Charging from the engine

[JonPaul]

Is there any info out there for how much the increased fuel consumption is if you're asking the engine to charge the battery as well as power the wheels?

 

[subuPHEV]

the instantaneous fuel consumption bar oscillates between 10 to 15 liter/100km while charging from the engine

 

[kpetrov]

Is there any info out there for how much the increased fuel consumption is if you're asking the engine to charge the battery as well as power the wheels?

The fuel consumption in parallel mode (engine charging the battery as well as power the wheels) is not increased! Increased compared to what btw?
Even the opposite, parallel mode is the most efficient way to use the engine.

 

[twosout]

Not sure why you ask nor, exactly, what you are asking for?
I only put mine into "Charge" mode occasionally, when I'm on a motorway and consider that I may need more EV (than I have "Saved") later in the journey (eg. for slow or hilly roads) where EV might be more efficient than ICE.
I'm sure that generating electricity from petrol is more expensive than getting it from the grid, so gereally avoid doing so.

 

[nrayanov]

Charge mode only makes sense when camping, towing, or driving on the highway.

 

[kpetrov]

Charge mode only makes sense when camping, towing, or driving on the highway.

Of course only on the highway.
Like Save or any engine use should be on highway if possible. That's why Charge is useful... to accumulate charge on highway and avoid using the engine in slow speeds.

 

[Trudgy]

In my testing. Driving on the highway with the engine going (battery at 0 or close to) I'd get around 8-9 L/100kms , if I turned on charge mode I would get 12-13L/100kms

So I'd say it uses about 4 litres per 100kms

 

[chrisQT]

In my testing. Driving on the highway with the engine going (battery at 0 or close to) I'd get around 8-9 L/100kms , if I turned on charge mode I would get 12-13L/100kms

So I'd say it uses about 4 litres per 100kms

How long does it take to fully charge from the engine?

 

[BobK]

Charge mode only makes sense when camping, towing, or driving on the highway.

I've used it when towing, but the engine often revs quite high. The Outlander has a pretty low towing rating, so I wonder if Charge Mode while towing a large load puts undue stress on the engine?

 

[littlescrote]

How long is a piece of string?

 

[greendwarf]

Do you mean when travelling or stationary?

More to the point, why?

 

[kpetrov]

I've used it when towing, but the engine often revs quite high. The Outlander has a pretty low towing rating, so I wonder if Charge Mode while towing a large load puts undue stress on the engine?

What is happening with your engine and for how long if you don't use Charge when towing!?

 

[Ecological]

I've used it when towing, but the engine often revs quite high. The Outlander has a pretty low towing rating, so I wonder if Charge Mode while towing a large load puts undue stress on the engine?

Of course it does. It also reduces the life span of the car. The harder the engine works, the less it will last. It is no different than a human being. If you burn your candle at both ends, get little sleep, smoke a lot...you will die earlier. That is generally true..but not always. That is why we do not like to buy second hand cars. How do we know if it has been driven mostly at 40 mph or it has been raved at 80 mph. No way of knowing but we would choose the car that was driven carefully at 40mph instead of 80mph most of its life without towing. Fair enough you may be able to check how many miles it has done, or whether it had been involved in an accident. You cannot however check how it was driven, and whether it was towing most of its life.

 

[BobK]

What is happening with your engine and for how long if you don't use Charge when towing!?

Of course it does. It also reduces the life span of the car. The harder the engine works, the less it will last. It is no different than a human being. If you burn your candle at both ends, get little sleep, smoke a lot...you will die earlier. That is generally true..but not always. That is why we do not like to buy second hand cars. How do we know if it has been driven mostly at 40 mph or it has been raved at 80 mph. No way of knowing but we would choose the car that was driven carefully at 40mph instead of 80mph most of its life without towing. Fair enough you may be able to check how many miles it has done, or whether it had been involved in an accident. You cannot however check how it was driven, and whether it was towing most of its life.

What is happening with your engine and for how long if you don't use Charge when towing!?

If I just keep it in Normal and don't use Charge, after warming up for a few km in ICE mode, it will switch to EV mode and exhaust the battery pretty quickly, then continue on in ICE mode. The engine usually has normal sounding revs (though the power guage reads a bit higher) similar to travelling in ICE mode without a trailer on the highway. I assume the clutch is engaging and I am getting direct drive to the wheels. However, going up a somewhat steep incline when the battery is drained results in high revs (even at slower speeds) which I think means it is switching to serial mode and running the generator heavily. My current strategy is to switch to Safe mode with the battery half full so as to have the reserve to go up hills in parallel mode. Haven't done enough towing yet in this mode to reach a conclusion as to whether it works better.

 

[kpetrov]

If I just keep it in Normal and don't use Charge, after warming up for a few km in ICE mode, it will switch to EV mode and exhaust the battery pretty quickly, then continue on in ICE mode. The engine usually has normal sounding revs (though the power guage reads a bit higher) similar to travelling in ICE mode without a trailer on the highway. I assume the clutch is engaging and I am getting direct drive to the wheels.

Don't you realize that what you are describing is the vehicle goes in to Charge mode automatically once your battery is exhausted? Exactly the same is happening when you press Charge. The clutch is engaging and you have direct drive to the front wheels, any excess power at your current speed (RPMs locked to speed) is transferred to the battery.

However, going up a somewhat steep incline when the battery is drained results in high revs (even at slower speeds) which I think means it is switching to serial mode and running the generator heavily. My current strategy is to switch to Safe mode with the battery half full so as to have the reserve to go up hills in parallel mode. Haven't done enough towing yet in this mode to reach a conclusion as to whether it works better.

Exactly, when you exhaust your battery the engine goes in Series and running the generator heavily cause it can operate in higher RPMs to provide requested power and it is happening because you didn't use Charge on time to keep up the battery.

So it is not Charge but the lack of using it that place you in a position where the engine works as hard as possible in Series in order to compensate for the missing battery power. In top of that with 10% additional energy conversion losses, cause it is in Series right.

Charge is what the vehicle is doing automatically when out of battery anyway, it should be used on the highway when the vehicle can be in parallel and especially in advance before big power demand.
It won't consume more if at the end of the trip one arrive with empty battery.

 

[BobK]

Don't you realize that what you are describing is the vehicle goes in to Charge mode automatically once your battery is exhausted? Exactly the same is happening when you press Charge. The clutch is engaging and you have direct drive to the front wheels, any excess power at your current speed (RPMs locked to speed) is transferred to the battery.

Exactly, when you exhaust your battery the engine goes in Series and running the generator heavily cause it can operate in higher RPMs to provide requested power and it is happening because you didn't use Charge on time to keep up the battery.

So it is not Charge but the lack of using it that place you in a position where the engine works as hard as possible in Series in order to compensate for the missing battery power. In top of that with 10% additional energy conversion losses, cause it is in Series right.

Charge is what the vehicle is doing automatically when out of battery anyway, it should be used on the highway when the vehicle can be in parallel and especially in advance before big power demand.
It won't consume more if at the end of the trip one arrive with empty battery.

In my experience so far, running the vehicle in Charge mode while towing results in more high revving than running it in Normal. But I agree with you that running the battery to exhaustion is not the answer either, so that is why I am experimenting with Safe mode - but not sure if this really is any different under load. Maybe I should be switching from Charge to Normal whenever I hit a hill to encourage it to stay in parallel mode for the extra loading?
When not towing and I let the battery run down to zero at highway speeds, I do find a difference between what you call "going into Charge mode automatically" and when I specifically select Charge mode. Unlike what you are suggesting, it seems to rev a bit higher (and consume more gas) when I select Charge mode. Also, while it takes a longer than I think it should, I do see some charge accumulating on the battery over time, but not if I leave it in Normal. I think when the battery is exhausted it is more like automatically going into Safe mode, but bottoming out and switching to Series running more often.
I do agree with you that keeping some charge in the battery at all times to allow more lee way for maximimum Parallel running is probably the best way to travel.

 

[Ken Butcher]

This discussion is very interesting. Am I wrong in (generally) running the car in Normal mode and letting the computer make the decision when to switch between series and parallel?

 

[AndyInOz]

I just get in mine and drive.

Seems to have worked fine so far.

I usually only use charge mode to make the engine run periodically to keep everything lubricated.

(Not counting yesterday, where I ran it for an entire way out to the grocery store, because the car hadn't charged up.)

 

[greendwarf]

Of course it does. It also reduces the life span of the car. The harder the engine works, the less it will last. It is no different than a human being. If you burn your candle at both ends, get little sleep, smoke a lot...you will die earlier. That is generally true..but not always. That is why we do not like to buy second hand cars. How do we know if it has been driven mostly at 40 mph or it has been raved at 80 mph. No way of knowing but we would choose the car that was driven carefully at 40mph instead of 80mph most of its life without towing. Fair enough you may be able to check how many miles it has done, or whether it had been involved in an accident. You cannot however check how it was driven, and whether it was towing most of its life.

So what? - it's not a person but a machine that is designed to serve a range of customer needs. If one person's use wears it out sooner than by somebody else, it has still achieved its purpose!

 

[kpetrov]

In my experience so far, running the vehicle in Charge mode while towing results in more high revving than running it in Normal. But I agree with you that running the battery to exhaustion is not the answer either, so that is why I am experimenting with Safe mode - but not sure if this really is any different under load. Maybe I should be switching from Charge to Normal whenever I hit a hill to encourage it to stay in parallel mode for the extra loading?

There is some misunderstanding here... switching from Charge to Normal won't encourage it to stay in parallel mode. Exactly the opposite, it will go in to full electric propulsion mode. Since towing and climbing it will continue running the engine (big power demand) but in principle switching to Normal mean use the battery only until flat.
You should switch to Normal once you start descending.

When not towing and I let the battery run down to zero at highway speeds, I do find a difference between what you call "going into Charge mode automatically" and when I specifically select Charge mode. Unlike what you are suggesting, it seems to rev a bit higher (and consume more gas) when I select Charge mode. Also, while it takes a longer than I think it should, I do see some charge accumulating on the battery over time, but not if I leave it in Normal. I think when the battery is exhausted it is more like automatically going into Safe mode, but bottoming out and switching to Series running more often.
I do agree with you that keeping some charge in the battery at all times to allow more lee way for maximimum Parallel running is probably the best way to travel.

Lets clarify something first: (everybody knows it but for the discussion)
The engine can operate in 2 modes only Series (generator only) and Parallel (locked to front wheels and generator simultaneously over 65km/h only) What I meant by going into Charge mode automatically is the engine working. Once the engine is working it is charging the battery as well.

Whether one select Normal, Save or Charge the engine can work only in those 2 modes.
Normal will use the battery first and start oscillating the engine on and off at lowest battery charge.
Save will do the same start oscillating the engine on and off but at desired (the moment Save is pressed) battery level.
Charge will keep the engine on until battery is 80% charged or until deselected.

No matter what mode one select the engine will work once out of battery range. Every scientific principle and article will say that Parallel mode is more efficient than Series, otherwise nobody will spend money complicating the vehicle for nothing.
The main efficiency goal will be to use the engine in Parallel mode only - speeds 65km/h and over. Using Save and Charge play a big role in that strategy.
With Charge mode I find it much easier to control my battery SoC and it keeps the vehicle in Parallel mode consistently.
With Save not so much, it stays in Series a lot.

Another misconception is that revving higher means worse efficiency in hybrid systems. It has an battery to dump energy and the engine most efficient work zone is not in low rpms.
Check Brake Specific Fuel Consumption in hybrid systems https://x-engineer.org/brake-specific-fuel-consumption-bsfc/

Another way of minimizing the brake specific fuel consumption is by shifting the engine load into a more efficient area while maintaining the same engine speed. This control strategy is only possible in hybrid electric vehicles (HEV), where engine excess torque can be used to generate electrical energy and charge the battery.


In the example above, let’s assume that vehicle is moving at a constant speed, in a fixed gear. The vehicle speed translates in a point of engine torque (100 Nm) and speed (2500 rpm). The engine efficiency in this operating point, 455 g/kWh, is far from optimal. By increasing the engine torque to 250 Nm we decrease the brake specific fuel consumption to 320 g/kWh. The excess torque (150 Nm) will be compensated by the electric machine (-150 Nm) which will run in generator mode and produce electrical energy.


In vehicle with automatic transmissions, the BSFC map is used as a reference to calculate the shift lines for best fuel efficiency. In hybrid electric vehicles, the BSFC map is used in Energy Management strategies to calculate the torque split between engine and electric machine for best fuel efficiency.