How the Accord Hybrid system works
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- เผยแพร่เมื่อ 13 มิ.ย. 2014
- Lately I have had a number of emails asking about Consumer Report's review on the 2014 Honda Accord Hybrid. In their latest review Consumer Reports and the Wall Street Journal complained that the engine starts and stops randomly and revs without regard to accelerator pedal position or speed. What gives? The answer, and in my mind the key to living with the Accord Hybrid, is in knowing how the hybrid system works. You see the Accord uses a very different hybrid system than the Prius, Camry Hybrid, Fusion Hybrid or even the Volt. The Accord is a true serial hybrid below 45 MPH. While the operation of the system is distinctly different from the parallel systems on the market, the real world fuel economy of 40-50 MPG (depending on conditions) more than makes up for things in my book. The important thing to remember is that this hybrid behaves differently than other hybrids on the market. While I think that's a good thing, I'll let you be the judge for yourself.
Accord Hybrid Explained
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Wow Great job explaining this. I have read many articles and sat in many training classes on this new amazing Honda Accord. Nobody has explained it as well as you.
What a great explanation! Thank you. I am considering the 2018 Accord hybrid and this video is perfect. Your reviews helped me buy a 2016 Sonata PHEV and a 2017 Volvo S90 too. I hope it is worth your time to review the 2018 Accord Hybrid.
Great Job Explaining the Accord Hybrid System , maybe Consumer Reports needs you to review the Car ! Hard to give a review unless you really understand what your talking about , not just a feeling or guess !
Excellent explanation!!!, This is also the way that the new Clarity PHEV works. thanks!!
Finally...you have cleared it all up for me. terrific, Alex. Thanks
Great explanation. Thanks Alex.
Wonderful explanation!
Good explanation Alex, hopefully the word will spread. I don't see this as a Prius competitor directly simply because it's larger, upscale and more expensive. But to those comparing hybrids the comparisons will certainly come out. What's unique to the Accord is that there isn't a transmission in the traditional sense at all. Torque supplied to the front wheels is regulated by the electric motor, the engine being a generator through separate windings to the battery and traction motor. It is that design which provides a seamless flow of torque.
After one year of ownership my only true wish is that more battery only power was available at partial charge before the engine kicks in to add more current and charge. If you are very light on the throttle you can maintain electric mode only at partial charge but not if any acceleration is needed. Just a tad more "oomph" from the battery pack under such conditions might do it? When near or fully charged it acts much like I'd like it to all the time. Maybe some software tweaks will enhance this in the future? Can't complain about the results however, even climbing up to 500' where we live around Seattle I average 44 mpg on a tank and that's dipping into its torque rich power (just a time or two!) :)
Very informative, good job!
Brilliant work cowboy!
Excellent Alex!
Hi Alex. Hope to see you review the 2015 Honda Fit sometime. It should be a great little car and the best entry in subcompact segment. I'm buying a hatchback by the end of this year and it's between 2015 Fit and 2014 Mazda3. Decisions, decisions...
Great video!
Thanks Alex. Your videos are always top notch. I own a 2014 Honda Accord Hybrid EXL. I purchased it new in January 2014. Paid top dollar because it was a “hot” model at that time and drove about a hundred miles to an out of state dealer. But I’m still glad I did. Just had it clay barred and it looks great & drives fine. I average about 40 MPG about town with my heavy foot. Have only about 75,000 miles on it with just routine oil changes. I usually change oil at 60% use. I do my air filters myself. Tires rotated. (Have put new set on about two years ago.)
My one question is - what is this engine number or engine designation? Can’t find that info anywhere. After searching, it could be a K24…..? Something or other? Thanks & keep up the great work. Rich C.
hi, I have accord 2014 touring and have a question on auto climate control. when I on auto Cc I see the blower speed goes down. keeping AC on I can blow at full speed. which should be preferable way of cooling keeping best possible MPG...thanks in advance
The acceleration in this car is great. Instant torque. Getting 55Mpg in mine.
Very informative and nicely done. The Honda system is a generation ahead, but people don't expect it to behave the way that it does, and the sales organization are not doing the very best job explaining it well. They should just use your video in the showroom. :-)
From my experience at the dealerships I have been to the salesmen suggest not buying the hybrid...it truly is bizarre. On the other hand it explains the lack of movement that these cars have locally. The Volt is outselling them here by quite a margin.
Thanks again Alex. I always had assumed Honda went the same route as Toyota & Ford with their Power Split Hybrid when they mentioned a 2 motor-generator setup.
However doesn't this mostly serial hybrid system be less efficient than that of the Voltec/Synergy Drive mostly parallel hybrid design?
How many years does the Honda Accord battery last? And how much does it cost to replace it?
Does this information apply to every year model, 2005 specifically?
The 2005 honda accord hybrid is a good car??
How often do you replace the clutch pack in these hybrid Honda accords? I'm looking at maintenance costs between the Toyota hybrid system and this Honda system
Did you ever find your answer? I am stuck between those 2 hybrids at the moment
Drove the Accord Hybrid the other day (the Volt twice earlier) and could feel the gas engine engage the wheels at higher speed and it revving up while around town powering the electric motor when accelerating...none of it felt as "ghostly" or seamless as the Volt did while driving, but that is due to the massive battery capacity compared to the Accord. Just feels,like it use a little more capacity to smooth it all out a bit (not that it was necessarily harsh, but just doesn't provide that full EV experience that I am looking for). As to the rest of the car, the Accord is head and shoulders beyond the Volt, but what do you expect when it is based on a $25,000 middle sized car and the Volt is based on the more compact Cruze that starts at $17,000. Thus my dilemma...
some times when driving into traffic and want to increase the speed of my 2015 Honda accord hybrid the sound of the gas engine goes very high and the speed still low what do you think is the reason for that?
I think it's the battery level. Have you down shifted to B? My 2014 does the same thing to me
Alex, so now that Honda lowered their EPA rating on the Accord hybrid, as CR had suggested, any new updates on your end?
Honda hasn't lowered their rating. That was Ford as they admitted to making testing errors (and EPA was already investigating that for long time).
CR is misleading everyone by saying all Hybrid EPA numbers should be corrected including Honda Accord Hybrid. Their test results was higher than the Ford (with same previous 47 mpg rating) and at same time below what people actually report.
In the end ymmv is more true with hybrids since amount of regen has huge impact and that depends on your route and driving style. I think their city test is not typical. Best to just to do long test drive to gauge mpg you might get.
Fantastic Explanation
This should be Honda's message about this technology in a nutshell.
Nice informational video Alex. Do you happen to know approximate engine RPMs are if the clutch engages at 44mph and up? Based on this, is it safe to assume that MPG will go down faster since engine will have linear relationship with speed? What speeds would you have to go to meet the EPA's rated MPG on this Accord Hybrid (45 MPG highway)?
***** I don't recall the RPMs but the best fuel economy is in the 55-60 MPH range.
+Nigel Yu ON the highway the hybrid acts like a normal Accord in 6th gear. Same RPM/speed relationship
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The Chevy Volt operates in either EV or serial mode. The gas engine is a generator only and is NOT connected to the drive train. The Accord Hybrid runs EV very briefly, then Serial Hybrid up to 43 MPH, then switches to the gas engine by engaging the clutch. Unlike other hybrids like the Ford Fusion Hybrid, which transition to and from the engine seamlessly, you can definitely feel when the gas engine grabs the wheels in the Accord Hybrid.
Larry Milligan GM initially told everyone that initially, however the hybrid system in the Volt is based around a planetary power splitting gearset like the Prius with the exception that the input/outputs are re-arranged and the added a clutch. The system will indeed operate in parallel hybrid mode as well and the very design was created with this in mind. (Otherwise there would be no need to use a planetary powersplit set). GM says that the reason they do this is that it improves fuel economy by 15% when the battery is depleted. There is plenty of info on this online, GM issued a press release to this effect on October 10, 2010
Larry Milligan I should add that the transmission will select what mode works best, but in general when the battery is depleted and speeds are over 70, the system is almost always in parallel mode. Motortrend had a few interesting pieces on it with interviews from GM engineers also in October of 2010.
Alex on Autos We're sort of arguing some very fine points. The planetary grearset connects both electric motors, not the engine directly, and torque from the engine can be applied to the 2nd electric motor so that indirectly the gas engine can contribute some amount of torque to driving the wheels. You are certainly right with that. However, depending on how you drive, you may well never see it happen. You have to be driving on a depleted battery and exceeding the speed limit (in this State anyway). In my personal experience over the past 3 years driving my Volt, when I hop on the Interstate, I put it in "Hold" mode and in that mode, even at speeds above 70 mph, the gas engine is still only operating as a generator and the car actually switches back and forth between EV and Generator mode (in my experience anyway). I suppose someone who drives fast on a depleted battery would experience the parallel hybrid mode in those cases. It has only happened to me a couple of times in 3 years. You can usually tell by the engine rpms. Anyway, thanks for your very prompt response, and for your very detailed and accurate videos.
Larry Milligan It does depend on driving cycle, but unfortunately there is really no way without scanning equipment to know what is happening. According to GM however if you're driving 70 MPH or higher you will almost certainly be in parallel hybrid mode. The reason is that GM is after the best fuel economy and parallel hybrid mode is almost always going to be more efficient than serial mode (according to GM, Honda and Toyota). The issue is the power conversion from generation to step-up/step-down, possible charing and the requisite rectification and inversion. According to Toyota who is the only company to be very up front with percentages, the typical loss between MG1 and MG2 in their transaxle is about 20%, which is a decent loss. GM won't specify but they more or less admit that their loss isn't too far off those figures. This is why parallel mode exists. In this mode some 70-80% of power is sent mechanically from the engine to the wheels and the remaining 20-30% or so takes the electrical path across and suffers from loss in that 20%ish range. That makes the overall loss much smaller since the mechanical loss is relatively insignificant. According to the OnStar and other data on Volt owners, most owners drive about 8,000 mines in EV mode and somewhere around 7,500 miles in gas mode. (Note that Volt specific sites can skew these higher, so we have to go by the occasional GM press releases) Since the average speeds on US highways is 72MPH, we can safely assume that the average Volt owner sees parallel hybrid mode frequently on the highway. In honesty I think that GM did everyone a disservice by the way they chose to describe the system initially and then they came back and filled on far more detail that in many ways contradicted what they had said. GM basically mirrored what Toyota had said before that you basically don't really want a serial hybrid in most situations if you can avoid it, especially at highway speeds. Now the key to the Volt's design still is that serial mode, because it is required to give the torque required to hill climb and the reason that even at more moderate speeds you can encounter the mode switch. With a GM data logger on a test car, the Volt tester that GM lent me was essentially in parallel mode at most speeeds over 50MPH or so unless you needed more torque when the system would switch to serial mode so that it could generate power and essentially trade HP for torque (in a round about sort of way), that power augmented with the battery will give you the optimum hill climbing performance. The other interesting twist is that in the 0-60 and 1/4 mile tests, the Volt switches to parallel hybrid mode in the test run and gives a better 0-60 time than if you're in EV mode alone. The differences with the Prius are important, but in most key ways the Volt can be seen as a variant of the same design with very different software. Neither car will move without the motors involved, the Prius cannot move without MG1 and MG2 working together to manage the power flow, but it can never truly operate in a real serial mode like the Volt can.
+Larry Milligan QUOTE: "The gas engine is a generator only and is NOT connected to the drive train." FALSE. One of the electrics motors is tied to the wheels & after the EV battery is depleted, the engine connects itself to that motor/drive train
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So you would end up using more fuel anyway when the engine revs so high...
basically the honda accord hybrid is the same as a koeinsegg regera.
I know many people are wondering how consumer reports got 32 mpg city in this, the Camry hybrid xle and prius IV....all I can come up with is the way their city loops are run...the city loops test the cars assuming everyone is a lead foot which does not accurately provide comparable numbers for hybrids as they all have different hybrid systems
Exactly my thought. They got 49 mpg on highway but that's more predictable test since it's a fixed speed and Accord will alternate between ICE and EV mode.
I think their city test probably doesn't allow much for regen. Or they hit the brake pedal too hard and lose some of the regen.
Lucien E Yeah they got 47, but I think it also has to do with the different trim levels they test...if they tested the base prius or the base accord hybrid I'm pretty sure they would've gotten higher results due to their lower weights
+44,537,955 views (1) The city test by the EPA is the unrealistic test. It's supposed to be a mimic of Downtown LA but my driving in LA gets nowhere near the 50 advertised for Prius or Prius C. (2) My city score is closer to what CR scored in their tests, and so I think CR's test is more accurate to real world drivers
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electrictroy2010 For me it's different. I always beat easily CR city test. It's highly dependent on amount of (light long) braking and how much acceleration you need to get going again (e.g. slow acceleration to lower speeds will get you to EPA). Their 32 mpg city seems atypical. No perfect test I guess exists...
I hope that the 2017 Accord Hybrid has a Lithium Ion battery instead of a Nickel Hydride. The LI seems to last the whole life of the vehicle while the NH dies in the middle of he car's life and costs too much to replace.
I thought Chevy Volt is working like the Accord?
The Volt's design is actually more closely related to the Ford/Toyota hybrid designs. It uses a planetary gearset power split device with two motor/generator units. The difference is that GM uses more powerful motor/generator units, a battery that can put out the full power requirement of the motor (rather than about 25% as in the Toyota hybrids or 35% as in the Ford hybrids and GM adds a clutch to the transmission. The clutch is used improve efficiency when in EV mode and to allow the system to operate in serial hybrid mode (the Toyota and Ford units lack a true serial hybrid mode). The GM system allows the car to select whatever mode is most efficient at the time (assuming it is not in EV mode). Higher speeds and higher power requirements will cause the Volt to switch to parallel mode, low speeds will cause serial mode where the engine can more efficiently cycle on/off to maintain the battery. Now, like the Ford/Toyota unit, the Volt's engine cannot power the wheels without the motor/generators involved. The Accord when in lock up mode can bypass the motor/generator units and power the car directly through that fixed gear ratio.
Ford and Toyota use a planetary gearset and two motor/generators to make an electro-mechanical power split device. This is a great explanation of the Toyota/Ford system eahart.com/prius/psd/
+David C Schlesinger HONDA's IMA inserts an electric motor between the engine & the manual or belt-drive transmission. It sits where the flywheel used to be. It's a very simple design compared to the Ford/Toyota system with two motors & automatic transmission
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All that Honda needs to do is muffle the engine to the point the driver no longer experiences cognitive dissonance between engine revolutions and speed.
muffling the noise adds weight and cost
mountainhobo It's pretty subdued as it is. In-town driving will at times bring out the disconnected engine feeling but for the most part it just goes about its business. (We have the Touring model)
+John Wayne NOT really. The Accord V6 uses the speakers to "noise cancel" its engine noise, especially when running in vibrating 3-cylinder mode. Honda could use the same tech in the hybrid
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+electrictroy2010 They do! At least in our Touring trim 2014 they do. Pretty subdued inside except for increased tire noise on worn pavement.
Very interesting. My feeling is that for all practical purposes, the Honda and Volt use the same basic system. But I betcha dollars to doughnuts that any buyer considering a Honda hybrid would poo poo the GM unit because, after all, it's GM and all American cars are bad. Conversely, I suspect that many Volt owners think of Accords as 'furin' junk, even though they are made in Ohio.
But the real truth is that GM spent a buttload of money developing the Volt, and Honda benefits greatly by copying GMs design. Where I give Honda props is it seems the Accord is a Volt clone, but WITHOUT the $10,000 battery or it's weight. Very clever.
The Volt will go down in history as a noble failure. In 2008, gas shot up to $4. By the middle of 2009 it was down to $1.60. Had gas prices not done that and instead went to $6, we'd ALL be driving Volts or other series hybrids. The plug in, series hybrid is really the best all around system.
They not similar at all. The volt appears to have a transmission where the balance of power and gear ratio is controlled via clutches and/or differences between motor outputs around a planetary gear set. It's really the next evolution of what Toyota started with the Prius and is a fairly complex system.
The Honda system is a much bigger jump. And far more elegant then what GM and Toyota have come up with. As far as I understand there is *no transmission*.. none. There is a generator driven by gas motor an electric motor driving the wheels. And a clutch pack that can clutch in the gas motor for steady state cruising at a fixed ratio.
The Honda system is beautiful and elegant in it's simplicity.
Here is how it works.
Below 72 km/h. The gas motor spins the generator which gives power to electric motor to drive the front wheels and at the same time charge the battery if needed. There is where a bit of confusion will appear in drivers. Since the motor is spinning a generator only the gas motor RPM can vary while speed remains constant. For example if the car decides to top up the battery the motor RPM can rise a bit to have enough power to drive the car and top up the battery even though you're maintaining a constant speed. So here your motive power is ONLY electric the power can come from whats stored in the battery or from the generator.
Above 72km/h: There is a clutch pack that can connect the gas motor directly to the wheels. There is a fixed ratio there is no gear mechanism that can change it. So your motor is *directly* connected to the wheels. This is the most efficient mode for cruising at those speeds because it's the most direct path for power. The less 'things' in the way the more efficient a system becomes. At this fixed ratio the gas motor will not be able to accelerate the car by itself so the required torque to accelerate comes from whats stored in the battery. The 'torque fill' is done by electric motor. So it will actually accelerate the car and the RPM of the GAS motor with the energy stored in the battery. However what if you need a LOT of power. Here is where the interesting part happens. To get a lot of power you need to spin the gas motor at high RPM so the system will declutch the gas motor from the tires raise the RPM of the electric motor sky high to produce the required power by the generator and give you torque you need.
It's a beautiful system comparing to the complex monstrosities Toyota and GM engineered for their hybrid. This system completely eliminates the parasitic drag caused by a transmission on the order for 10-20%.
+Kip Amore QUOTE: Honda benefits greatly by copying GMs design." What an idiotic statement. The Volt has a complicated transmission and the Honda doesn't (just a direct drive), so there's no copying of any kind. Please don't accuse people of plagiarizing when that never occurred. Honda's design is more similar to its original 1999 IMA system than the Volt design
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