier) and 1 DC - DC (isolated converter, DC - AC - DC)
wireless: AC mains to DC (PFC + rectifier) and 1 DC - AC - airgap - AC - DC.
Both ways are practically the same thing (1 airgap of a difference). Why would a wireless be much more efficient - I have no idea.
@@volodumurkalunyak4651 I wasn't talking about wireless vs conductive. I was talking about the efficiency of the charger(s), depending on how much money they spent on the components. Same apples to both charging methods. I've seen cheap circuits that have 40% efficiency and expensive circuits that have 97% efficiency.
@@disturbed4733 I get it: you dont really compare those 2 charging methods in the video. But 40% is way too low, only suitable for low power electronics (like an FM radio or charger for electric toothbrush). Cheap 40% efficient circuit - well, heatsinks to dissipate outher 60% (1.5x output power) aren't that cheap. Speaking about power electronics, cooling ain't free.
I-Pace battery temperature and power kW to battery are available in Car Scanner. It even shows charger current and charger voltage, can be useful for next video.
I don't believe a cable would be less efficient than wireless, but it could make sense if the cars transformer is more efficient than the fast charger's. Wireless (induction) is AC until the car converts it to DC for the battery, unlike a fast charger which converts the grid's AC to DC before the car
There's no way the induction charging uses 50Hz AC. There's an AC->DC->AC step in there too. Björn really needs to investigate what the reason for the efficiency difference actually is. Maybe the car was just heating or cooling the battery on the second charge? Maybe ABB's efficiency is bad? There's no way the charging cable could have dissipated multiple kilowatts of heat during the charging process.
@@celeron55 WPT for automotive is usually at 85kHz. There’s a 3-phase AC to DC step, then inverter to 85kHz AC, then air transformer (coil), then AC to DC at battery voltage.
This does not make sense? Does anyone have some insight? I mean, this should/could be replicated in a controlled environment? If this is true, we waste a lot of energy with cables.... But then again, I cannot imagine a cable being less efficient...
The ABB Terra 184 used for the conductive charging test has over 96 % efficiency at nominal output of 180 kW. Due the efficiency curve for the integrated AC/DC converter I would assume that the station is a lot less efficient at 40 kW. On the other hand the inductive charging pads have a peak output of 50 kW and therefore operated nearly the whole time at peak efficiency. Maybe a test with a 50kW station would help to even out the difference and also the charging curve must be aligned. That is something the modification of the car has resulted in I think. Never the less a interesting insight and I am curious for part 2: the rematch 😉👍⚡️
Wow, astonishing. Recently I had a chat with someone claiming we need more than double the PV and wind energy to do wireless charging compared to charging with a cable. I said wireless EV charging is close to cable-charging when it comes to efficiency. So I will recommend your video with a big 😀in my face!
Well, measuring converter efficiency is unfortunately much more complicated that this and "100% accurate" power quality analyzer with rogoswki coils is hardly the device of choice for any efficiency studies, regardless of the decimal points that equipment might display. Charging converters are usually delivering +95% efficiencies on full load and well over 90% even at partial load. Efficiency is important factor to consider but also so easy to measure wrong.
180 charger inside a city...we struggle to find a 50 kW funcional charger...veeeery interesting one Bjorn and company.
I've been thinking about this. The parking lot has 50 charge pads but only 10 power supplies. No need to move your car if all 10 are occupied, yours will automatically start charging when somebody else stops, or the app will ask: "Hello, your car is 75% charged, would you like to stop and give charging for the next in line who has only 2% battery left. Yes, No?" When more and more people want to charge and lines get longer just add more power supplies as needed.
Björn: Wireless charging is the most inefficient
Hydrogen Car: Hold my Beer 🍺
19:49 shows 93% efficiency, this is better than I suspected
Awesome coverage, Norway leading the EV-way. Just imagine an inductive supermarket parking lot.
Hoping for a chat with the guys at InterTraffic in Amsterdam next week.
Very good video Bjorn!!
Being in Canada, I was wondering how the wireless system performed in winter ... and you answered it! Amazing system. I which we would have this system here!!!
Regarding the efficiency of cable charging, I know that there is heat losses in the cable because here in winter, The cable sinks in the snow while charging at 9KW at my house. Losses must be proportional to charge power I guess.
Looking forward for the part 2 with an OBDII charge & battery heater reading!!!
Wow - extraordinary results! Thanks Bjorn!
I was also amazed. Would have thought that it would be other way around and wireles would have much greater loss.
very interesting. And yay! for seeing an IPace (as I own one). The IPace regularly seems to be used as a test bed for various tech tests, everyone seems to want to make it more efficent or easier to charge. Maybe because of the high consumption :D
I looked at my Level 2 charging to see efficiency as I have a system that monitors our Condo’s house power used to charge EV’s in the building. I also have Teslafi data to see how much went into the battery. Level 2 is at 93% efficiency and 300 feet from the electrical room. Surprised the wireless charging wasn’t too far off level 2 kinds numbers. Interesting video!
I like wireless charger because it very clean and you don't need to grab anything or touch something like a wire charger.
There may be other variables… but at least the take home message is that that inductive charger (others may vary) is not less efficient than cable charging. 👍
Wow. This is a bizarre result. Only thing I can think is wireless was done with no battery heater the entire time and wired was heating the entire time. It doesn’t make sense that wired would be less. At the worst, the same. But wireless charging is looking mighty good!
Did you compare idle power for both setups? I do onderstand that the DC wired charger has more systems active compared to the wireless. Also, as the DC charger is running at only 25% of its capacity I can understand that it is not operating in its designed efficiency range and thus some energy is lost due to stepping up de AC voltage and converting to DC. The wireless pad seemed to be charging at its optimal designed capacity (>80%)
Not what I expected! Thanks for this real world testing!
86% is incredibly high considering it was needed to convert from AC to DC from the grid + charge the battery
Maybe the cars transformer is more efficient than the fast chargers, because wireless (induction) is AC until the car converts it to DC for the battery, unlike a fast charger which converts the grid's AC to DC before the car
Bjørn: "by the way…“
Also Bjørn: talks about something totally unrelated.
Always cracks me up 😂
Resonance based transition is normally more efficient than regular, so the result is consistent (though "loses" seam a but too high, definitely car is doing something as well)
The efficiency also depends on the rated power of the charger. A 180 kW charger delivering 30kW may be less efficient than a 50kW charger delivering 45kW. For an Apples to Apples comparison this test should be performed at a 50kW DC charger and this 50kW wireless charger...
Perhaps the cable above ground is colder than the underground cable to the inductive charge pad.
We need to see the same with OBD :P
What a surprise! I thought inductive charging is slower and more ineffective. On this high SoC/relative low speed it is inverse. But how will it perform on low SoC and high charging speed?
Virkelig super spændende projekt 😊 tak for nogle fantastiske videoer - keep them coming 😊☀️👌🙏
This looks absolutely amazing, however 99.99 nein nein nein percent of people won't care less about the finer details like what the battery is actually taking. They just want to charge and go.
Which calculator app were you using on your phone when car charging was completed?
Nice job guys!
I was involved in an apples to apples laboratory comparison of DC and WPT charging a few years back. DC had 94% against WPT with 93% efficiency. (Reposted because my first comment disappeared)
How precise was receiver placement over the pad, and how big was the impact if it was e.g. 10cm or 20cm off-centre? And how big was the air gap?
@@koma-k Air gap was 15cm. Misalignment of ±10cm in x a y direction and ±1.5cm in z direction leads to a minimum efficiency of 90% at maximum misalignment and nominal power.
One thing to note though, the maximum transfer power of the WPT system was 40kW compared to 50kW for D.C. using the same power electronics. This is because the WPT system is designed for the above mentioned misalignment.
@@panemetcircenses6003 thanks, nice to have some proper numbers!
I think +/-10cm is still on the optimistic side for people parking, unless there is some sort of guidance system (an oversized pad housing and internal x/y articulation is probably the most practical solution - as seen in some Qi phone chargers). Do you have numbers for larger misalignments too?
@@koma-k positioning assistance systems are common, either with cameras or using low power excitation with the primary coil’s magnetic field.
From 10cm plus the efficiency drops rapidly. At +12cm it’s at 85% and drops towards zero at +15cm. This is partly design though, greater tolerance could be design in at greater cost and decrease max. efficiency.
My point of view is, as mobility moves towards greater autonomy and sharing, WPT will become more common.
2 reasons I could estimate
1- Have you considered the fact that there must be a different inverter between receiving pad in the car and the battery.
2- losses in the way from charging CCS port to reach to the battery… a lot of cabling in the car
Many folks look at plus measuring to the port. This was at attempt at measuring to the battery by looking at the SoC as an unbiased output. The test was done the prior week with a smaller delta on the SOC snd in reverse order to try to account for battery heater. The result was the same any way we looked at it, ie plug took about 15% more energy the wireless to achieve the same delta SOC.
Interesting results. But they need to connect the wireless charger to the BMS better, as the car manufacturer has decided that the battery is healthier being charged at the slower rate.
Very interesting video 🙂
Thanks so much for taking time to shine a light on this. Very exciting potential in this technology that I've not seen covered more widely.
Interesting stuff 👍
Thanks a lot for this detailed test. We need to do more independent tests in the name of science
amazing... The car has to be retrofitted with some reception coils, right??
Yup.
Yes, a vehicle assembly receiver pad integrated under the subframe of the vehicle.
I'm wondering about pad alignment and car size. A couple cars not in the best spot, besides poor charging, could throw off anyone else on adjacent pads. Or maybe this is one way to get people to actually park well.
(Watched half-way so far) I don't think BMS would screw up. Perhaps it's amps limited, and if charging pad can provide more voltage, perhaps it still allows higher output?
The current would be likely be the limit but as the cable charger is able to deliver over 100kW (I don’t remember the exact number) this is not the problem.
@@Torben1411 The wired fast charger might have self imposed limitations on voltage that are lower than the car's...
@@oozkfrom the video, BMS rated current was not mentioned. The cable size also was not investigated. The discusssion was still wide open. The power station may provide big power but the charging station may not be ready enough to deliver the power.
Generally, I believe cable charging is more efficient
The question or even the correct test to perform now would be at low soc. The wired charger should outperform the wireless charger. assuming the wireless charger delivers around 50kw/h even at low soc?!
I remember having heard this predicted. Do not forget cables need to be cooled or very thick. With wireless charging there is no lossy conductor. With wireless charging you have AC or actually high frequency charging and there is a transformer and impedance matching. With DC charging there is no transformer. Battery voltage and amperes are not optimally matched to the DC voltage and amperes that come from the charger. Here come the losses. A radio guy could tell you transmitting a radio wave has more range than putting that same radio wave through a cable tv network and all the cable amplifiers can easily consume more power than transmitting directly from an antenna.
So you replace a 2 m cable which you believe to be very lossy for some reason by two considerably longer cables, lay them in circles to from coils, align them with the precision you can park a car, put the AC-DC-converter in the vehicle and expect better efficiency?
There’s still cables, maybe they use a higher voltage on one side?
The wired charger is quite a few meters further away from that transformer station, and we don't know if the cables used in the ground are the same for both chargers. Possibly that causes a higher loss?
But *that* much more loss? Really?
@@bjornnyland I don't know, but worth investigating?
If you want to know how hot the battery is, you could use a thermal scanner.
Thanks for sharing this
On the Hydrogenstation is still requries appointment to fill hydrogen.
Great test! I'm not surprised at all: Momentum Dynamics knew that their efficiency would be scrutinized avidly, so they put a lot of effort into maximizing efficiency of the conversion. In contrast, I'll bet the conversion-electronics of many wired chargers are garbage...
Could the extra power be going into the charging units cooling systems for the cables?
These cables are not water cooled.
ABC - Always Be Critical when comparing charging methods! Interesting as unexpected result and several questions. Try the OBD on a Tesla. Thanks!
Don't the wired power dispensers use liquid cooling for their cables. Could that be taking some of the power and so lowering the efficiency?
my guess is that the slow speed of the wired charging is the culprit
Most chargers are not particularly efficient with low load scenarios. like lets say the module is designed to push 100kw and you only pull only 32kw ... at ~30% load most chargers are not really that efficient (gets way worse the lower you go, so 32kw on a 150kw charger will waste even more)
Super interesting 👍 Track this down...😎
Imagine one day in the city having only to park to charge. No cables, no contact, no queque, no time needed. While you jump out the car it's already charging, until you jump in it again and go. In TB terms: no more gangbangs!
This was interesting, but in the end as the consumer i just care for what the company charges me, not what they lose on the way into my car. The benifit here would be chargingspeed?
Excellent first stab at comparing, will be great to see a retest, maybe with a vehicle you see the battery and bms better to get more accurate numbers
My guess on the difference is based on the assumption that the charger management of the wireless system is directly attached on the battery itself and there is not need for a long cable (from battery to the rear of the car).
if my guess is correct the efficiency on a model 3 should be a lot differente with the cable because as you may see for yourself in the Munro's videos the clabling system of the test is far more superior in term of efficiency
My 2 cents
i'm thinking the converters are more efficient at higher load..strange that it's loading faster when it's wireless though
Do I have a deja-vu? Is this Matrix?
What's the max output power (kw) these systems can provide?
75 kW for each plate. Bus with 4 plates can charge at 300 kW.
Great contect. But we simply have to many unknown variables in this test. Would have been great if you were able to reduce the number for unknowns in a new test later :)
This makes more sense with electric semi trucks
What is the maximum Power (KW) through wireless charging? And is it possible to add to any car?
50 kW per pad. Two pads (if you have space for it) would make 100 kW
Each ground pad is capable of reaching 75KW (dependent on car battery voltage and BMS). We then deploy into multiples of 75KW for larger vehicles (2, 4 or 6 pads per vehicle). So 450KW is our current top end.
Could it be that the SOC scale changed during the test? Maybe due to a dynamic top buffer and temperature changes?
Can I get that at home? How?
Imagine not even having to plug in when you get home. Really would love it.
Could be useful for busses since they stop often and at regular stops. But for cars, it's not worth it since it's more expensive and takes away range because less batteries can fit inside the car. In summary, wireless charging will not replace cables any time soon.
Wireless charging is used on CAF trams in Luxembourg.
I think the method has too many unknowns. Of course the grid measurement is flawless but deriving transferred kWh from a SoC difference is rather inaccurate. As mentioned below there are many possible "auxiliary" drains, the battery was at different temperatures and so on. A classical power in/power out test would reveal more, as you are already planning. That said, comparing the power in their app and that of the net meter also resulted in 86% efficiency.
I'm thinking the inductive pad might not communicate the correct power limit from the BMS, resulting in rather impressive but possibly unhealthy charge power at high SoC levels. Maybe there's a regen and fast charge limit and they use the regen one? Or it's just some conversion error.
Good test would love to see some more off them, and if the Company had snorker car to test with..
Take marcus Tesla to the test..
One does not simply just test it. It needs to get wireless charging pad installed + modify car's software.
@@bjornnyland yeah I know Bjørn bit it could be cool, just like you said, you have the app, and could enter service mode..
Thx for some very good videoes..
It would interesting to know how wireless pad is connect to the battery. Hooked up to the same wire from battery to the car flap?
Spliced into exactly the same standard DC charge equipment.
69%. That’s a nice number. Lmaooo
Maybe have a second identical ipace without the wireless pad
how the inductive coil is connected to bms?
any idea when you will get the chance to review the Lucid ?
Wireless charging can not be more efficient than via cable or am I completely wrong?
depends on how each is implemented and the context they're in. a very long cable will lose power to resistance where something like high power infrared may lose less. in this case and especially at these voltages it's highly unlikely wireless will even match wired let alone beat it
Watch the video to find out ;)
Unless they use really cheap cable, it should be more efficient than wireless. I remember measuring the efficiency of first generation Qi phone wireless adapter, it was about 60%.
You are right. There are only additional steps with additional losses.
@@Nelson-Man the steps for WPT and DC charging are the same.
Wireless charging is looking good. Bring on the future.
I think the problem is 70-90.... I do not think that if you charge from 70->90 and then drive back to 70 and then you are on the same spot as you were in beginning. The same percentage interval could be different battery capacity level and different capacity. I think you should try to do both way of charging from 0 to 100. or (much faster) tamper the car a little bit and measure the power going to the battery while charging. It is just about to install current clamp and get to high voltage in system (find some high voltage distribution point). And instead of doing measurement based on capacity/energy delivered to battery you will quickly measure the power going though. Compare these two numbers and you have efficiency without long waiting. Just do it!
Anyway thumbs up, this is science, sometimes it is hard to get proper results. Even you well prepared all experiment you got to wrong result. It also counts.
wow! super experiments
Longer charging time; car consumes more energy during charging…
It's insignificant.
Thanks for this very interesting video.
Looks promising and like "less is more".
The Hyundai brand seems to go for this
This test is not very useful. In my oppinion what happened is because the wireless charged much faster, the voltage was higher, thus the BMS estimated 90% "too early". Therefore less energy had to be delivered to reach 90%. It is highly unlikely that wireless charging is more efficient than hooking up a cable, it just doesnt make sense from my technical understanding.
There is some other incorrect information in the video. That is that the BMS can limit the charging rate. That is not true, since the battery is directly hooked up to charger while DC charging. The BMS can only tell the charger to reduce the charging speed and then the charger reduces the charging rate. My guess is that the wireless pad doesnt receive any communication of the BMS of the car, it just charges the battery as deemed correct.
The wireless charger is fully controlled by the BMS. JLR led the integration activity.
The wired charger claims it put 21,583kWh into the car which gives a charger efficiency of ~93%.
Wireless charging can also be done when the car is moving if you imbed induction coils in pavement. This really is the best solution for long haul trips, don't even have to stop... just charge as you go. This will also reduce the requirement for having oversized battteries.
Yup, and less battery = less weight = less consumption = more affordable cars = less fossil = me happy.
What I would like to see is a test on the RF and EMC emmissions from this. I know they will be meny 1000's of times higher than safty levels.
Input impedance of the car is changed by attach wireless adapter to it.
Bring the termokamera next time. Loss = heat
Something is definitely wrong here. Ether battery condition was differ or car charging software is buggy, or something wrong with the chargers, but why charging in one case should be slower than other? In both cases car charger should limit charging power the same. And of course the weaker charging power, the less effective it is, because of all other than battery power consumption to battery charging power ratio is higher.
Put 3 pads under a car able recieving such Energy, would be very interisting for a full charge vs cable
2pads would double the charge rate, 3->3x. but may not be enough space on the underside
Well you’re running a 180kW charger @ 20- 30kW. I’m not surprised it’s not operating at optimal efficiency. You need to do this test again at a much lower state of charge with a car that can take the full output. Like a Taycan. You also need to work out why the BMS is allowing much faster charging from the wireless charger. Even work out if you might be damaging the battery.
BTW - that doesn’t mean that the wireless charging is less efficient, just that the test parameters left a lot to be desired. For example why 70 - 90% - that’s not a typical charging situation. 20- 80% would seem much more typical and the cynical part of me says the guys behind the wireless charger chose that range because it was best for their case.
Why are you measuring between the grid and output of the charger? How will that show the efficiency of the power delivery method? That will only show the efficiency of the charger it’s self. You would need to measure between the charger’s output power and input power of the car’s battery. Also, doing the test when the battery is at 70% and charging it to 90% is pointless as many chargers throttle the power output when the state of charge reaches 80% to protect the car’s battery’s lifespan. Do the test at a lower starting battery level.
If you want to compaire wirelless to wired charging, you are gone need much more data.
especially the powerloss that happens from the cable of the transformor to the inductors (ground and car)
The transformer of the wirelless charger is probaly way more expensive --> more efficient
The transformer of the wire charger is probably less efficient because they cheaper made, the owners of the wire chargers doesn't have to worry to much about efficientcy because they can charge for the electricity that is used and not the electricity that is transformed. (the wirelless charging company it's biggest challenge is efficientcy, so they pay a bit more for transformers now to get a good image from the "public", and then they start cutting cost)
The car was maybe programmed to be more economical when charging wirelless: (optimised for wirelless charging and not for wire charging) they maybe even programmed the car to use more power when wire charging.
They maybe choose that wired charging station because they knew they are less efficient
Just remember this
COMPANIES WILL ALWAYS TAKE THE BEST SENARIOS FOR THEMSELVES
(so if my english is bad, it's not my first language)
We need to put on our thinking cap 🤔 💭 🤔
Man the future for the kids is gonna look insane. Electric cars, wireless charging, virtual reality. Space flights. We are really born to early. Perfect to be born in 2040. And live to 2140.
Great experiment. I would only suggest you to protect your balls with aluminium foil next time. Just in case mate!
Impressive sheeeeetttt!
I think a tesla is needed to confirm this. Something seems off.
20:10 right.
Wireless charging is inductive charging. A transformer is very good at transferring energy from one coil to another. One coil is in the road, the other on the bottom of the car. This is how all cars, trucks, and buses will be charged soon. Peace on earth, Peace in Space.
This is not showing that wireless charging is efficient since it is not, but it shows how badly designed the tested grid chargers are.