Yaris Plugin?

[Mike J.]

I was thinking of what Toyota could do as a future enhancement to the Yaris rather than it being a DIY job.

[Anthony Poli]

7 hours ago, Mike J. said:

I have just been doing some maths and using Hybrid Assistant to work out what is happening in the Yaris.

 

The Yaris has 20 NIMH packs, each pack is 7.2V 6.5Ah. Thus we have 144V (20 x 7.2) in the 0.936kWh pack (6.5 x 144). If this was all available, the Yaris could easily do 5 miles at 30 mph in EV mode - but it doesn't (as mentioned by Toyota in the manual)!

Using the Hybrid Assistant battery check it shows that the targeted maximum charge seems to be 60% full and the lowest charge allowed is 40%. Thus only 1/5th of 0.936kWh is available in EV mode - giving around 1 mile at 30mph.

BTW, my battery test showed only 6.2Ah and not 6.5 - what is yours .... ?

What is interesting is that you could probably fit a 2kWh Lithium Ion battery in the same place as the NIMH (approx twice the energy density). This should give around 10 miles of gentle EV driving. With the ability to home charge (from empty to full in an hour!) we could also get pre-conditioning for those winter mornings - the only real bonus of a full EV (Renault Zoe) over the Yaris.

I have only done the test once, it was 5.65Ah. Going from 166V, down to 143V.

Not tried the Auris to see how it compares.

 

[Anthony Poli]

18 minutes ago, Mike J. said:

I was thinking of what Toyota could do as a future enhancement to the Yaris rather than it being a DIY job.

The latest technology from the Prius will filter down to the Yaris, which should reduce weight, increase efficiency of the ICE and electric motors. 

[dickins]

The best tweak to Yaris Hybrid would be to enable slightly higher reliable speed with Battery only - say, a true 30mph. 

[Anthony Poli]

8 minutes ago, dickins said:

The best tweak to Yaris Hybrid would be to enable slightly higher reliable speed with battery only - say, a true 30mph. 

Have seen a youtube video showing a software mod, where a gen 1 or 2 Prius doing 70Mph in EV. The technique used was to drive both electric motors, having said that, Toyota could change gear ratio's to allow a higher speed in EV. 

Toyota probably have had to trade off between economy and manufacturing costs.

The software change would be the simplest method, run the second motor when the car gets to 30Mph.

 

 

[Peter S]

If a 45 Kw motor can't propel the car any faster than 30 then there is something wrong with it, or it's being greatly restricted by the software. 45 Kw is 60 BHP, a dam site more than most older petrol engines. In fact the ICE in the Yaris is only 54 Kw and that gives it a top speed of over 80 mph.

[Mike J.]

2 hours ago, Peter S said:

If a 45 Kw motor can't propel the car any faster than 30 then there is something wrong with it, or it's being greatly restricted by the software. 45 Kw is 60 BHP, a dam site more than most older petrol engines.

It can. The maximum speed the Yaris can attain in electric mode varies in 2 ways: if you have forced EV Mode, then you can use more 'power' on the ECO scale but the max. speed is about 31 mph. If you are not in EV Mode, but gently accelerate in electric mode, you can get to around 42mph on a flat road. The latter speed is purely dictated by the epicyclic gearbox design and the former is probably due to Toyota wanting to protect the inverter electronics and the Battery pack to give 10 year fault free service. Note again that it seems that the Yaris Battery state of charge (SOC) seems to be kept between 40% and 60% - very conservative.

The electric motor has 169Nm and if it was compared to the BMW i3 that has 260Nm torque, like for like the max. power (at 6000rpm) for the Yaris would be around 100kW! So, again Toyota are protecting the system with software.

I would like Toyota to sell a performance upgrade (software only!) to allow Battery use of 20% to 80% SOC with more power available - probably get 3 miles on electric mode at 40 mph. It could also allow more power to reach the electric motor, for longer - at the moment it gives 169Nm for only a few seconds when at full throttle. If it gave the full torque for 6 seconds, then 0-60mph would come up at under 8 seconds. I would pay a few hundred pounds for it.

Any further enhancements should be in the next generation - 2kWh Lithium Ion (small enough to go under the rear seat) with home charging, pre-conditioning, 4WD option, heated steering wheel, 0-60mph in 7 seconds. Anything else?

[Anthony Poli]

It's motor 1 that limits the speed of motor 2. Some where over 15000 rpm, the ice has to run in order to protect motor 1.

The gear ratio is the problem, the latest Prius is built differently to overcome this problem.

 

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[Anthony Poli]

49 minutes ago, Anthony Poli said:

It's motor 1 that limits the speed of motor 2. Some where over 15000 rpm, the ice has to run in order to protect motor 1.

The gear ratio is the problem, the latest Prius is built differently to overcome this problem.

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Motor 1 (mg1) is the generator and starter motor.

Motor 2 (mg2) is the EV motor.

There are some informative YouTube videos on the evolution of Toyota's hybrid drive train and how it works, plus drawbacks.

 

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[Mike J.]

4 hours ago, Anthony Poli said:

It's motor 1 that limits the speed of motor 2. Some where over 15000 rpm, the ice has to run in order to protect motor 1.

Not true for the Yaris, it is a further generation (3rd) from the Auris in that it has a 'Motor Speed Reduction Device' and is also chainless. In the Yaris, the speed of MG1 is almost the same as MG2, but in reverse direction (in electric mode) - check out the info from Torque pro. Given this, the 42mph limit might be to protect the connection between the electric motors from high revs?

[Mike J.]

I have just noticed in some Yaris blurb on the inverter stuff, that "compared to the Auris Hybrid, unit output current has been reduced from 120 to 80 A and output voltage lowered from 650 to 520 V, saving system energy with no loss of performance or efficiency".

Well ... I think electric performance might be affected in that if you use P=IV, you can see why the Yaris only has around 42kW (not sure how 45kW is derived).

[Anthony Poli]

3 hours ago, Mike J. said:

Not true for the Yaris, it is a further generation (3rd) from the Auris in that it has a 'Motor Speed Reduction Device' and is also chainless. In the Yaris, the speed of MG1 is almost the same as MG2, but in reverse direction (in electric mode) - check out the info from Torque pro. Given this, the 42mph limit might be to protect the connection between the electric motors from high revs?

I will correct you on one point the Auris is 3rd generation, the Yaris needed modification in order to fit the hybrid system into the smaller body. To the extent that the engine bay is slightly larger to accommodate things. 

With driving both a 2010 Auris and a 2013 Yaris, I can compare both on the same journeys. Only real differences are, the acceleration is slower beyond the EV speed on the Yaris and the top speed is 10 miph less according to the Toyota manual. Even though the Yaris has a 45Kw motor, it will still accelerate faster on EV than the Auris and travel longer on EV.

I had a 2016 Yaris hybrid as a courtesy car while I had the Auris in for a recall, between the 2013 and the 2016 Yaris, it felt the same as for performance and feel.

 

 

 

 

[Mike J.]

41 minutes ago, Anthony Poli said:

I will correct you on one point the Auris is 3rd generation, the Yaris needed modification in order to fit the hybrid system into the smaller body. To the extent that the engine bay is slightly larger to accommodate things.

That would make sense. I was taking info from my Yaris pdf which compared it to the Auris and mentioned: "The transaxle now incorporates a multifunctional motor reduction gear within the power division mechanism, and a new gear deceleration mechanism abolishes the use of chains". This sort of hinted that the Auris was 2nd generation.

[Anthony Poli]

I hope I didn't cause any offence by my last post.

Obviously the technology will constantly improve. Maybe the information about drive train and mg1 I was going by was from a gen 2. I was just trying suggest why there were limits and what could be done to work round them with the existing models.

 

For the price of the Yaris, it certainly is hard to beat. For 30 litres, I have nearly got the same mileage, as 36 litres in the Auris.

 

Just a shame they didn't put in the joystick and kept the standard automatic style gear stick.

 

 

 

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[Peter S]

On 21/05/2017 at 4:16 PM, Anthony Poli said:

Hybrid assistant and hybrid reporter are apps for android devices, you also need a OBD link (wifi, bluetooth or usb). It will collect data from the car, that you can email or send it to your computer.

Just got one of these a TORQUE ELM 327 PRO from Amazon. Downloaded both apps and gave it a try with no luck the app connected to the device but no data was shown. also no way to select what car is displayed. What am I doing wrong?

[Anthony Poli]

2 hours ago, Peter S said:

Just got one of these a TORQUE ELM 327 PRO from Amazon. Downloaded both apps and gave it a try with no luck the app connected to the device but no data was shown. also no way to select what car is displayed. What am I doing wrong?

Did you connect the device to the car and press start, before you started the app?

[Anthony Poli]

Next tap on the spanner at the bottom right of the screen. Check to see if the appropriate tick is next to the type of device (BT, WIFI or usb).

 

[Anthony Poli]

Hybrid assistant and hybrid reporter are apps for android devices, you also need a OBD link (wifi, bluetooth or usb). It will collect data from the car, that you can email or send it to your computer.

Just got one of these a TORQUE ELM 327 PRO from Amazon. Downloaded both apps and gave it a try with no luck the app connected to the device but no data was shown. also no way to select what car is displayed. What am I doing wrong?

 

 

How are you getting on with the hybrid assistant?

 

 

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[Peter S]

Tried it with my wife's Android phone as I have an iPhone at the moment. It came up with a load of error messages and then on restart it doesn't play ball with the car. I'll give it another try when I get my own Android phone.

[Peter S]

OK so I now have my own android phone and the app still doesn't work with the bluetooth gizmo so I downloaded another app and was able to get data from the engine ECU on my Lexus and it works, I can see engine RPM etc. Hybrid assistant still wont report what car it is or show any data.

[Anthony Poli]

OK so I now have my own android phone and the app still doesn't work with the Bluetooth gizmo so I downloaded another app and was able to get data from the engine ECU on my Lexus and it works, I can see engine RPM etc. Hybrid assistant still wont report what car it is or show any data.

 

It's definitely ticked for bluetooth, in the settings when you tap on the spanner?

 

 

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[Peter S]

Yup, the spanner box is green and the one next to it on the left is also green but only displays 3 dots. The rest of the display is greyed out.

[Anthony Poli]

Hmm

I have had the three dots, but you should get Yaris showing.

 

 

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[Peter S]

Am I being too impatient, how long does it take to recognise the ECU etc or do you have to be moving as well as powered up?

[Anthony Poli]

It shouldn't take more than 30 seconds. Even if you haven't got the ready light on the dashboard, it will show you the auxiliary Battery voltage (12 volt).

 

 

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