Does my "Accumulate" mode in PHEV make sense?

[zzcoopej]

Scenario : Long Trip -
A) Local Road to start trip, then
B) Highway driving, no chance of plugging in, then
C) Local Road to end trip

1. Drive in EV mode for (A)
2. Hit "Save" when entering highway (B), as we are told to do by Mitsubishi.
3. Notice when battery level increases due to excess parallel mode energy being stored during some periods where less energy required to drive PHEV.
4. After battery increase, cancel "Save" during a downhill slope after petrol engine switches off.
5. Hit "Save" again before the PHEV drives in EV mode, preventing the drop in battery level back to the previously "saved" level.
6. Battery level starts accumulating, ie it is stored away for the local road part of the trip (C).

I am interested in whether this makes sense? I tried it on a recent trip and it was going very well. I managed to "Accumulate" about 16km EV range (1/4 battery) over about 500km, however I was foiled by the "gotcha" of the PHEV stealing the battery when the fuel level gets down to 4L.

 

[Trex]

Gday zzcoopej,

Yes any way of avoiding slow speed series mode (your "local road part of the trip (C)") I find reduces my fuel consumption in my phev. ie be in ev mode for slow sections.

Regards Trex.

 

[anko]

What do you mean by:

3. Notice when battery level increases due to excess parallel mode energy being stored during some periods where less energy required to drive PHEV.

I mean, if SOC starts to drift up, it would go back into EV mode, right?

 

[Trex]

What do you mean by:

3. Notice when battery level increases due to excess parallel mode energy being stored during some periods where less energy required to drive PHEV.

I mean, if SOC starts to drift up, it would go back into EV mode, right?

I do not use the save button only charge button but his No 4. and 5. I think would accumulate SOC.

 

[zzcoopej]

What do you mean by:

3. Notice when battery level increases due to excess parallel mode energy being stored during some periods where less energy required to drive PHEV.

I mean, if SOC starts to drift up, it would go back into EV mode, right?

What I have noticed is that there is a bit of a "range" where SOC cycles in Save mode, however I did not have my App running to see what the range of SOC is (lets assume it is 1Ah). The strategy seems to grab the top of this SOC range (ie increase of say 1Ah) and then allow you to capture the next 1Ah of "Save mode" SOC range by starting a new "Save mode" setpoint?

 

[Trex]

What do you mean by:

3. Notice when battery level increases due to excess parallel mode energy being stored during some periods where less energy required to drive PHEV.

I mean, if SOC starts to drift up, it would go back into EV mode, right?

What I have noticed is that there is a bit of a "range" where SOC cycles in Save mode, however I did not have my App running to see what the range of SOC is (lets assume it is 1Ah). The strategy seems to grab the top of this SOC range (ie increase of say 1Ah) and then allow you to capture the next 1Ah of "Save mode" SOC range by starting a new "Save mode" setpoint?

Gday zzcoopej:

I am not anko but to me it seems to infer that you are just reducing the amount of Ev the phev could have gone into. I will bring in a image to show what I mean.



Notice where it says battery save with a sawtooth line in green which represents the Phev running in hybrid mode of charge, ev, charge, ev (this happens automatically if the loads on the phev are low enough).

It looks to me that you are just grabbing the tops of the sawtooth line and stopping the downward slope of the ev portion of the line by what you just posted.

The charge button does the same thing and maybe more suitable for doing that in my opinion.

I hope I understand what you meant and I hope you understand what I am trying to say too.

Regards Trex.

 

[zzcoopej]

It looks to me that you are just grabbing the tops of the sawtooth line and stopping the downward slope of the ev portion of the line by what you just posted.

Yes I agree, to make more of a staircase.

The charge button does the same thing and maybe more suitable for doing that in my opinion.

I hadn't thought of that, and you are correct that Accumulate is like Charge. However I would think with the goal of charging the battery this would be more aggressive ie even going down hills it would run the ICE? In my use, the ICE only operates on level or uphill.

 

[anko]

I am not anko but ...

And let us all be happy about that, as one is more than enough :mrgreen: . Nevertheless, he agrees with you. Based upon what zzcoopej wrote in his last post.

Although, how do you prevent the downward slope of the SOC cycle when there is no downhill slope to drive on near by? Other than by pressing the same Charge button?

 

[zzcoopej]

how do you prevent the downward slope of the SOC cycle ?

When I tried this, the Save button was on 95% of the time. I just clicked it off every now and then for a few seconds which seems to reset the "SOC target/setpoint" to a higher value (I am assuming).

So I guess this "Accumulate" is in between Save and Charge?

My theory is that the downward tooth in the graph is wasteful at highway speeds, it is better accumulated for the slower part of the trip?

 

[anko]

In the office now. Just did 60 miles of motorway, allowing me to test a bit. Indeed, briefly disengaging Save mode resets the (lower) baseline for the cycle. Equally, when you switch from Charge to Save mode, you first enter the upward bit of the cycle.

I cannot see any advantage over simply using Charge mode. Only disadvantages as your strategy involves stopping and restarting the engine frequently, when charge mode keeps there engine running.

One thing to be aware of is this: when you are on a downhill slope at parallel+ speed with Charge mode engaged, the dash may give you the impression the engine is not running, where it is actually running but not doing any useful work. It is just consuming enough fuel to overcome its own internal resistance (like 2 l/100 km @ 100 km/h). So, under certain circumstances,it might be sensible to turn of Charge mode when coasting downhill.