Battery range

[GolfjunkyC60]

Thanks.

 

[anko]

The Charge button is more problematic. In theory it should be pretty inefficient - you are burning petrol to push charge into your battery - with inevitable losses - and then later drawing on that charge to drive the motors - again with losses.

And how does Save mode not do exactly the same? :roll:

 

[anko]

The car will certainly slightly increase charge during high speed motorway driving in Save mode, but the increase is small unless you actually hit Charge rather than Save.

Save mode should not increase SOC at all (unless under very special circumstances, but it can loose SOC just as easy), unless you are referring only to the periods during which the engine is running. If this is what you meant, Save will add as much energy to the battery as Charge will.

 

[maby]

The Charge button is more problematic. In theory it should be pretty inefficient - you are burning petrol to push charge into your battery - with inevitable losses - and then later drawing on that charge to drive the motors - again with losses.

And how does Save mode not do exactly the same? :roll:

While Save may drive some charge into the battery, I believe that its primary effect is to put it onto float charge - the bulk of the power coming out of the generator goes directly into the motors rather than through the battery and back out. We have already established that it is not a two port battery that can simultaneously be charged and discharged. On Save mode, the car certainly does occasionally drop into EV and run on stored charge for a while, but cruising at relatively high speed in parallel hybrid it spends the majority of the time running on petrol with the display indicating a low level of charging.

 

[maby]

The car will certainly slightly increase charge during high speed motorway driving in Save mode, but the increase is small unless you actually hit Charge rather than Save.

Save mode should not increase SOC at all (unless under very special circumstances, but it can loose SOC just as easy), unless you are referring only to the periods during which the engine is running. If this is what you meant, Save will add as much energy to the battery as Charge will.

I don't agree that Save will add as much energy to the battery as Charge when running in parallel hybrid mode. My car spends most of its life cruising at around 60mph in parallel hybrid with Save selected - and it is running on petrol almost all the time with the SOC more or less constant. The power flow display is usually showing the direct physical drive to the front wheels from the engine and a level of charge from the generator to the battery but no power flow from the battery to either the front or rear wheels. The level of charging is pretty low - very occasionally, it drops into pure EV for perhaps a mile but this is rare. The car will run like this for hours and returns around 43mpg.

At similar speeds in Charge mode, it does increase the SOC noticeably and the fuel consumption goes up.

 

[anko]

I'm dubious that using 'Charge' can ever result in a fuel saving, purely because there are bound to be efficiency losses in charging the battery and then discharging it again.

Let's assume that your trip is beyond EV range and you run a 5 miles short. The last 10 miles are low speed. Then you have two options:

- Use charge during the last high speed part of your trip and do the last 10 miles of low speed in EV mode.
- Do not use charge during the last high speed part of your trip and do the last 5 miles of low speed on petrol.

In both cases, some electricity is pushed into the batteries and pulled out again to be used later. But in the first case, during the high speed part in Charge mode, quite a lot of power is fed directly from the engine to the wheels without the need of it being converted to electrical power by the generator and back to mechanical power by the E-motors. The must count for something?

 

[anko]

... with the display indicating a low level of charging.

What display might that be?

 

[maby]

... with the display indicating a low level of charging.

What display might that be?

A combination of the power flow that shows charging and the fact that the SOC meter does not rise significantly.

 

[anko]

I don't agree that Save will add as much energy to the battery as Charge when running in parallel hybrid mode. My car spends most of its life cruising at around 60mph in parallel hybrid with Save selected - and it is running on petrol almost all the time with the SOC more or less constant. The power flow display is usually showing the direct physical drive to the front wheels from the engine and a level of charge from the generator to the battery but no power flow from the battery to either the front or rear wheels. The level of charging is pretty low - very occasionally, it drops into pure EV for perhaps a mile but this is rare. The car will run like this for hours and returns around 43mpg.

At similar speeds in Charge mode, it does increase the SOC noticeably and the fuel consumption goes up.

When I drive 60 MPH in Save mode, my engine will be off for about 35 - 40% of the time. Just as if I was not using Save mode and the battery was depleted. If your car does not regularly drop into EV mode under these circumstances, I suspect it is broken.

Furthermore, I have the means of monitoring instantaneous fuel consumption as well as the actual amount of power being fed into the battery. Via EvBatMon or via my own tools. And I can tell you that, when driving 60 MPH in parallel mode, I can switch between Save and Charge mode a zillion times, but it does not have any effect whatsoever, nor on fuel consumption, nor on charge current.

I really think you got it wrong. Or it must be a consequence of maintaining a very high SOC.

... with the display indicating a low level of charging.

What display might that be?

A combination of the power flow that shows charging and the fact that the SOC meter does not rise significantly.

Hitting Save mode starts a hysteresis cycle that lets SOC fluctuate by 1.5%. Not something you are likely to capture on the SOC meter, as a single bar represents roughly 4.5% SOC.

Either way, I see three possibilities:
- You fail to notice the periods of EV driving that happen between the periods of parallel hybrid driving
- Your car is broken
- Due to the very high SOC, the charge current is reduced so far, that it takes the engine forever to raise SOC by 1.5%.

Either way, the number of revs my engine does per distance travelled will be about 35 - 40% less than yours does. I prefer mine.

 

[maby]

I suspect that it is mostly down to keeping the SOC high.

 

[gwatpe]

When I drive 60 MPH in Save mode, my engine will be off for about 35 - 40% of the time. Just as if I was not using Save mode and the battery was depleted. If your car does not regularly drop into EV mode under these circumstances, I suspect it is broken.

I suspect the SAVE level was about 28%. Shown as battery gauge 0.

I will be travelling again tomorrow approx 2500km, and will try and record my PHEV's % ICE operation with torquePRO, at reducing battery charge levels.

My PHEV has had around 20% EV operation at various battery levels in SAVE mode when driven at 100kph, but never as high as 40%. It must be broken as well??

 

[greendwarf]

I don't know what Anko's on about here, but his apparent suggestion that driving in Save & Charge produce the same results is wrong - but for the OP's benefit they are both really about managing battery for EV driving in urban areas to reduce pollution not economy (although EV is more efficient at lower speed) .

Last weekend I did a round trip out on London and used both. When in Save, the SoC was maintained (judging by the battery level indicator on the dashboard) and after using it all in urban driving in Southend, using Charge on the return trip pushed up the SoC enough to give me EV driving again in London.

This increase in battery energy had to come from somewhere - i.e. increased petrol consumption, simples

 

[jaapv]

But at least you regained by "driving" in London on EV instead of standing with the engine running - AKA mpg infinite.

 

[anko]

I don't know what Anko's on about here, but his apparent suggestion that driving in Save & Charge produce the same results is wrong

Of course you can are allowed to say this, but then please tell me what is wrong about my 'suggestion', what would be the right 'suggestion' in your opinion and what you are basing that upon.

Also, you must warn zzcoopej that EvBatMon is wrong

 

[maby]

I watched it carefully this morning on our way to Southampton, and experimented. We left the house at around 7am with a full battery and the air temperature around 4C. The motorways were pretty clear, so I was able to leave the car on cruise control at 60mph all the time. I put it straight into Save with the battery at 100% and the car went into serial hybrid and stayed like that with the engine running continuously. I gave it a few miles to warm up, then reset the fuel consumption meter. It settled immediately on 41.9mpg and stayed at that figure. I let it run for a bit longer, then reset the meter meter - it went to 41.8 again. I ran for about 30 miles like this with the car in serial hybrid and the engine on full time.

I then dropped it out of Save mode and let it discharge the battery to about 70% before going back to save - now it went to Parallel Hybrid with no drive showing to the electric motors, direct drive to the front wheels and charge to the battery indicated. The battery SOC did rise slowly and it occasionally dropped into EV but very rarely. Displayed fuel consumption was far more variable, ranging between 30 and 48 mpg, but selling around 43mpg most of the time. We arrived in Southampton with one more bar on the SOC meter than when I had pressed the Save button.

This is pretty consistent with the last test I ran over the same route - possibly a small improvement in fuel consumption by letting the battery discharge, but not enough to justify changing your pattern of usage if you find the car more pleasent to drive on a well charged battery. Equally, people getting 30mpg or worse on moderate runs need to look at their driving styles.

 

[greendwarf]

I don't know what Anko's on about here, but his apparent suggestion that driving in Save & Charge produce the same results is wrong

Of course you can are allowed to say this, but then please tell me what is wrong about my 'suggestion', what would be the right 'suggestion' in your opinion and what you are basing that upon.

Also, you must warn zzcoopej that EvBatMon is wrong

golfjunky is a newbie and was asking a simple question about the difference between Save & Charge. Your reply seemed to suggested there was no difference. Whilst I accept that in overall petrol only mpg there will be none (or little) I think this is likely to confuse someone who has not had the benefit of reading this forum for 2 years nor actually using the car yet.

When you are driving in Save you are using less petrol, at the same speed, than when you are in Charge - basis physics. What I assume you are talking about is the overall picture but that will depend on individual use patterns including static grid charging. This is why I referred him/her to the environmental "benefits"

 

[anko]

golfjunky is a newbie and was asking a simple question about the difference between Save & Charge. Your reply seemed to suggested there was no difference. Whilst I accept that in overall petrol only mpg there will be none (or little) I think this is likely to confuse someone who has not had the benefit of reading this forum for 2 years nor actually using the car yet.

When you are driving in Save you are using less petrol, at the same speed, than when you are in Charge - basis physics. What I assume you are talking about is the overall picture but that will depend on individual use patterns including static grid charging. This is why I referred him/her to the environmental "benefits"

In the responses in which I said there was no difference, I was explicitly referring to "the periods during Save mode when the engine was running" and "parallel hybrid mode" (which also implies a running engine). And with the engine running, I still believe that there is no difference between Save and Charge mode.

I also said that Save mode in general should not increase SOC, where Charge mode should, referring to the fundamental (if not only) difference between the two modes.

So, when comparing Save mode to Charge mode head on, there should be no difference in terms of instantaneous MPG (where applicable, so with the engine running), but in terms of overall MPG (which would include periods of EV driving in Save mode) it is expected that fuel consumption is higher in Charge mode, resulting in a higher SOC at the end.

 

[anko]

I put it straight into Save with the battery at 100% and the car went into serial hybrid and stayed like that with the engine running continuously. I gave it a few miles to warm up, then reset the fuel consumption meter. It settled immediately on 41.9mpg and stayed at that figure. I let it run for a bit longer, then reset the meter meter - it went to 41.8 again. I ran for about 30 miles like this with the car in serial hybrid and the engine on full time.

Interesting to read. I know of two situations where the engine will not produce additional power to charge the battery (apart from high demand situations where more than 75% of available power is needed for propulsion):
- When the engine is started for heating purposes
- When the battery is depleted and the fuel tank near empty (in this situation, the Save and Charge buttons do not work anymore)

In both cases, the car will not engage in parallel mode even when driving at parallel mode speeds. You now describe a third situation where the engine will not produce additional power to charge the battery (extremely high SOC) and, from what you are saying, again the car will not engage in parallel mode in this situation.

Maybe it is because when doing 60 mph in parallel mode without the possibility to produce some additional power (and dump it into the battery) the engine load is so low that it runs very inefficient. And probably it is more efficient to run at a higher load at lower RPMs. But this requires serial hybrid mode.

For me, creating a situation in which the car was running in serial mode at parallel mode speeds would be an absolute NO. I mean, if serial mode at parallel mode speeds would be anywhere near as efficient as parallel mode, Mitsubishi would probably have left out the parallel drive option completely and saved a lot of weight / money.

I then dropped it out of Save mode and let it discharge the battery to about 70% before going back to save - now it went to Parallel Hybrid with no drive showing to the electric motors, direct drive to the front wheels and charge to the battery indicated. The battery SOC did rise slowly and it occasionally dropped into EV but very rarely. Displayed fuel consumption was far more variable, ranging between 30 and 48 mpg, but selling around 43mpg most of the time. We arrived in Southampton with one more bar on the SOC meter than when I had pressed the Save button.

This is pretty consistent with the last test I ran over the same route - possibly a small improvement in fuel consumption by letting the battery discharge, but not enough to justify changing your pattern of usage if you find the car more pleasent to drive on a well charged battery. Equally, people getting 30mpg or worse on moderate runs need to look at their driving styles.

One bar extra could mean just 0.5% SOC. Could be a result of ending the hysteresis cycle 'at the top'. Or of regen when slowing down at the end of your trip.

Next weekend, please do the same experiment but let it drop to < 50% SOC. Because I am pretty sure it will drop into EV mode more often than. And will give you an even better milage. At least it will result in less wear to the engine.

 

[SolarBoy]

My battery range is showing 30 miles.

Is my PHEV faulty?

 

[greendwarf]

In the responses in which I said there was no difference, I was explicitly referring to "the periods during Save mode when the engine was running" and "parallel hybrid mode" (which also implies a running engine). And with the engine running, I still believe that there is no difference between Save and Charge mode.

I also said that Save mode in general should not increase SOC, where Charge mode should, referring to the fundamental (if not only) difference between the two modes.

So, when comparing Save mode to Charge mode head on, there should be no difference in terms of instantaneous MPG (where applicable, so with the engine running), but in terms of overall MPG (which would include periods of EV driving in Save mode) it is expected that fuel consumption is higher in Charge mode, resulting in a higher SOC at the end.

So where does the energy, stored in the Battery in Charge when the ICE is running, go when it is in Save, with the ICE running, to achieve the same mpg?

OR are you really saying that, in fact, when in Save, what actually happens is that the car is first in Charge mode, builds up some "spare" battery and then goes to EV. In other words there is no such thing as Save mode merely short periods of switching between Charge and EV?