Battery Save Works Until You Stop...

[anko]

a Skoda Fabia ... would be at least 50% less damaging to the environment.

Well, if you keep returning from your "beyond EV range" trips with 50% SOC left in your battery, probably it would :lol:

 

[maby]

a Skoda Fabia ... would be at least 50% less damaging to the environment.

Well, if you keep returning from your "beyond EV range" trips with 50% SOC left in your battery, probably it would :lol:

The amount of charge left in the battery would be pretty immaterial - most of the journey would be done on petrol and the PHEV at around 40mpg will be more damaging to the environment than a Fabia that can get close to 60mpg.

 

[jaapv]

... to me is a significant ca. 10% difference in economy.

To me it is too. And the environment is not impacted by fuel efficiency numbers, it is impacted by burning liters of fuel. Why would you try to save 2 liters of fuel on a short trip and not on a long trip? It is the same 2 liters. I don't get that.

Really? If I'm spending £20 on something, I will probably go out of my way to save £5. If, on the other hand, I'm spending £2000, then I'm not going to lose any sleep over £5 more or less - life's too short!

Follow up : OK, you are focussing on the environment, I'm focussing on running costs - but the same principle applies as far as I can see - if I'm worried about the environment, I should not have driven the 250km rather than being consumed with guilt about the 25km of EV I didn't use. If I am really worried about the environment, I would not have bought the PHEV at all - a Skoda Fabia would do everything I need and would be at least 50% less damaging to the environment.

But 50% more damaging to your kidneys...
BTW - my maths classes are some years behind me, but I seem to recall that 5 is not 10% of 2000...

 

[gwatpe]

My circumstances also have to fit in with the weather, and available free solar recharging resources. The PHEV is an extension of my house, that includes a wood heater, reverse cycle aircon, and battery inverter power system. I recharge my PHEV with surplus electricity from my house. In Summer, I usually return with a close to an empty battery, like others would.

I do not have to drive every day, and local drives are about 1/3 of the battery, so I don't have to recharge at every opportunity, and arriving home with some battery reserve with no immediate recharging is a good thing, especially on days with no surplus solar, like the day I went to the city. I was still able to drive EV locally the next day. There is ample solar today, so the PHEV will be fully recharged.

I just find it easier to have a user set default, "as preserving a battery level", rather than "flatten the battery first". Any driver who regularly drives beyond the 40-50km will benefit from SAVE mode, like any PHEV driver towing a caravan will benefit from CHARGE mode. There is less impact on my drives if I forget to press a button to use NORMAL mode, than if I forget to press SAVE, or CHARGE at the right time. I can still default the PHEV to be NORMAL on power ON. The PHEV probably forces the driver to consume as much petrol in a year with the normal ICE forced operation than would be used if the SAVE button was not pressed to select NORMAL mode at the right time when EV only could have been best.

We all have different values and circumstances, and preferences in cars, houses, countries we live in, comfort levels etc. If I could I would not drive myself, but have a driver. My SO does not mind being driven around. My energy savings and total environmental impact are primarily not from the PHEV alone, but include the yearly average of 2kWh per day electricity my 3 persons house consumes from the grid and a sustainable lifestyle. All those critical about how much petrol they use in their PHEV and the environmental impact of it should look at a bigger picture including the energy consumed from lifestyle, including house energy consumption, and the environmental impact of all of it.

BTW the hill is the Southern MtLofty range, and the climb has the power needle at 2pm to maintain 100kph, with approx 30kW of battery and 15L/100km petrol in parallel hybrid mode. If you miss judge speed and battery at the bottom, series hybrid only results and you can't maintain the 100kph with the ICE screaming for about 6km. My PHEV with the battery problem when driven by the MMC tech and not even towing, operated this way and it was hopeless. This is what I expect we will all find as the PHEV ages, probably past the 5 year mark, so not too much to worry about for a while.

 

[sawman82]

Good points. At the moment I am more of a city driver as I only live 6km from the CBD and rarely venture out of electric range. There are not many hills around and thus draining down the SOC and having the ICE kick in doesn't really bother that much. However I can totally understand your circumstances when I go on big drives and forget to push the SAVE button after a pit stop. You're heart sinks as you realise when you get back to town (or to the camp site where you wanted to impress your friends!) you will have no charge left unless you top it up with charge mode.

Gwatpe, are you taking orders on your save, charge mode sticky circuit? I'm an electrical engineer and would love to build my own however just don't have the time with work (where I build all the things I don't want!). If so please propose a price and PM me. I'm fine to do the install myself.

Although I expect the battery to last probably 10 years, I will be trading mine for a new model before warranty runs out. As I'm sure range will get a lot better over the coming years and lots of interesting gadgets built in. Maybe even a power socket!

 

[anko]

If you miss judge speed and battery at the bottom, series hybrid only results and

Three questions, if I may:

Are you saying that if you allow the battery to deplete before starting the climb, you end up in Turtle mode before you reach the top?

How are affairs affected by misjudging speed?

How did you determine the approx. 30 kW output of the battery during the climb?

 

[gwatpe]

If you miss judge speed and battery at the bottom, series hybrid only results and

Three questions, if I may:

Are you saying that if you allow the battery to deplete before starting the climb, you end up in Turtle mode before you reach the top?

How are affairs affected by misjudging speed?

How did you determine the approx. 30 kW output of the battery during the climb?

The hill is a regular truck and car breaker, trucks up, and down the climb, cars normally on the way up, with the bonnet up, and mainly overheating problems, by the look, when I scoot past at 100kph. My PHEV an aspire model with MMCS has display of electric motor power, so yes has approx metering of electric power. The climb at 100kph apparently requires more power than the series hybrid combination can supply, but the parallel hybrid mode, can do the job.

Never pushed the new PHEV to get turtle mode. Have managed to drive the climb with my new PHEV, always in parallel mode. My original PHEV had some issues, so the effects of reduced power were evident probably before the PHEV reached the turtle mode setting on the battery meter.

I don't get the second question! Is it technical?

 

[anko]

Thanks for getting back on my questions.

The hill is a regular truck and car breaker, trucks up, and down the climb, cars normally on the way up, with the bonnet up, and mainly overheating problems, by the look, when I scoot past at 100kph.

I see. That seems rather bad, indeed. I could imagine I would also closely monitor my SOC if I knew such a hill was upcoming. But I think it would be wrong to state that every driver would benefit from a "Use Save as much as possible" driving style, based upon your experience with this nasty hill so close to your home, as I would think your circumstances are rather exceptional.

My PHEV an aspire model with MMCS has display of electric motor power, so yes has approx metering of electric power.

Oops. Totally forgot about that dial. Don't use it anymore, as I have an OBDII solution that tells me exactly how much power goes into or out of the battery. Was wondering if you had something similar.

The climb at 100kph apparently requires more power than the series hybrid combination can supply, but the parallel hybrid mode, can do the job.

Never pushed the new PHEV to get turtle mode.

Correct me if I am wrong, but this is were you must be mistaken or your current car must also be broken. Why:

The advantage of parallel hybrid mode over serial hybrid mode is that there are no losses caused by conversions in either the generator or the E-motors. The big disadvantage of parallel mode is that the output of the engine is limited due to the fixed RPMs associated with your current speed.

There is a very clear brake even point. Above approx. 125 kph, the max output of the engine in parallel mode is more than the max output of the engine in serial mode minus the conversion losses associated with serial mode. So, above 125 kph, more engine power can be delivered to the wheels in parallel mode than can be delivered in serial mode. But at speeds below approx. 125 kph, serial mode outperforms parallel mode. This is why the the car switches to serial mode when power demand is very high in the first place and why it never does so at speeds > 125 kph in the second place.

At 125 kph, max combined system output is approx. 120 kWh, regardless of what mode you are in. As you reduce the speed, max output in serial mode stays at 120 kWh, up to speeds as low as 56 kph. But the output in parallel mode starts to reduce immediately when you start reducing speed, as you are also reducing RPMs.

So, the only situations in which parallel mode would outperform serial mode would be at speeds > 125 kph (but this is significantly faster then your speed up hill and at these speeds serial mode is not even available) or when you compare serial mode with an almost totally depleted battery (where battery output is indeed reduced) to parallel mode with a less depleted battery. But to make the last comparison, you would first have to push the car into Turtle mode. And from what I understand, you haven't.

I don't get the second question! Is it technical?

Not sure. Earlier, you wrote:

If you miss judge speed and battery at the bottom, series hybrid only results and you can't maintain the 100kph with the ICE screaming for about 6km.

I was just curious how and to what extend your initial speed would affect you ability to reach the top at a resonable speed. But it is not that important ;-)

 

[gwatpe]

Sorry - I think pushing a button at the right time is far better than an elaborate programming of the car each time you start off plus reprogramming each time the conditions change - there must be tens of thousands of variables involved.

I have to agree about the pushing the button at the right time. My observation is that SAVE or CHARGE has to be pressed in advance of the need to use it. The right time is usually 10-15, or even 30 minutes prior to when you find that pressing it would be needed. You may be unfamiliar with the road ahead. If I know that I will be travelling past the battery range, or towing tomorrow, I can set my PHEV tonight to CHARGE or SAVE mode and I won't have to remember to, tomorrow, probably after I have already depleted the battery first.

I don't believe starting in any user preferred mode, like my sticky button solution, can be classified as an elaborate programming of the car each time you start off.


Today was perfect for a drive in the country, so I have some interesting numbers. Was for an unloaded PHEV and no towing. Was able to test the PHEV on the road described above with a depleted battery.

Started the climb with 1 bar and at 100kph EV only @ 60kW electric from the battery only. The PHEV went into parallel hybrid mode, with 30kW battery and 14L/100km. This converted to 20kW battery and 18L/100km as the PHEV made some adjustments, probably as the battery was getting low. Lastly, the PHEV converted to series hybrid at 65kW and 33L/100km [the 33L/100km equaled 65kW as the battery had very little to give]. At 65kW the display went from green to orange. There were no battery bars left. ICE operated at 4100rpm in series hybrid.

The speed was constant at 100kph for the test, and the climb was over 6km. Unfortunately the PHEV had enough power reserves to climb and the Turtle mode was not seen. The screaming ICE at 4100 rpm was not pleasant. The PHEV transformed from a nice car to drive in parallel hybrid mode to a banchee in series hybrid. I found that with my unloaded PHEV on a 15% grade road at 100kph, performance is not in question. With a depleted battery, the PHEV becopmes unpleasant to drive under load when parallel hybrid operation stops and series hybrid takes over.

I can conclude that in my circumstances that the PHEV ran out of battery at about 2km, so 4km of the climb was unpleasant in series hybdid mode. This was from the typical 1bar remaining that seems to be the NORMAL mode close to empty battery cycle point. On other drives the PHEV used typically 3 bars of battery to climb the hill in parallel hybrid mode. This would have been about 25kW for 6 or so minutes averaged. This would be about 2kWh and is close to the numbers for battery stored capacity and indicated usage. To avoid series hybrid operation I would need close to 25% indicated battery reserve before the climb.

I suspect this recent discussion may not actually be related to power demands after all. As a driver, I detest the screaming of the ICE in series hybrid mode, and during my ownership of the PHEV, I have possibly modified my driving style to find a way I can maximize getting my PHEV to operate in parallel hybrid mode, and I choose when to use the battery as EV.

There may be some difference in the way the PHEV has been supplied programmed to the different regions of the world. There are many already identified differences in supplied options and it is possible that the differences may extend to the power distribution algorithms.

I do run my PHEV on Premium unleaded fuel.

I am now into my second year of ownership, and I am like many now and don't play with the gadgets until I need to. I do reset the trip meters after a full petrol refill and corded recharge. I normally leave the dash on the energy flow screen. The MMCS has the split screen with the EV and GPS map. I presently leave the sticky save mode set on power ON and push the SAVE button for NORMAL mode EV driving on short trips. I have an audio cue on the sticky save and so it is relatively easy to remember to press the button prior to driving on an EV only trip. On a longer trip I just drive and select NORMAL mode when I choose to drive EV. If I stop anywhere I don't have to remember to reselect a mode I had previously needed and would still need. I can change the stored operation of the SAVE or CHARGE mode as easily as the indicator to change direction is used.

I don't use "SAVE as much as possible". I do use SAVE as much as possible on longer trips, beyond the battery range, but still use NORMAL mode in stop/start city driving. If my driving needs were to change significantly, mainly short 20-30km EV only needed, then I would select NORMAL mode, like the factory programmed in the PHEV. I do have the option to change how my PHEV works as the default.

I do live in a regional area, so the start of my drive up to highway speeds, even in SAVE mode, is only on the battery. I suspect this may be a common scenario. The mix of windy and hilly road conditions to the city, have the ICE maintaining the battery within 1-3 bars of the start level. This is quite acceptable, as it leaves 20-30km of EV driving possible in the stop/start of the city. This does save a lot of petrol. If I power OFF, stop in the city, I just have to wait for the audible cue and press the SAVE button to continue with EV, NORMAL mode driving after powering ON again. If I forget to press a button, my longer trip default setting will leave me with a little more energy in the battery. I can accept this.

If the scenario was different, like with my factory NORMAL setting, I may be distracted with local street traffic reversing out my driveway, or even getting the bugs off the windsceen. Not pressing the SAVE at the start of the journey will cost approx 1-2km of stop/start city driving lost for every km driven on the highway, from the battery. My PHEV will not engage the parallel hybrid mode in NORMAL mode at the legal local highway speeds, so the battery will just be run down until depleted on the dash and then parallel, or series hybrid mode operates, depending on load and speed.

I do think that my driving style and mod preserves a few extra bars overall in the battery, and this results in a more pleasant drive, at the expense of a small amount of petrol, on drives that would require petrol use anyway.

We are all individuals, and I have worked out that typically, a few bars of the battery could be equivalent to taking the wrong turn off, on a motorway and having to drive further as a result. Better to have a bit more reserve battery for the potentially slower drive resulting.

Now, "Where is my Crystal Ball". :lol:

 

[anko]

Thanks for sharing your findings in such detailed way. Great stuff! A few comments:

This converted to 20kW battery and 18L/100km as the PHEV made some adjustments, probably as the battery was getting low.

It is my experience that, when running in parallel mode, the car will always try to get all the power needed for driving from the engine and only when the engine can't deliver extra power will be taken from the battery. It will not take power from the battery as long as there is surplus power available from the engine. Regardless of SOC. The fact that power was taken from the battery @ 14L/100 KM would suggest the engine was already maxed out, in which case it could not simply step up when SOC got lower. All it could do was switch to serial mode. Which it did, but not before reaching 22% SOC.

Could it be that the step up from 14L to 18L had to do with the engine reaching the proper operating temperature?

Unfortunately the PHEV had enough power reserves to climb and the Turtle mode was not seen.

Unfortunately? Serious? :lol:
It would be interesting though, to know what would have happened if the hill was any longer or, in other words, while in serial mode did SOC increase or did it further decrease? While towing, I've seen many times that the engine was able to restore SOC from 22% to 25% in serial mode and would then revert to parallel mode.

I found that with my unloaded PHEV on a 15% grade road at 100kph, performance is not in question.

Better that I dared hoping for.

the PHEV becopmes unpleasant to drive under load when parallel hybrid operation stops and series hybrid takes over

But more powerful than in parallel mode?

I can conclude that in my circumstances that the PHEV ran out of battery at about 2km

Was this where it went into parallel mode or where it went into serial mode? Next time, could you try driving with depleted batteries and hit charge at the bottom of the hill? :mrgreen:

To avoid series hybrid operation I would need close to 25% indicated battery reserve before the climb

Another way to look at it: below picture says the engine provides 48 kW at 100 kph in parallel mode. In series mode the output of the generator is 60 kW max. Ignore losses in the E-motor and the difference in power obtained from the engine between parallel and serial mode is 12 kW. Times 6 minutes is 1.2 kWh, exactly 10% of the battery capacity. Provided that SOC can drop to 22% before serial mode is enforced, 32% SOC (absolute, so only 2% indicated reserve) should be enough to start with. What does this tell us? Either you are mistaken, I am mistaken, or the car is still draining the battery, even in serial mode. :shock:

I don't use "SAVE as much as possible"

Yeah, sorry. That was my crude interpretation of

Any driver who regularly drives beyond the 40-50km will benefit from SAVE mode, ...

I do think that my driving style and mod preserves a few extra bars overall in the battery, and this results in a more pleasant drive, at the expense of a small amount of petrol, on drives that would require petrol use anyway.

I can imagine. But would have come to the same conclusion if there wasn't this 6 minute 15 pct gradient close to your home?

 

[gwatpe]

Yesterday was a special trip, so I don't expect to replicate it soon.

There is a longer, but not quite as steep drive home via the freeway, and this might be an option when towing.

I can confirm that the first step was 14L/100km plus 30kW from the battery, and then the petrol went up to 18L/100km with 20kW from the battery. ICE was already up to temp. The transition was not graded, but a step change. May be some predetermined highest efficiency ICE operating conditions used, combined with the lack of available power reserve in the battery at that point. There was only minimal time in parallel mode before the PHEV transitioned to series hybrid mode, so not much left in the battery at the 1 bar level. We really could do with a battery power meter as well as the motor power. Just need a shunt in the battery lead and somewhere to mount the panel meter :lol:

A recording system connected to the OBD2 would make any future comparisons more objective. In the mean time we just have to work out what works best for our individual needs. I just find that my needs seem to work better with me controlling when to use the battery as a default power ON, instead of the flatten battery first as factory supplied.

 

[anko]

Just need a shunt in the battery lead and somewhere to mount the panel meter :lol:

A recording system connected to the OBD2 would make any future comparisons more objective.

Seen my PM to you?

 

[gwatpe]

I have now.

Having a list of OBD codes is a good start to accessing available data. I think that recording real time data, for later analysis is a tool that all owners could benefit from. The car companies seem to want to keep things under wraps. Interested drivers could do their own thing and then share their findings and we would all benefit through distribution of the gained knowledge, even possibly, objectively working out better ways to drive our vehicles and the possible benefits to extend battery range, life and reducing wear and tear on the ICE, by managing maximum ICE rpm, battery DOD and SOC across a range of driving conditions.

Drivers could make a choice to continue their current style, or adapt the new knowledge into their own style. We are presently restricted in access tools to record driving data. The displays we have, seem deliberate in making the data difficult to record. The graphed records available in the MMCS are as useful as zits on a bull.

on a SAVE mode note:

I have an app on my phone that can display the %SOC of my house battery, and today, I was able to check in and find that I had no surplus solar at home for recharging, so I preserved the PHEV battery on my trip to the city, for possible later use, possibly the next day. I powered down at least 10 times in the city and did lose some SAVE mode setting over the day. A few bars. Majority of the battery draw down was selective EV in slow and stop/start traffic. About 50%. arrived home with just under half the battery. Had reserve for local EV driving after I got home. Battery ended up with a couple of bars remaining tonight. Today was a good example of why preserving the battery can allow for unexpected driving needs. If the battery had been empty, then I would have burned petrol for the local driving. We know how this loses brownie points. :lol:

 

[Neverfuel]

Surely "greenie" points, not "brownie" points Gwatpe?

 

[gwatpe]

Surely "greenie" points, not "brownie" points Gwatpe?

My sister used to get "brownie points" for being good. I suppose that in this modern era, being green equates to the same. Brownie had a good meaning in the past.

On a related to SAVE note. My PHEV has a depleted battery at the moment, down to 1 bar. The computer has the remaining capacity stored as 00 7d, so 12.5Ah. The total capacity is presently 37.4Ah, so the %SOC at 1 bar remaining is about 33%. This may explain why I have been unable to get the turtle screen. Still quite a way to go, and I give up trying to get there and just slow down a bit, or run out of hill.

the 762 23 _ _ . . . . 01 XX _ _ does not appear to be pack voltage.