Do not be scared of using that charge button.

[Trex]

I have noticed there is still some chatter about the charge button. Have seen statements like it will make your fuel consumption worse because it is adding extra conversion processes ie petrol to electricity into battery and battery to electric motors to turn the wheels etc etc.

Now I would, and have, normally discussed this sort of topic in the Technical sections but it is here in General that that I mostly notice this sort of discussion. I think some here may not visit over there or if they do never get involved in the discussions there for "fear" of showing their ignorance on the matter or lack of education in such details. If you feel that way I would suggest taking that first step and asking some questions over there in Technical if you want to learn more about this, I think, wonderful car. There are plenty of members here to help you. Remember we were all new or beginners once. I know I am still learning.

Now back to the topic of the charge button.

It may come as a surprise to some here that the charge button is nothing but something the PHEV is trying to do most of the time the petrol motor is running anyway ie charging up the drive battery. That's right, I will say it again, nearly every time the petrol motor runs the PHEV is trying to charge the battery if the load on it is light.

Now that in itself IMO is the hardest thing for us to get our heads around.Why would it try to do that? Sounds inefficient and wasteful of fuel. Charge the battery every time it runs IF it can. Sounds B/S. How does he know this?

I have just spent days reloading some old and new pretty pictures. Lets bring in some because I love pretty pictures and I hope you do too.



Please do not let this graph scare any of you. It is nothing but snapshot of time of a PHEV running along the road travelling at 92.75 kph (see Vehicle Speed row) in Parallel mode. If you do not know what parallel mode is or does please ask. No one worth their salt will jump down your throat IMO.

Now see Engine Revolution going from 2454 revs/min to zero and back up to 2454 revs/min and repeating. That is our PHEV petrol motor starting and stopping as we drive.
I still think it is amazing and I have owned 3 hybrid cars. I still own 2.

Again you can see the Instantaneous Fuel Consumption row. 10.03 Litres of fuel per hour every time the petrol motor runs and then a big fat 0 when it stops.

So what is happening here? It is nothing but Mitsubishi showing us that every time the petrol motor runs in the PHEV if the conditions are right it will CHARGE the drive battery so it can shut down the petrol motor later.

Now another pretty picture. After 2 days of working on them I want to show them off.



Again, do not let some graph frighten you. Ask those questions if you do not understand. There is no such thing as stupid question I think.

So see those squiggly or what are known as sawtooth (look like a saw) lines. Again it is nothing but Mitsubishi showing us the PHEV starting the petrol motor and charging up the Drive battery then stopping the petrol motor and going into EV mode if the conditions are right every time we drive in hybrid mode.

If it so inefficient pushing that charge button as I have seen some claim here why is Mitsubishi and Toyota with prius etc doing exactly that with their programming of the petrol motor when the conditions are right.

It is because that petrol motor is so inefficient in the first place. Especially under light load conditions eg cruising along at 100kph or 60mph along a flat road and NOT pulling a trailer etc.

A petrol motor is actually at its most efficient when that throttle plate that controls the air to allow for combustion of the fuel is fully open and at certain higher load on the motor. For instance a petrol motor is very inefficient at idle if it was running at the traffic lights when stopped. Unless it was charging a drive battery and even then I would not recommend that. That's another story.

So what does Mitsubishi and Toyota do if the petrol motor needs to run to keep us going and we are just cruising along with a light load on the petrol motor. That right, they increase the load on the petrol motor by generating electricity to be stored in drive battery and after awhile they shut down that bloody inefficient petrol motor and we cruise along in EV mode.

Now that charge button. All it does is keep the petrol motor going longer and charging up the drive battery for longer than Mitsubishi normally plans. At exactly the same rate as the PHEV normally charges. That is good for building up a charge to climb mountains etc but is also good for avoiding series mode when we come to towns and cities IMO.

But that is another story.

I had better finish here before the moderators chuck me out for putting this in the general section.

I hope it helps and I know I have explained this before over in Technical but just trying to stop what I think are wrong or misleading statements made by some members here.

Regards Trex.

Ps If anyone can help me explain it better please do. I am not a teacher as such. Just a lowly engineer that loves pretty pictures.

[WAH64]

Hi Trex, very clear and very interesting.

Despite being an engineer, I have never used the Charge mode assuming it to be inefficient.

Let’s discuss an example journey: 20 miles city driving (EV or series mode) followed by 100 miles motorway (parallel mode) followed by a further 20 miles city driving. I have always driven this by selecting EV in first city stretch, Save on motorway, Normal mode in final city stretch where the car does its own thing between EV and Series modes.

What I think you are saying is that on the same journey I might use less petrol if I used EV mode on first city section, then a mix of Charge and Save on the motorway so that I put back sufficiient Charge to complete the final city section in EV mode.

I shall certainly try it out.

[Sumpy]

Hello Trex, I like the way you have explained how the PHEV operates, especially the graphs
When I go on a longer trip (400+ miles with only a charge before leaving) I select save when the battery is about 75% full, and have found that the car will recharge itself back to that level even if I have drained it after a few hills or a bit of spirited overtaking , so I don't really ever need to use the charge button, because the car is already doing it anyway.
I wouldn't say I'm scared of using the charge button, but I find the burning smell a little disconcerting, I know some have said that this reduces over time, and to be honest I don't notice it anymore, but then I don't really use it that often (only when on the 400+ mile trip and I forget to select save after stopping ).

[jdsx]

Interesting discussion. So here is a question. My only regular out-of-EV range journey is from home (NW of Glasgow city centre) to Edinburgh (just SE of city centre) and back - about 60 miles each way.

Assuming I cannot charge anywhere en route, what I would usually do is use battery to get to the motorway (about 6 miles), press Save until I get to the outskirts of Edinburgh (so EV range on motorway remains approx 16 miles during this time), then press Save again to use EV mode within Edinburgh if I can. At destination in Edinburgh, EV range would read about 11-12 miles. Return is the same... use EV to get back to motorway, then press Save to keep 6-7 miles range left which I use to try to get back home (from the motorway) having just used the last bit of battery as I get back! (This works during the summer but is a stretch during the winter!)

I have been debating if I would be better pressing 'Charge' on the motorway in each direction to get the EV range remaining up - so just using the ICE for longer period, say to get EV range up to 18 miles on the way home.

TBH I don't think it would make a huge difference one way or the other, but presumably it must be better to run the ICE for one long-ish section in the middle rather than for multiple short sections, which is what it does on 'Save'....

Thoughts? Does 'Charge' automatically turn itself off over 75-80%?

[Sumpy]

TBH I don't think it would make a huge difference one way or the other, but presumably it must be better to run the ICE for one long-ish section in the middle rather than for multiple short sections, which is what it does on 'Save'....

I agree about running the engine for one continuous spell as opposed to stopping and starting as it does in save mode, but the long journey that I do is mostly A roads which seems to be one roundabout or junction after another, and sitting at a junction or roundabout with the engine revving whilst in charge mode doesn't make for a relaxed journey. After my early concerns about engine wear caused by continually stopping and starting, there doesn't seem to be a reliability problem and Mitsubishi appear (so far) to have done a good job (IMO)

[anko]

TBH I don't think it would make a huge difference one way or the other, but presumably it must be better to run the ICE for one long-ish section in the middle rather than for multiple short sections, which is what it does on 'Save'....

I agree about running the engine for one continuous spell as opposed to stopping and starting as it does in save mode, but the long journey that I do is mostly A roads which seems to be one roundabout or junction after another, and sitting at a junction or roundabout with the engine revving whilst in charge mode doesn't make for a relaxed journey. After my early concerns about engine wear caused by continually stopping and starting, there doesn't seem to be a reliability problem and Mitsubishi appear (so far) to have done a good job (IMO)

Also consider heating. If your engine is on first half of the trip and off second half of the trip, most likely you will need electricity for heating at some point. When the engine is on and off intermittently, you may be able to do without.

[Hypermiler]

Thanks for that Trex.
I'm glad to read that I am doing something right. I use charge more than I use save because I then have control over when the ice runs. I hate the ice runnning in inefficient mode - always trying to keep the orange direct drive arrow. I turn it on and off frequently - it is a hybrid so designed to stop and start. I take into account all the points raised - one long ice run vs heating requirement etc. By the time I get to the motorway my battery will only be about 1/3 full. I let the car roll down hills and charge to a bit over 1/2 full to cope with any jams. I rarely let the battery get to zero except at the end of a journey and so cannot contribute to the constant Facebook discussions about how much you get out of one charge on ev only - I actively manage my ice use on every out of range trip.
Cheers
H

[Hypermiler]

And my slightly rubbish looking fuelly mpg is because I do a lot of towing...

[Trex]

Hi Trex, very clear and very interesting.

Despite being an engineer, I have never used the Charge mode assuming it to be inefficient.

Let’s discuss an example journey: 20 miles city driving (EV or series mode) followed by 100 miles motorway (parallel mode) followed by a further 20 miles city driving. I have always driven this by selecting EV in first city stretch, Save on motorway, Normal mode in final city stretch where the car does its own thing between EV and Series modes.

What I think you are saying is that on the same journey I might use less petrol if I used EV mode on first city section, then a mix of Charge and Save on the motorway so that I put back sufficiient Charge to complete the final city section in EV mode.

I shall certainly try it out.

Hi Chris,

Yes I use the Charge button to pump up the drive battery in parallel mode before I get to cities or towns to avoid series mode.

It gives me my best measurable fuel economy savings. That plus not travelling everywhere with a full drive battery.

Regards Trex.

[Trex]

Hello Trex, I like the way you have explained how the PHEV operates, especially the graphs
When I go on a longer trip (400+ miles with only a charge before leaving) I select save when the battery is about 75% full, and have found that the car will recharge itself back to that level even if I have drained it after a few hills or a bit of spirited overtaking , so I don't really ever need to use the charge button, because the car is already doing it anyway.
I wouldn't say I'm scared of using the charge button, but I find the burning smell a little disconcerting, I know some have said that this reduces over time, and to be honest I don't notice it anymore, but then I don't really use it that often (only when on the 400+ mile trip and I forget to select save after stopping ).

Hi again Sumpy,
Thanks for kind words. I sometimes wonder if I am making any sense to others especially when you do not know their experience in these matters so I probably carry on too much with the trivea. Graphs? Oh you mean the pretty pictures.

Sorry, that is just a joke about when a mate was having a shot at me about having to use graphs for my job and I replied "yea I just like the "pretty pictures".

But I am just trying to bring in a bit of humour to something that can be probably considered very boring when I call them pretty pictures.

That burning smell is defiantly gone on my PHEV. I think it was something they had sprayed on the exhaust and elsewhere when manufactured to stop corrosion on the boat trip over here. But I am only guessing.

Regards Trex.