Energy harvesting using Save mode?

[Vince31]

We drove a long journey today (400 miles) on a mix of motorway, fast A roads, as well as through towns and villages. My plan was to Save battery power for the towns and slow sections but I soon found that the battery was depleted too soon. My question is. ......... Is there a way to harvest the re-gen energy to slowly increase the battery level back up again whilst driving on the fast roads, as the Save function just seems to save the energy you have left and keep it at a constant level until you decide to use it? Ideally, on long downhill streches and slowing down for roundabouts etc Id like to save all the re-generated power for use later on at a time that suits me, rather than use it all up again in the next section of road.

 

[Neverfuel]

We drove a long journey today (400 miles) on a mix of motorway, fast A roads, as well as through towns and villages. My plan was to Save battery power for the towns and slow sections but I soon found that the battery was depleted too soon. My question is. ......... Is there a way to harvest the re-gen energy to slowly increase the battery level back up again whilst driving on the fast roads, as the Save function just seems to save the energy you have left and keep it at a constant level until you decide to use it? Ideally, on long downhill streches and slowing down for roundabouts etc Id like to save all the re-generated power for use later on at a time that suits me, rather than use it all up again in the next section of road.

There is a school of thought that says employing charge, during parallel hybrid driving is good for your mpg. Have a play - then let us know (as I am guessing you have a MY16 Facelift)

 

[jaapv]

That would be the Charge button .
Actually, going down a long incline will recharge the battery to a higher level than set by the Save button. If you disengage and reengage Save in that case the car will retain the higher level.

 

[Vince31]

I understand that the Charge button uses the ICE to replenish the battery, I want to top it up using the re-gen energy only if I can. The dealer told me never to use the Charge button as it will hit my MPG hard, but happy to give it a go in Parallel Hybrid mode the next time I do this journey in Jan to see what difference it will make to the overall MPG/costs. Also going to try re-setting the Saved power level after long downhill stretches by switching it off and then on again to see if this will work. I'll let you know.

 

[anko]

I understand that the Charge button uses the ICE to replenish the battery, I want to top it up using the re-gen energy only if I can. The dealer told me never to use the Charge button as it will hit my MPG hard, but happy to give it a go in Parallel Hybrid mode the next time I do this journey in Jan to see what difference it will make to the overall MPG/costs. Also going to try re-setting the Saved power level after long downhill stretches by switching it off and then on again to see if this will work. I'll let you know.

For MPG, it does not make a difference all all, whether you use Save or Charge. The only difference is that Save mode will turn on and off Charge mode in order to keep SOC between a lower and upper limit (typically 1.5% apart). When using the charge button, you are responsible for controlling the SOC level.

But for what you want, Jaap was right. Disengage and reengage Save mode after a long decline.

 

[HHL]

[/quote]For MPG, it does not make a difference all all, whether you use Save or Charge. The only difference is that Save mode will turn on and off Charge mode in order to keep SOC between a lower and upper limit (typically 1.5% apart). When using the charge button, you are responsible for controlling the SOC level.[/quote]

According to the documentation, the SOC is maintained around 5% of the SOC when the button is pressed in save mode. A similar thing happens in charge mode, however, it will charge to about 86% from any level lower and charge again when level drops below 80%.

And, if one does not press either button, the car will maintain between 25 and 30% while driving.

I presume this is why it never seems to take more than 9 -9.5 kWh when charged from zero indicated EV range.

 

[gwatpe]

I suspect that a driver will get tired of pressing the SAVE mode button in an effort to build the battery level with just REGEN. I get the opportunity to reset the preserved charge level on a particular downhill stretch with almost 400m height drop with a continuous, steep downhill grade. Any other time does not seem practical. As long as the battery shows about 50% on the gauge I just leave the PHEV in SAVE mode while moving. If there is a stop for traffic, turn off save if the ICE is operating. A toggle of the SAVE button is usually enough to reset to a new slightly lower number and keep the ICE OFF when stopped. If the battery gets down to 25% on the gauge, I use CHARGE instead of SAVE to bring the level back up to about 50% on the gauge, and only if parallel mode driving is available. Every drive is different, so adaptability of a driving style is a valuable tool.

 

[anko]

For MPG, it does not make a difference all all, whether you use Save or Charge. The only difference is that Save mode will turn on and off Charge mode in order to keep SOC between a lower and upper limit (typically 1.5% apart). When using the charge button, you are responsible for controlling the SOC level.

According to the documentation, the SOC is maintained around 5% of the SOC when the button is pressed in save mode. A similar thing happens in charge mode, however, it will charge to about 86% from any level lower and charge again when level drops below 80%.

And, if one does not press either button, the car will maintain between 25 and 30% while driving.

Perhaps the documentation is wrong and / or incomplete?

When driving faster than approx. 50 - 60 km/h the engine will normally engage at 31 % and disengage at 32.5%.
When driving slower, the engine will normally engage at 26%. Due to proper planning ahead, I seldom see it stop charging because of reaching the high water mark. But it is definitely not 5% higher.

Values below 26% are possible by "pushing it really hard" while SOC is already low. But in most cases this requires mountain climbing and/or heavy towing. Once I 've tried to run it down below 25% by over and over accelerating from as low as 120 km/h to as high as 170 km/h and pretty much failed:

 

[Carnut]

At the risky of appearing a complete numpty......
Will somebody explain 'parallel hybrid mode & series mode '. In very simple terms svp!
Seen it mentioned in the spagheti junction of a handbook. Does it refer to the actions of the save and charge buttons? Or am I being more stupid than usual?
Thanks.

 

[Neverfuel]

At the risky of appearing a complete numpty......
Will somebody explain 'parallel hybrid mode & series mode '. In very simple terms svp!
Seen it mentioned in the spagheti junction of a handbook. Does it refer to the actions of the save and charge buttons? Or am I being more stupid than usual?
Thanks.

Series hybrid - when the engine runs the generator to power the battery, the wheels are powered by both front and rear electric motors. This happens when the battery State Of Charge (SOC) is low, or extra power is needed during overtaking or towing.

Parallel hybrid - the engine is coupled directly to the front wheels through a single gear. The rear motor drives the rear wheels, any surplus power is used to recharge the battery below certain speeds.

Save mode - will maintain a specific SOC within 5% of when you press the button and the engine will stop and start as required to keep the battery topped up. This mode is generally used at high speeds to save the EV mode for hilly terrain or slow driving round town, later in the journey.

Charge mode - will build the level of the battery up to approx 86%. This is used to ensure that you have enough reserve power for hills, or if towing. Charge mode will run the engine continually, even if you are stopped, and will not switch off until 86% is reached. This will obviously use more fuel than normal. It is believed that a stationary car will use approx 3 litres to charge from minimum up to the highest level it will allow.

 

[jaapv]

Series hybrid is the engine driving the generator to provide the electricity for the motors ( and battery).
Parallel is the engine coupled to the front wheels providing additional mechanical power (and charging the battery) Possible from 60 Kph.

 

[gwatpe]

At the risky of appearing a complete numpty......
Will somebody explain 'parallel hybrid mode & series mode '. In very simple terms svp!
Seen it mentioned in the spagheti junction of a handbook. Does it refer to the actions of the save and charge buttons? Or am I being more stupid than usual?
Thanks.

Series hybrid - when the engine runs the generator to power the battery, the wheels are powered by both front and rear electric motors. This happens when the battery State Of Charge (SOC) is low, or extra power is needed during overtaking or towing.

Parallel hybrid - the engine is coupled directly to the front wheels through a single gear. The rear motor drives the rear wheels, any surplus power is used to recharge the battery below certain speeds.

Save mode - will maintain a specific SOC within 5% of when you press the button and the engine will stop and start as required to keep the battery topped up. This mode is generally used at high speeds to save the EV mode for hilly terrain or slow driving round town, later in the journey.

Charge mode - will build the level of the battery up to approx 86%. This is used to ensure that you have enough reserve power for hills, or if towing. Charge mode will run the engine continually, even if you are stopped, and will not switch off until 86% is reached. This will obviously use more fuel than normal. It is believed that a stationary car will use approx 3 litres to charge from minimum up to the highest level it will allow.

My PHEV has been in CHARGE mode, with a battery level lower than 50% indicated on the gauge, and the ICE has turned off for a period while driving. Caught me a bit by surprise. The operations do not seem to be that rigid, and sometimes the car does unexpected things. The above is generally what happens.

 

[zzcoopej]

My PHEV has been in CHARGE mode, with a battery level lower than 50% indicated on the gauge, and the ICE has turned off for a period while driving.

I could imagine when on a very steep descent, regen using the brake pedal could get to the point where it alone puts in the max (60kW?, I think I've seen >40kW on my App, so its definitely more than the 30kW regen limit show on the [-30 to +60] MMCS map split screen bar?) that the battery can handle, maybe leaving no need for the ICE to be running?

 

[maby]

...

My PHEV has been in CHARGE mode, with a battery level lower than 50% indicated on the gauge, and the ICE has turned off for a period while driving. Caught me a bit by surprise. The operations do not seem to be that rigid, and sometimes the car does unexpected things. The above is generally what happens.

Ours will also run in charge mode all the way up to 100% charged. I have tried leaving it in charge mode while driving around town and never seen the engine shut off.

 

[gwatpe]

I have also had the battery recharged to 100% in CHARGE mode. The instance I mentioned was not on any steep downhill grade with big REGEN. The control systems in the PHEV do seem to be affected by glitches and the ICE shutting down my still have been a response to a glitch.

The steep hill I regularly traverse, can regularly increase SOC 7-8%, about 2bars on the gauge.

 

[anko]

I have also had the battery recharged to 100% in CHARGE mode. The instance I mentioned was not on any steep downhill grade with big REGEN. The control systems in the PHEV do seem to be affected by glitches and the ICE shutting down my still have been a response to a glitch.

Glitches in the PHEV control statement? That is quite a statement you make there. The car has a reason to temporarily stop the engine, even though Charge mode was selected. We do not understand why it would do that, so it must be a glitch? That seems a bit harsh ...