Hybrid and EV Regenerative Braking Systems

[@BPantherPink]

It would be an honor to just be in Prof. Kelly's class !! Such crystal clear and honest explanations.

[@WeberAuto]

Thank you!

[@jprates]

I don't know what I like the most: a) The way Prof. Kelly explains things making it so easy to understand, or b) The satisfaction to see someone truly loving its work as a teacher and the tech involved. The world would do a lot better if we had more Prof. Kellys teaching across all countries universities.

[@pj210210]

I am a Motor Vehicle Lecturer in England and I have found all of Prof Kelly's videos excellent, and use them extensively in my advanced Vehicle Technology classes. Keep up the good work John.

[@moi01887]

One thing I'd love to see - and pardon me if you've done this, I looked and didn't see it - is a discussion of the hydraulic braking system in hybrid & electric vehicles, and how the transition/combination of that and regenerative braking works. I get the sense there's some real wizardry there.

[@MbMax64]

As far as I know when you push the brake pedal and the vehicle slows, the energy released is dissipated in part in the brake calipers and discs and in part is converted in electric energy used to recharge the battery. The same phenomenon of the slowing down of the vehicle through the friction of the tires on the asphalt strengthened by the action of the braking system. Moreover I've heard that in some EV when you push the brake pedal the first part of the braking action is obtained through the increase of the load and therefore the increase of the regeneration driven by the inverter. Only after a certain increase in the pressure on the pedal the hydraulic braking system is called to work.

[@CGrantL]

It’s different in almost every car. Some have paddles to control the regen, some use the brake pedal as @MbMax describes. Some have “one pedal driving” that will let you stop and go with just the gas pedal with no traditional brakes. Almost all of them let you change how it works. If you want to see it for yourself you should go take a test drive. Much like a standard transmission, there’s good technique required to get maximum efficiency and smoothness

[@MacsPiano]

The hydraulic system is the same as a normal car. Once you reach a certain low speed or requires hard braking that the regenerative braking inside the transaxle can’t perform. That’s what happens. The hydraulic brakes take over once the pedal throw reaches down low enough. There isn’t regenerative transfer through the calipers or pads.

[@theinterfaithshepherd9075]

I've taken multiple physics courses and electrical engineering courses and never learned so much!! Great video!!

[@skylar767]

That was the clearest, most concise & easiest to understand explanation of EV/Hybrid regen braking I've heard. Prof Kelly, the, sound, video, graphic presentation, and your soft-spoken voice & manner made it a pleasure to watch. I'm looking forward to whatever is next on offer. Thx

[@SC-qx2kj]

Professor Kelly busted the myth about "B Mode". Many belief B mode uses the ICE piston compression to decrease the vehicle speed. This does not make any sense to waste the energy which otherwise can be easily recovered. Prof. Kelly clearly explained in B mode, a higher level of regenerative braking to (1) recover more energy to the high voltage battery and (2) the magnetic field puts a higher load to the spinning wheels so less hydraulic breaking is required. Today, I did an experiment with my 2020 Prius Prime PHEV in a 50 mile city driving test invloving mostly flat roads but with many traffic lights. Each time when I needed to slow down, I engaged the B mode until the braking effect diminished before using the hydraulic brake. The result was about 10-15% more range in one charge than not using the B mode at all. Thank you prof. Kelly for clearing this cloud.

[@pdhabets]

Hey Prof. Kelly, nice little model of a power plant (MG1), transmission lines (jumpers), and household loads (MG2) you've got there (@ 20minutes). Thanks for sharing!

[@WeberAuto]

Thank you

[@andrewjohnson4255]

This is fantastic. I've been at Toyota for about a year and a half now and kept asking what actually made the vehicle slow down during regenerative braking. Nobody could answer and I couldn't find it anywhere in our information. So thanks alot for finally making sense of it for me.

[@WeberAuto]

Thank you! I am glad it was helpful.

[@ClockworksOfGL]

If I had the money, I’d buy you a Tesla just so I could watch videos of you pulling it apart. Keep up the good work!

[@WeberAuto]

Thank you very much!

[@kens97sto171]

Bryan Noga Check out Rich Rebuilds on KZbin. He buys salvage Tesla's and gets them back on the road. He is NOT a technical guy... So don't expect the fantastic detail that this amazing channel gives. But if you want to see a Tesla torn apart.. it's a good place to start. I enjoyed watching it.. but it also. Made me NOT WANT a Tesla. Mostly because they won't sell you parts and don't really want people fixing there own cars...

[@2020tuber]

@kens97sto171, I think it's a bit more involved than just "not wanting people to fix their own cars". Extra parts means additional inventory space and logistics... Most ICE manufacturers have a big warehouse where they store the extra parts... Consider that Toyota stocks parts for any vehicle for about 10 years after they're manufactured...

[@oisiaa]

Absolutely! I can't wait for Weber to get a Model 3!!

[@motofan16]

Hah... Their motors are a bit different :)

[@laura-ann.0726]

I bought a 2019 Prius Prime on July 2, and have driven it about 800 miles. The explanation in this video of what "B" mode does is wonderful! When I am approaching a red light at 40 mph, and let off the accelerator pedal, the car slows down, and the power flow meter shows regen braking in effect. Pull the selector into "B", and the deceleration instantly increases substantially. The owner's manual says nothing about what's actually happening in "B" mode, and this video explains it perfectly! So, deceleration in "D" mode only uses MG2 for regen braking, but deceleration in "B" mode adds MG1 for additional regen braking. Prof. Kelly, I live in Sacramento, CA, and we get daytime high temps up to 115°F in the summer months. Is there enough cooling capacity in the P610 to keep the MG1 and MG2 stator coils within safe temperature limits in a climate as hot as ours gets? I try to drive in EV mode as much as possible, so I am giving those motor generators, and the battery, quite a workout. I am not sure yet how these stators are cooled. Are they submerged in the liquid transmission oil, or are they dry and cooled by air flowing through them?

[@nick8116]

They are submerged in ATF.

[@E.after.D.I.am.T.H]

Thanks a lot! That was some quality time spent on KZbin.

[@WeberAuto]

Glad you enjoyed it!

[@wphubert]

Professor Kelly, This discussion was an incredible presentation. Love the old mili ammeter and find it incredible that with induced low voltages of appx 3 volts the output motor gen actually turned. Your “student” body is not limited to just those that fortunate enough to attended Weber, but extends around the world to those from 9 to 90 and continues through the years. Thank you so much!

[@WeberAuto]

Thank you very much!

[@MaicSalazarDiagnostics]

Thx again for all your great videos professor. I love learning and hybrids are a lot of new fun.

[@WeberAuto]

Thank you!

[@kherchia73]

Always Awesome! Thank you very much9 ;-)

[@mariuscristianbuia148]

Dear Prof. Kelly , with this video you explain so much better about the fact that when you put a load on the GM 1 it will slow down the motor, a fact that i did't know , therefore i went to the patent lawyer but he didn't know how to explain why my invention it is not gonna work , he just told me that it simply is not working . Thank you very much !!!!

[@federicogioachini653]

Your videos are just SUPER, congratulations!! Just one note: in "B mode" MG2 will regenerate more power than "D mode", but that "extra-power" is not necessarily sent to the battery. In fact, MG1 can be used as a motor to speed up the ICE, dragging it, and use it as a brake. If battery SoC is 100% (the usable SoC, btw) "D mode" cannot guarantee ANY regenerative braking, while B mode can, since it can dissipate MG2 regenerated power through the ICE using MG1 to drive it F

[@jennifertingchaleun2637]

Thank you Prof. K for a thorough explanation of this complex system. I especially like the live demonstration to help me visualize the concept. I will have to watch this a few times to get a complete understanding. I find it very fascinating. Bravo. Thanks again.

[@WeberAuto]

Thank you!

[@RapperBC]

" I wonder what could've bent that milliammeter's needle so severely?" "Ahhh Iseenow..." (8^D) All kidding aside, a great demonstration. So many teachers dive straight into formulas, when electromagnetic principles are so easily and clearly shown.

[@WeberAuto]

Thank you! Yes, that poor milliammeter had endured years of abuse ;)

[@palmino22]

Thank you sir . Even guys who do not have the basics of electrical or electronics will get an idea of the working principle of Hybrid EV RBS. Outstanding explanation.

[@georgecostanza2695]

Professor Kelly, you’ve got me wanting to move to Utah just so I could enroll in your program! Keep doing what you’re doing, the way you’re doing it!!

[@WeberAuto]

Awesome! Thank you!

[@raymundhofmann7661]

Regenerative braking with permanent magnet synchronous machines works with the inverter applying a pulse width modulated voltage usually well above 10 Khz which approximates the motors AC voltage usually well below 1KHz being synchronous to what it would look without electrical load and with a 90 degree lagging current proportional to the braking (negative) torque desired. It is just the opposite as generating power where the phase of the AC current is leading 90 degrees for positive torque. This in effect uses the motor inductance as a transformer / step up converter so 20V rms with slow rotation as seen can charge a battery with 300V, same as when generating power, just with opposite sign. For this it is necessary for the inverter to know the motor position so it can apply the current in the proper frequency and phase, which is usually done by a additional mechanical rotational sensor. And this is the convenient thing about most kind of these motors, they are basically electrical transformers with added mechanical features.

[@michaelgalvin1024]

Thankyou so much, I can’t put into words how much I am enjoying your teaching. I teach Automotive technicians at a technical college in Sydney, Australia, TAFE and you are inspirational. Thankyou

[@WeberAuto]

Thank you very much! it is always good to hear from another automotive teacher!

[@Theshadow888]

this is the shortcut of all other youtube videos regrding this topic... great work sir

[@WeberAuto]

It's my pleasure

[@scrubscrout]

Great video! One comment on demonstrating how adding a load slows down the vehicle is that in your example the motor was acting like a generator and was converting the rotational kinetic energy of the rotor into electric current which was being converted into heat in the resistor. On the vehicle the kinetic energy would be converted to electric energy and stored in the battery. Thus the kinetic energy is removed from the car in the form of electricity and slows down the car.

[@ldesaul]

Great breakdown and explanation of regen. I always drive my Bolt in L, rarely use the brakes. On the flip side, I doubt I will get many miles out of my front tires! Yes, I rotate every 5k miles.

[@WeberAuto]

Thank you. Keep the tire pressures correct or even a little high.

[@takeiteasy6154]

Thank you professor for spreading the knowledge to far and wide, best wishes from London. Your videos are absolutely brilliant and easy to grasp.

[@WeberAuto]

Thank you very much!

[@onlyfoolslads7844]

What an amazingly talented guy, 👍

[@WeberAuto]

Thank you very much

[@profdmiranda]

I just bought a Prius V this past week. I have been searching for information about how it works, mainly the regenerative braking, and this is the best technical explanation I have found. Thanks for the information and all the effort invested on it. I just subscribed. 😊

[@kyhonjan]

Thank you for this video and the hundreds of other very high indepth technical videos in your channel. I am no engineer but understanding rc electronic i believe there is a limit on battery regeneration depending on the charge state and temperature. This would in some cases like long inclines limit the regenerative force to protect the battery. In these circumstances to prevent brake fade the MG2 energy is diverted to MG1 which then drives the ICE. Of course the fuel and ignition is inhibited but the drag of the ICE compression provides the bulk of the braking force. I would guess the ICE rpm is varied to provide the commanded brake force.

[@WeberAuto]

Thank you

[@ronremillard776]

You have a wonderful gift for making the incredibly complex simple. I have very little aptitude for mechanics, but your explanations provide a very clear understanding of how things work.

[@jamesbruce1183]

The configuration of the magnets affects the magnetic flux and so the voltage. That's why it is not a sinewave. To simulate a load you can also short the windings. The rotor will be really hard to turn even by hand.

[@WeberAuto]

Thanks for the information. Yes, shorting the stator windings makes it stop rotating

[@8953147]

Great video on how generators work, especially smoking the resistor!

[@WeberAuto]

Thank you very much! It was fun

[@jaimelima2420]

Thanks Prof. Kelly. Really good explanations. BTW, minute 6:00 it becomes clear why that amperemeter needle is kind of bent like a bow!

[@rodwall2335]

Hi John, a great video. An idea I have is a demo to show how the Power Split Device splits power. (1) Put your electric drill in place of the ICE. (2) Put a small electric load resistor on MG2. (3) then put a load resistor onto MG1. (4) note the power going to MG2 with a volt meter. (5) change the load resistor value that is on MG1 (put another resistor in parallel with it). (6) then use the volt meter that is on MG2 to show that the power has changed. That is the Power Split Device is splitting the power different to what is was. By changing the load on MG1. Regenerative braking. You might like to tell everyone. That it is Lentz law that is in play so that they can also google it. Best Regards Roderick Wall.

[@WeberAuto]

Thank you and thanks for your feedback!

[@rodwall2335]

Hi John, do you think you will ever create the demo that I have suggested?

[@WeberAuto]

I would like to, but it will not be anytime soon. There are too many other video topics I am behind on and our Fall semester begins in one month here at the University. Busy season comes again. Have a great day

[@MbMax64]

Simply this is the best explanation of the regenerative braking which I've found. Many thanks.

[@euphrates9083]

Thanks, the video helped me to understand the topic thoroughly in terms of practical application. Greetings from Turkey.

[@joelfo9422]

Great job of teaching and explaining. Even for a semi-novice

[@WeberAuto]

Thank you!

[@ReaperKezia]

You are a true genius sir

[@WeberAuto]

Thank you

[@paulydublinboy]

Wow! It's astonishing how you make something so complicated to me a lot easier to understand. Thank you!

[@WeberAuto]

Thank you!

[@CeeOmega]

Nothing is like watching this when I just woke up. Great video!

[@WeberAuto]

Thank you!

[@dindoawitan6441]

Thanks sir John for another information that you’re sharing with us.

[@WeberAuto]

Thank you for watching

[@cMethoDx]

I'm no where near an engineer, or mechanic, but this is just so damn cool! Thank you so so so much for making these videos, keeping so up to date with this ongoing developing transport technology, and sharing this interesting knowledge and experience with the world ^_^

[@WeberAuto]

Thank you!

[@glenngoodale1709]

Wish I had a teacher like you, back in the day ......

[@WeberAuto]

Thank you very much!

[@iivaridark6850]

Yes, very educational! Nice to watch and I think very understandable for us not so educated ones! Regenerative braking is a wonderful way not to waste energy. And it's basically very simple.

[@WeberAuto]

Thank you! Yes, it is a great way to capture energy that would have been wasted.

[@voytek34ify]

jest pan doskonalym wykladowca,zycze zdrowia

[@berdia0305]

I do not know English, but I enjoy watching your program.)

[@WeberAuto]

Thank you

[@abelardoconesa9512]

Thank you for the detailed video. I am considering a new hybrid as my next car.

[@WeberAuto]

Thank you!

[@sharonbraselton3135]

Chief has BMW 2013 hybdei 328 ihybed BMW 2013 best car ece ded ram ybred

[@MoThomson]

Thanks for explaing the regen motors, you explain things so well John, very impressive

[@mortenlund1418]

It is fascinating to watch this. Everything from the awesome equipment to the fantastic cars. But best of all is your knowledge and the great way you pass it on. Thanks a lot.

[@WeberAuto]

Thank you very much!

[@rodwall2335]

Hi John, a great video on adding a electrical load while regenerative braking. Which causes the braking action. And changing the phase to reverse MG2 to reverse the car. What is also intresting is that when you added the resistance load to MG1 it made it harder for your drill to turn. In a real car. This would cause more of the ICE engine power to go through the power split device to the ring gear and to the wheels. And less power to MG1. This is how the load on MG1 determines how the ICE enging power is split. Roderick.

[@WeberAuto]

Thank you very much! You are correct. I wish I could have figured out a way to attach the drill motor to MG2 for the demonstration, but I would have had to remove the bearing on the shaft. I was too afraid I might accidentally damage it and not be able to get a replacement. This transaxle needs to work again :). Have a good day.

[@rodwall2335]

Thanks John, you indicated that you wish that you could have connected the drill to MG2. Can you please describe in words what this would have shown. B.T.W. your demonstration also shows. That when MG1 is spinning freely in some driving conditions. That no energy is transferred from MG1 because the inverter for MG1 doesn't put a load onto MG1. Thus MG1 is allowed to spin freely.

[@WeberAuto]

Connecting the drill motor to MG2 would have shown the same things. It would have been less confusing for some people since MG2 is the primary source of regenerative braking. I had some people confused as to why I used MG1. It was just for convenience while I talked about regenerative braking in general. Yes, MG1 can spin freely at times (like 0-35 mph (0-56 km/h) while MG2 propels the vehicle alone). I hope that helps.

[@rodwall2335]

Thanks John as to why you used MG1 and not MG2. Can you explain why MG1 only spins freely at speeds 0 - 56kmh. I thought it would be able to spin freely at a much higher speed. What about this to demonstrate the power split device. Connect your drill to the planet carrier (instead of the ICE engine). Put a resistor load onto MG2 to simulate energy to give the car kinetic energy or gravity energy going up a hill. Then switch in different load resistors on MG1. To show how power splitting is controlled by the load on MG1.

[@franksoliday5510]

Neat stuff is right! Brake pads must last forever with this system. You make the complicated understandable. Great series of videos on the Hybrids/EVs.

[@WeberAuto]

Thank you! Yes, the brake pads last a very long time.

[@joebell6283]

Great job Professor Kelly. My only negative comment is that Pico Automotive would probably not appreciate Fluke getting the credit for the 4425 scope.

[@jburdman7]

I agree with other poster. The L shift selection seems to employ engine breaking, where other modes can stay in Regen. Also, Regen seems to start as soon as one takes their foot off of the accelerator. This video explains a lot but leaves me with a few curiosities: Is Regen, as the dash display implies, much more efficient when barely employed? Does Regen hit the components hard until they heat up, then back off? I think I read somewhere that a Gen1 Honda Insight regen charges at around 60A till component heat forces a cutting back. This would preserve the most energy in cases where the brakes only get a quick stab, and shouldn't harm the over all efficiency in situations where a quick stab is followed by a long downhill grade. If you'd short the stator during simulated engine breaking, what would the current Spike to? Would rotor stop immediately? Any imbalance might crush the bearing. Maybe the frame which holds the windings would snap. If I get a ruined transaxle I'd love to speed up a MG and short the windings to see the result. Perhaps a wire would merely melt open. I'd like to see your generator-feeding-motor experiment redone with two windings attached as shown but take the third on the motor and short it while reading the current. You missed an opportunity to discuss the IR of the stator when computing the estimated 250W dissipation of the ceramic resistor. I'd recommend that you throw DMMs across the two and calculate the stator's heat dissipation. I wouldn't use a ceramic resistor for the smoke experiment unless you are coating it with something non conductive for your smoke emission. I'd use a carbon resistor with an inline fuse. A carbon resistor will heat up, catch fire, then if the voltage is high enough it's likely to align the carbon to a lower resistance, then blow that open. Tons of fun for a few pennies. It would be interesting to know the most limiting factor in the electrical part of the system. I assume regen is the most taxing and I'll guess it's the battery that's the weak link, but it could be the buck converter or the rectifier diodes. Very interesting video. Thanks for the brain candy.

[@WeberAuto]

Thanks for your feedback

[@erikwilson9498]

So amazing how much I learn from theses videos and I'm a mechanic !

[@ihatesmartphones]

Regenerative braking on a hybrid is the same as dynamic breaking in Diesel electric Locomotives, Just with the exception of not having a battery bank as a load. its a bunch of resistors. GE has made a locomotive with a battery bank tho. I wonder if the hybrid manufacturers got a lot of there ideas from diesel electric locomotives. They have been working on the same principles ever since they were first produced. Just on a much larger scale. I Love watching your videos.

[@WeberAuto]

Yes, same principle. Thanks for your feedback!

[@GavinM161]

Love the demonstration with the resistor.

[@robinwells8879]

Wonderful demonstration made with some very elegant demonstration pieces that bring great clarity. Lucky students. 👍

[@WeberAuto]

Thank you very much

[@dojohansen123]

Excellent video! Thank you very much. One minor detail: the amp-meter is of course DC (it is incorrectly stated to be AC in the video) , and since the induced current is AC we get the needle dancing around between negative and positive current (very fast, already at less than 1000 RPM you got 60 Hz according to the digital scope, which is much too fast for the human eye and your video recording equipment!) like a metronome on speed. :)

[@WeberAuto]

Thank you and thanks for your feedback!

[@HandyDan]

23:34 "Without endangering ourselves, which is a pretty cool thing" Haha best line ever John!

[@WeberAuto]

Lol. Thanks for watching

[@Enzo8mmSA]

50 videos later, I finally get it! Thank you sir!!!

[@rizaldecarulla8192]

Thank you Prof. Kelly, I learn a lot by visually integrating the lectures. GOD Bless Sir.

[@AlainHubert]

Indeed, good demonstration of the impressive efficiency of those motors. The same type of electrical braking is used in power tools to stop their rotation quickly to help prevent injury. BTW, I wish that all the teachers in my youth would have been as interesting as you to watch and listen to. Thank you for your dedication and passion towards sharing and transmitting (pun intended) your vast knowledge, professor.

[@WeberAuto]

Thank you! very much!

[@MrAntonioxi]

Toyota hybrid B mode not add more regenerative braking.. only engine brake like normal car, only needed long downhill when hybrid battery is full (84%) and not longer slow car, then you apply B mode.. All most every car journalist and sales people. Tells you wrong information.. New gen4 hybrid, test drive ch-r one weekend 😙 apply (ice) engine brake when drive cruise control and speed go up downhill. It's very interesting.. Mitsubishi outlander phev B mode add more regenerative brake and Nissan leaf.. Great videos 😊

[@dukesim6088]

You are right and Mr. Kelly got it wrong here. What he also got wrong: In the current Prius models regenerative braking starts with letting off the accelerator pedal. Depending on the velocity you get 3 to 10kW of regenerative breaking without touching anything. For actually free spinning you have to go into neutral (or slightly push the accelerator pedal).

[@Bigman74066]

I believe that the B position actually limits regen braking to prevent the battery from overcharging. Instead the MG1 and MG2 work together to increase the ICE rpm in order to slow the vehicle down. But I could be wrong.

[@dare4345]

Thanks for the demonstration! I was looking everywhere for the technical side regarding regenerative braking and you delivered just that. I appreciate it!

[@joechavez2643]

I would absolutely love to see a in depth explanation of the Gen 2 volts transmission system! Your content is awesome!

[@gambart2002]

Freaking amazing, I've been searching the KZbin for trying to understand this, and nobody could tell, that they use resistors to brake. 😉

[@rasikaranatunge9323]

Thanks a million Professor John for taking the trouble to do the regenerative braking video. As usual excellent stuff. I know my question is beyond the scope of your video. however I was always curios to know how the charging level increased from regenerative braking based on vehicle speed and the brake pedal pressure. As explained in the video it is by modulating the resistance between the MG and the battery pack, And its done through the inverter electronically. But the method its done is what puzzles me. Maybe you can give a brief explanation how the electronic part works later. Thanks once again for taking the trouble to impart knowledge to millions of people like us around the world

[@WeberAuto]

Thank you! it is called negative torque. Without the inverter providing an opposing voltage (through the drive IGBTs) to the voltage induced in the MG stators during deceleration, the charge rate would be at a maximum (The path to the battery would be MG to diode rectifier bridge to boost reactor coil (if equipped) to the battery). The opposing voltage provided by the inverter can: 1. Cancel out the voltage induced on the MG stator (no battery charging). 2. Not oppose it at all (maximum battery charging). 3. Provide a variable voltage to partially oppose the voltage induced on the MG stator (acting like a variable resistance providing a variable battery charge rate). I plan on making a video on inverter operation soon. I hope that helps. Best wishes.

[@rasikaranatunge9323]

Thanks a lot for the explanation and quick response. That answers my question. Hope to see some grate videos from you in the future. As an owner of a Prius Gen 3 car, Your videos have made me enjoy and drive the car better. Wish you all the very best.

[@joemasterman4305]

Wow! Very cool using the output of one motor to power the other, kind of like testing both rotors and stators. Blew my mind!

[@WeberAuto]

Thank you!

[@rajesheeeram3808]

Great video. Very useful for understanding regenerative braking effectively. Thank you sir 👍

[@solarpall]

Very nice demonstration professor. Thank you for what you are doing here.

[@WeberAuto]

Thank you!

[@dshenmdyn]

Thank you for another great video of demonstration. Learning this way is fun!

[@WeberAuto]

Thank you very much!

[@HaykshadPavel]

what a fantastic video! I am really shocked with such a clear explanation. Bravo prof. Kelly!!! Your videos seem to me a huge treasure that is gifted by you for free. It's unbelievable. Thank you, Sir.

[@TurbineResearch]

This is the best explanation of electric motors I have come across. Thank you sir !

[@anaudiophile]

As an auto tech, I've been in many training classes over the years (decades actually) and have had good and not so good teaching. Your way of simplifying the material is very good! Your demonstrations are excellent also. Practical demonstrations are often the best way to help understand the topic. In this video I was wondering, if by chance the imbalance of the drill adapter could be the reason behind the jagged AC curves and the peaks/valleys ? It's an interesting curve profile for sure. And I'm glad you were able to return to work after your accident! You obviously have a passion for teaching!

[@z06doc86]

Another video with excellent explanations of somewhat complicated material. 👍👍

[@roelofviljoen6350]

Hi Prof Kelly, correction at 3:45, it is a DC ammeter

[@WeberAuto]

Thank you, you are correct

[@Smookg]

I have 2nd Gen, in"B" realy use both braking motors. But it is not necessary because the batteries are only able to hold up to 100A of charge, which means that even one electric motor is able to generate more power than the battery can. Therefore, there is no increase in efficiency when using "B", on the contrary, the vehicle is also slowed down by a petrol engine that saves no energy (only generates heat).

[@WeberAuto]

Thanks for your feedback

[@Horsecockbadger]

What an amzing professor.

[@dorydaw8281]

thank you for all the effort you put to produce such an amazing learning experience

[@ShiTingHuang]

Thank you! Even my English is not good,I can understand professor’s teaching.

[@jamesfarnham1976]

Excellent stuff!! TY Professor.

[@WeberAuto]

Thank you!

[@97ynoT91]

I LOVE the thoroughness of your videos... Thank you for sharing your knowledge. You do so brilliantly.

[@lifeupnorth9385]

This is one of the best videos on this channel, pure awesomeness!

[@WeberAuto]

Thank you

[@martinsandage1915]

WeberAuto please message me

[@maureenwangui5348]

thanks for your videos prof I've learnt alot about the hybrid transmission from you Ones from Kenya.

[@hpmoxie4660]

Prof is simply the best!

[@peppeddu]

Fascinating video. Now the question I have is: On a long long downhill (say 5 miles), do you get better mileage by slightly pressing the gas petal just to stop the regenerative braking or do you get better mileage by leaving your foot off the petal altogether? My reasoning is that it's always better to keep kinetic energy rather than charging the battery and then back to kinetic.

[@WeberAuto]

regenerative braking can add power to a battery if it has room for the charge, otherwise the energy is wasted by spinning the engine crankshaft.

[@peppeddu]

@@WeberAuto Thanks!

[@sharonbraselton3135]

Regen adds reag downmil regern add 5 mies more

[@TheDisgruntledMechanic]

Got a kick out of the smoke show! Very good information. I am waiting for the next Volt videos! I want to learn all I can about them.

[@WeberAuto]

Thank you!

[@mushenji]

Correction. That Ammeter you used is a D.C Ammeter not A.C. An A.C Ammeter would move in one direction only.

[@WeberAuto]

Yes, thank you.

[@nick8116]

Finely got the answer how “B” work. Thanks!

[@shamanthjilla]

I wish I had such professors in my engineering undergrad

[@WeberAuto]

Thanks for watching

[@thisisTrev]

Best explanation on the internet. I love this whole channel from the eCVTs to the differential videos. But I still have questions about this. When it's coasting, I am charging the battery, but not as much, correct? So then when I press the break pedal, It opens the circuit up to the battery? Or, it was always open to the battery, but now we've added resistanc? Is the battery resistance by itself? I get how adding resistance causes the motor to slow down more. I don't get how adding resistance makes the stator produce more voltage or charge the battery more. And when you talked about negative torque. Again, I get how that slows the car. But now it seems like we're putting battery voltage back into the stator, that must lessen the charge we get from the breaking? How much less are we charging in free spin mode vrs breaking mode? I'm in a 2016 rav4 hybrid.

[@WeberAuto]

Thank you. The connection to the battery is never open during deceleration, the inverter uses battery power to create an opposing voltage to the voltage being induced by the spinning rotors. Think of what happens if you put two AA batteries in a flashlight, or other device with one facing the wrong direction. The two opposing voltages cancel out each other and no current flows. Thanks for watching

[@thisisTrev]

@@WeberAuto I can easily imagine how the m/g can be used for deceleration. It's also easy for me to imagine how the motor is used as a generator. My confusion is, how is the increased deceleration used to charge the battery at a faster rate than normal coasting? When I take the foot off the accelerator, the power from the wheels turns the generators. But when I press the break, the needle dips further down into the "charge" zone. That's the part I can't understand.

[@WeberAuto]

@@thisisTrev It is accomplished the same way, but by changing the level of the opposing voltage during deceleration versus applying the brake pedal.

[@drajitshekher]

As I understood it, applying a light b braking via the pedal only uses 1 motor for regeneration, while when putting the transmission in B mode it uses 2 motors for regeneration. Why can the system not use both motors for regeneration with moderate breaking via the pedal?

[@buixote]

Looks like we need a resistor in series with that poor ammeter! ;-) Great Video!

[@amitzampa315]

Very Nice , Excellent Quality of lectures and practical

[@PaintSlinger99]

I hope Weber knows what an asset they have. Very interesting, Thanks.

[@cheese.n.crackers]

Your videos are outstanding! Thank you!

[@WeberAuto]

Thank you very much

[@sagster]

I've only recently come across your channel Professor John and I must say I absolutely love the way you explain things with practical examples and demonstrations. I'll be watching a fair few of your videos from now on I think :-) Awesome stuff.

[@WeberAuto]

Thank you very much!

[@Jthumper]

+1 on this, he is awesome!

[@tarassu]

17:25 - in case of emergency braking regenerative load is removed for optimal ABS functionality. Usually this requires slamming brake pedal fast.

[@tarassu]

This definitely applies to EV's. Not sure does it happen with all hybrids as there is not a lot of regen happening.

[@WeberAuto]

It applies to hybrids as well. Thanks for your feedback

[@javierc.salazar512]

What a great video, thank you so much Prof. Kelly. Take care and stay safe.

[@WeberAuto]

Thank you very much