Why I avoid series mode.

After doing my 6 monthly Ev range test and seeing I had a empty drive battery I thought I would like to see how the fuel economy is with the phev in series mode using the same loop I did for my EV range test.

To make it accurate I pressed the reset on the fuel computer when the petrol motor started and was charging the battery and drove the approx 20km loop and towards the end of the loop noted when the petrol motor restarted to again start charging the battery ie drive battery at its lowest in both cases in the 60km/hour speed zone after multiple charge, ev, charge, ev cycles etc.

Result was 6.7lt/100km .

I been trying to been trying to figure out how I can compare that to a parallel mode economy run but accelerating up to 70kph to engage parallel mode in a 60kph zone is just bad for your license around here with police.

Then I remembered this that I posted in Technical graphs and images.



Material from anko .

The 2nd graph down showing 15.32km/L at 92kph which works out at 6.53L/100km in parallel mode. Not much difference (for fuel) but a fair bit faster.

I still think I am doing the right thing charging up the drive battery out on the highway (parallel mode) and getting 0L/100km around towns and cities on trips away (as much as possible) from the grid charge and I think this endorses that. I can afford the extra fuel but why burn it if you can save it just by pressing a button every now and then? it all adds up.

Regard Trex.

It does add all up, doesn't it?

anko said:

It does add all up, doesn't it?

Click to expand...

I love making the phev run as efficient as possible.

The key here is parallel hybrid mode operation and then EV mode. The test was for only 9 or so km, and the battery could have been at empty, in NORMAL mode, or at full in CHARGE mode, or somewhere between in SAVE mode. How much of the battery was used in the test significantly affects the mileage returned.

I agree that series hybrid mode is evil, but sometimes cannot be avoided. I could be described as "go out of my way to avoid it". A depleted battery gives more opportunity for series hybrid operation to be needed, especially if the power demands are higher.

At the end of a drive before recharging is available, as long as the battery is depleted, may be all that is needed, and maintaining the battery until the last bit of the journey is a possible best economy strategy.

gwatpe said:

The key here is parallel hybrid mode operation and then EV mode. The test was for only 9 or so km, and the battery could have been at empty, in NORMAL mode, or at full in CHARGE mode, or somewhere between in SAVE mode. How much of the battery was used in the test significantly affects the mileage returned.

Click to expand...

Well, obviously battery power was used. Otherwise, it wasn't a hybrid vehicle. Okay, power was passed through the battery and temporarily stored there :mrgreen: .

Of course I know you mean that SOC might have been reduced during the test, resulting in a biased measurement. But I am pretty sure it was not. Obviously, the car was driving in Normal or in Save mode (otherwise, it would be almost impossible to produce this pattern) and SOC was virtually the same at the end of each cycle. IMHO, the picture tells the whole story. And the PDF where this picture comes from agrees with me, as it says (in Dutch):

"The above picture shows an example of fuel consumption recorded with a MUT-III device over a distance of 9 km traveling at 93 km/h with a depleted drive battery".

Surely as soon as you go beyond about 25 miles at non-motorway speeds you are inevitably going to be running in series mode? There are only two ways to avoid it - either don't drive very far, or drive quite quickly. I guess you can restrict the distances that you drive, but the speeds are mainly dictated by the roads you are driving on.

gwatpe said:

The key here is parallel hybrid mode operation and then EV mode. The test was for only 9 or so km, and the battery could have been at empty, in NORMAL mode, or at full in CHARGE mode, or somewhere between in SAVE mode. How much of the battery was used in the test significantly affects the mileage returned.

I agree that series hybrid mode is evil, but sometimes cannot be avoided. I could be described as "go out of my way to avoid it". A depleted battery gives more opportunity for series hybrid operation to be needed, especially if the power demands are higher.

At the end of a drive before recharging is available, as long as the battery is depleted, may be all that is needed, and maintaining the battery until the last bit of the journey is a possible best economy strategy.

Click to expand...

Yep sometimes series mode cannot be avoided but on most of my drives it can unless I go to the big smoke.

My fuel figures say that by being active with the charge button is the best possible economy strategy in my Phev and I have done the tests.

Regards Trex.