Charging the battery from the engine only

[kabousie]

Hi All,

I was wondering if any of you know how many litres of petrol it takes to charge the battery from 0% - 100%
I asked my local dealer this question and they replied it would be more expensive than electricity... Ideally this information would be handy to calculate the most cost effective journey should charging stations be faulty along the way.

Thanks

 

[anko]

During normal driving beyond EV range, the battery will be recharged by the engine automatically. This is how hybrid driving works and is efficient.

Charging the battery from the engine while stopped is not efficient. The only reasons to do so would be when you have to build op charge because you:
- are about to enter an EV only zone
- anticipate heavy towing or climbing

Btw: iirc it was about 3.5 - 4 liters or so.

 

[gwatpe]

The battery level will be maintained at close to the empty mark, and not necessarily be recharged when operating in NORMAL mode, by hybrid operations, be it series, or parallel hybrid.

Recharging from the ICE operation in CHARGE mode while stationery is not efficient. Better to preserve some battery with SAVE mode, or use CHARGE mode while driving.

There are a lot of personal strategies used by forum members that have been shared and discussed on the forum, and individual driving needs will dictate the best that will work for you.

In NORMAL mode, the PHEV will attempt to use battery energy first. OK for local, or short highway drives, [30-40km return]. Arrive at next recharging point with a flat drive battery. Works well. Whenever the longer drive, or towing is needed between recharges, with a mix of highway, and town traffic, with hills and flats, the driver will need to find their own style that best fits.

 

[anko]

The battery level will be maintained at close to the empty mark, and not necessarily be recharged when operating in NORMAL mode, by hybrid operations, be it series, or parallel hybrid.

For sure it will recharge. Even in Normal mode. Just not to 100% or anything near there . I pointed this out to explain that, although charing while driving is efficient, charging while stationary is not.

 

[kabousie]

Hi All thank you very much for the explanation.

 

[maby]

The battery level will be maintained at close to the empty mark, and not necessarily be recharged when operating in NORMAL mode, by hybrid operations, be it series, or parallel hybrid.

For sure it will recharge. Even in Normal mode. Just not to 100% or anything near there . I pointed this out to explain that, although charing while driving is efficient, charging while stationary is not.

You are being rather picky there, you know. If you let the battery go flat in Normal mode, and then drive at serial hybrid speeds, then the charge level will just oscillate around one bar which is only token charging. It is certainly true that it will recharge very slowly in Normal mode once you get up to parallel hybrid cruising speed.

 

[anko]

Sorry, bloody foreigner here. What do you mean by "token charging"?

 

[maby]

Sorry, bloody foreigner here. What do you mean by "token charging"?

Charging "in name only" - unless you push the "Charge" button or run for a long distance at a steady 50 in "Normal", it will never go above a couple of bars.

 

[anko]

The topic was about efficiency of charging the battery from the engine. Bottom line, there are two types of charging:
- charging while standing still
- charging while driving

First is not so efficient, I think we agree with that.
Second is much more efficient and does happen, regardless of using Normal mode with a depleted battery, Save mode or Charge mode.

The fact that in Normal modes it only happens in small chunks and the battery is depleted in between these chunks doesn't change anything to the above. Now, if gwatpe wants to dismiss this way of recharging because it is only in small chunks, then why am I the one being picky?
Looking closer, the fact that in Normal mode recharging only happens at low SOC even increases the efficiency of the charge process.

 

[PeterGalbavy]

I would disagree. Charging while stationary (In "P") will generate 50kW and charge the battery from empty (27%+) to either 80% or 100% depending on regions in about 30 mins and uses about 3 litres. If you charge while driving you will have less power going to the batteries as you balance driving the wheels with charging.

I am intentionally ignoring the horrible fumes from a revving, stationary engine. Which may be illegal in your locale too. And do not, under any circumstances, do this in any enclosed space such as a private or public garage.

 

[PeterGalbavy]

* Note: I would never do this though as it is always going to be more efficient (read: cheaper) driving the wheels in series or parallel mode from the ICE than charging the batteries and using those - unless you need the extra power, as previously stated, for towing or hill climbing.

 

[anko]

I would disagree. Charging while stationary (In "P") will generate 50kW

You wish . Make that about 10 or 12 kW. At 50 kW, the battery would be completely filled up in less than 10 minutes or so.

Still, the topic was about efficiency of charing, not speed of charing. If you think charging while parked is more efficient, IMHO you are definitely mistaken.


Edit -- Only now saw your second post. what exactly are you NOT agreeing with then?

 

[gwatpe]

I was wondering if any of you know how many litres of petrol it takes to charge the battery from 0% - 100%
I asked my local dealer this question and they replied it would be more expensive than electricity... Ideally this information would be handy to calculate the most cost effective journey should charging stations be faulty along the way.

I believe the first question has been answered.

There are many other factors, including weather, traffic, driving style that may have more impact on the journey costs that you may need to factor in as well. Might need a CRAY computer.

We have some conflicting discussions here on charging. I know the OP was asking about 0-100% charging.

By definition, charging means ending up at a higher %SOC, preferably, eventually back to 100%, like with a corded recharge, as this allows other beneficial battery maintenance tasks, like cell balancing, to be done on the battery. In NORMAL mode, the %SOC really does not end up at a higher level. There may be some ups and downs in time, but this is dependent on when you take a measurement. With recharging, every time you took a measurement, the %SOC would be higher. [Under constant load and speed of course]. I make no distinction between recharging and charging. The OP is talking about charging the battery back to 100% on the gauge in a single phase, and not just maintaining a particular battery level, with the engine only.

I call the small fluctuations of %SOC about a set point, as maintaining a %SOC and not discharging and recharging, even if energy [recharging] going back into the battery is a part of the process. We don't generally end up with a trend of the battery eventually being fully recharged in NORMAL mode. Some special driving may over an extended period have the %SOC increase, but an average drive in NORMAL mode will see %SOC decrease in the battery until the gauge shows about 1bar..

I have not really tested CHARGE mode, stationery or on the go. The few times I have used CHARGE mode was to test the amount of petrol that was consumed to recharge the battery, and another to bring the battery level back after I had forgotten to press SAVE mode and I needed additional battery power for a return journey home, and again when I was driving on an unfamiliar road and wanted some reserve battery just in case, and again to bring the battery level back up after the PHEV forced the battery to empty, to allow use of petrol to reach a refuel stop. This happened a few times.

I would recommend corded recharging in preference to just using the ICE. We actually have a PLUGin "HYBRID" ELECTRIC VEHICLE, and I see a mix of petrol and electric energy needed for the car to work. There are obviously two extremes here, and EV only and ICE only are the candidates. My driving needs sometimes are EV and the PHEV does it near enough for me. Sometimes I may not have corded recharging for long periods. ICE operation and hybrid EV driving still works a treat. Forum member "Trex" may be able to enlighten the forum with personal experience and any benefits gained by EV battery cycling with ICE recharging on longer drives, to answer your last question.

 

[maby]

I was wondering if any of you know how many litres of petrol it takes to charge the battery from 0% - 100%
I asked my local dealer this question and they replied it would be more expensive than electricity... Ideally this information would be handy to calculate the most cost effective journey should charging stations be faulty along the way.

...

We have some conflicting discussions here on charging. I know the OP was asking about 0-100% charging.

....

Indeed. If you drive in normal for more than about 30 miles, the charge level will drop to between zero and one bar on the gauge and then it effectively falls into a pass-through mode, at serial speeds at least, where the engine broadly produces the power that the motors need to move the car and the battery functions as a buffer to even out demand. This still has the potential to offer better fuel efficiency than an equivalent petrol engine in a non-hybrid car since it allows the power control algorithm to run the engine at a relatively constant speed closer to its best efficiency and to stop it when you stop the car. But over any moderate period of time, the power generated by the engine will be equal to that consumed by the motors and there will be no net charging effect.

If you press "Save" while the battery is partially charged, you get a similar effect with the battery oscillating around a higher charge level. Only the "Charge" button will actively increase the state of charge.

 

[PeterGalbavy]

I obv misrecalled the charge rate, but it's still impressive. Can't find the reference for 3 litres, but I am sure it was MMC that said it somewhere.

From http://media.mitsubishicars.com/releases/b3d9a889-c5c2-4f5b-abca-32c6babfe042?la=1

Battery Charge Mode

When activating the Battery Charge Mode – whether the vehicle is in motion or at a standstill – the engine will generate electricity to be fed into the lithium-ion Drive battery pack (essentially forcing the vehicle to operate in Series Hybrid mode). For example, if the engine is idling and the vehicle is not moving, selecting the Battery Charge Mode will replenish a low energy level within the lithium-ion Drive battery pack back up to 80% fully charged in approximately 40 minutes.

Also, Mitsubishi Australia are much more open with specs and details, but the config is different:

http://www.mitsubishi-motors.com.au/vehicles/outlander-phev/specifications

Generator Max. Output Generator Max. Output
70kW

Interesting comment:

http://www.mitsubishi-motors.com.au/vehicles/outlander-phev/faqs -

WHEN THE DRIVE BATTERY IS LOW, IS IT MORE EFFICIENT TO DRIVE IN CHARGING/EV MODE OR HV MODE?

Repeatedly switching between Battery Charge mode and EV mode deteriorates mileage by 20% in comparison with HV mode.

 

[anko]

I was wondering if any of you know how many litres of petrol it takes to charge the battery from 0% - 100%
I asked my local dealer this question and they replied it would be more expensive than electricity... Ideally this information would be handy to calculate the most cost effective journey should charging stations be faulty along the way.

...

We have some conflicting discussions here on charging. I know the OP was asking about 0-100% charging.

....

Indeed.

Guys, TS is also asking about "the most cost effective journey should charging stations be faulty along the way.". And then it is good to make hime aware of the fact that while driving in Normal mode, the battery is charged / SOC increased (pictures in the Tech Discussion section of the forum exactly show to what extend) during periods of parallel or serial hybrid driving, allowing for a period of EV driving thereafter, resulting in an overall fairly good fuel economy. Much better than when TS would recharge his battery when parked. If you for yourselves must classify this process as "just maintaining SOC", well that's your choice. But without this process, fuel economy would be far worse.

... the charge level will drop to between zero and one bar on the gauge and then it effectively falls into a pass-through mode, at serial speeds at least, where the engine broadly produces the power that the motors need to move the car and the battery functions as a buffer to even out demand.

Maybe this is true in your local circumstances or with your driving style, but I don't think you can post this as a general fact. There are others (yes, like myself and i believe there are many more), that actually build up EV range while driving in serial hybrid mode.

 

[anko]

Also, Mitsubishi Australia are much more open with specs and details, but the config is different:

http://www.mitsubishi-motors.com.au/vehicles/outlander-phev/specifications

Generator Max. Output Generator Max. Output
70kW

Same here. But that doesn't mean this is what you get in Charge mode while parked. This is what you get when flooring it in serial hybrid mode. In order to get these 70 kW, your engine must run under very heavy load at approx. 4100 RPM. Believe me, if your car did this on your driveway, you would know about it :mrgreen:

 

[gwatpe]

Maybe this is true in your local circumstances or with your driving style, but I don't think you can post this as a general fact. There are others (yes, like myself and i believe there are many more), that actually build up EV range while driving in serial hybrid mode.

I think we have to distinguish between charging, [energy going back into the battery] changing the guestimeter battery range, and the guestimeter battery range adjusting for changing driving conditions. I have had 46km indicated battery range with half a battery indicated, and also 88km battery range with a full battery. I also have had 12km estimated range with half the battery indicated, and 30km estimated range for a full battery.

Once we have an objective way of measuring and discussing PHEV operations, these discussions will become more meaningful.

 

[anko]

Adjusting for driving conditions has (almost) nothing to do with it. When I drive 100 km/h steady in Normal mode with a depleted battery, my EV range follows this patter: --, 1, 2, 1, --, 1, 2, and so on. It is almost like clockwork. Nothing to do with changing conditions, but a result of the car purposely charging the battery from the engine and then discharging it again. Like the blue line clearly shows in the middle section of this diagram:

Same thing happens at serial mode speeds. As a matter of fact, since the low water mark is drawn at 26% here, I believe this is actually the picture for low speeds (At higher speeds the low water mark is a tad higher). The only difference between this process at high or low speed is that power demand at low speed is typically less constant / less controlled , resulting in variations in the charge and / or discharge currents, in turn resulting in the pattern being not as constant as when driving 100 km/h using CC on the motorway.

 

[maby]

Adjusting for driving conditions has (almost) nothing to do with it. When I drive 100 km/h steady in Normal mode with a depleted battery, my EV range follows this patter: --, 1, 2, 1, --, 1, 2, and so on. It is almost like clockwork. Nothing to do with changing conditions, but a result of the car purposely charging the battery from the engine and then discharging it again. ...
Same thing happens at serial mode speeds. As a matter of fact, since the low water mark is drawn at 26% here, I believe this is actually the picture for low speeds (At higher speeds the low water mark is a tad higher). The only difference between this process at high or low speed is that power demand at low speed is typically less constant / less controlled , resulting in variations in the charge and / or discharge currents, in turn resulting in the pattern being not as constant as when driving 100 km/h using CC on the motorway.

We are arguing around terminology here - I observe the same and would not describe it as "charging" - what you are describing is what I called "pass through" - the engine is effectively generating the power requirements of the motors with the battery functioning as a buffer. For a variety of reasons, I've been driving on a flat battery for the last few days without plugging in - the SOC meter has never gone above one bar and only occasionally gone down to zero bars - that is not charging in the sense that the OP was questioning here.

On a related subject that we have discussed here, I took my wife to the station this morning and she remarked that the engine was really racing - flat battery plus moderate acceleration results in high engine revs - and this was driving at 20 or 30mph on flat suburban roads, not racing up the motorway.