USING HILL ASSIST TO HELP BATTERY REGENERATION?

[BWP]

I'm new to the forum...1st post.  I read that using the hill assist during braking enhances the battery charging.  Any input?

 

 

[Bob999]

I posted the following in the "hybrid design question" thread.

 

 

I think that pressing the button on the side of the shifter also engages the ICE for braking while using the brakes gently only engages regenerative braking.

 

Put another way I think you get more regeneration using the brakes alone than using the button -- assuming you don't press the brakes so hard that the friction breaking is engaged.

Edited December 8, 2012 by Bob999

[darrelld]

I posted the following in the "hybrid design question" thread.

 

 

I think that pressing the button on the side of the shifter also engages the ICE for braking while using the brakes gently only engages regenerative braking.

 

Put another way I think you get more regeneration using the brakes alone than using the button -- assuming you don't press the brakes so hard that the friction breaking is engaged.

I think you description is correct, you can confirm this by watching your tach and engaging hill assist during a descent. This is what I have observed.

Edited December 8, 2012 by darrelld

[BWP]

Thanks.  Haven't pulled the tach up yet.  Will have to hit the manual on that one.  

[darrelld]

Thanks.  Haven't pulled the tach up yet.  Will have to hit the manual on that one.  

The tach only exists as part of a My View configuration. I have the Tach and Temp on mine.

[C-MaxJaxon]

The grade assist only engages the ICE going down very steep hills in my experience. On moderate hills, it stays in EV mode and the up arrow shows that the battery is charging.

[MikeB]

Ok, so grade assist will turn on the ICE for engine braking. How about just using 'L' on the transmission selector. Does that just increase regen, or will it trigger the ICE as well? And how does 'L' compare to grade assist, more or less regen?

[darrelld]

The grade assist only engages the ICE going down very steep hills in my experience. On moderate hills, it stays in EV mode and the up arrow shows that the battery is charging.

Thanks, I have only tried this descending interstate bridges (Texas version of a hill).

Edited December 8, 2012 by darrelld

[kechair]

Does anyone know what happens when hill assist is accidentally turned on all the time? My wife came home with the CMax one day - she got out of the car and I got in while the car was still on and I noticed she had hill assist on! Not sure if it was the entire trip or if she triggered it when placing the car in P. I did notice that her trip mpg was only 34mpg (I reset the trip mpg before she left from home - was curious what her driving style would yield in terms of fuel economy).

[Laurel]

I use the grade assist all of the time.  For example if I am going down a 6 block hill and I am traveling at 60 kilometers per hour, it basically keeps me at 60 versus going up to 70 or 75.  I am no car wiz but it does regenerate my battery while doing it.  And I am like your wife and have left it on at least once or twice by accident and I did not see any impact on my mileage--I do pulse and glide and watch my empower and it did not seem to affect me going into EV went I forgot to turn the hill assist off.  But some of the real driving technicians on the forum may shriek in horror at my conclusions LOL.

Edited February 15, 2013 by Laurel

[Jus-A-CMax]

Does anyone know what happens when hill assist is accidentally turned on all the time? My wife came home with the CMax one day - she got out of the car and I got in while the car was still on and I noticed she had hill assist on! Not sure if it was the entire trip or if she triggered it when placing the car in P. I did notice that her trip mpg was only 34mpg (I reset the trip mpg before she left from home - was curious what her driving style would yield in terms of fuel economy).

 

I've done that, I drove from the top of Rocky Peak to Stearn (about 10 miles or thereabouts) and then realised my hill assist was still on and my battery full. Its a smart hill assist and knows when to kick in ICE or use the regen. I have another hill here near my home that I use to regen as soon as I leave the house. You can feel the car slow down on the steep but also the release on the flat - all while the hill assist is on. Pretty smart of Ford. Also, imo, the regen is faster with hill assist and unlike brakes, it does not throw on the brake lights...either way is good as long as you know what you are doing. Your experience will differ  ;) 

Edited February 16, 2013 by Jus-A-CMax

[Roger Eastman]

I read somewhere that when the ICE comes on with Grade Assist, it is not actually running and using fuel, it is just milling and pumping air to assist in slowing the vehicle on fairly steep grades. Can anyone verify this ?

 

I wish we had a direct access to the C-Max Hybrid engineering team to get clarification on things such as this.....

[robertiv]

I'm wondering if anyone has any more insights into this Downhill Assist mode (the switch on the side of the shifter)? In southeast Wisconsin, the hills are quite small, but I find that it can create a significant amount of regen to the battery. I also tend to leave it on much of the time, and it does not seem to hamper FE any. What do other people think? I don't see it being discussed much. 

[drdiesel1]

I'm wondering if anyone has any more insights into this Downhill Assist mode (the switch on the side of the shifter)? In southeast Wisconsin, the hills are quite small, but I find that it can create a significant amount of regen to the battery. I also tend to leave it on much of the time, and it does not seem to hamper FE any. What do other people think? I don't see it being discussed much. 

DHA is designed to keep the vehicle at a set speed. It will regen the battery, but after the battery is full it will activate the ICE in

fuel cut mode to maintain downhill speeds. I use it with my Energi and only had the ICE spin in fuel cut mode 1 time when the HVB was full.

 

I also use it in conjunction with my cruise control. I turn on the DHA, set the speed and activate the CC. It's a great way to run the back roads without doing anything more than steering the car ;)

Edited December 4, 2013 by drdiesel1

[Laurel]

I use it all the time going down hills for regenerating the battery.  I always shut it off after as way back when someone gave the rationale for turning it off when not using it for the designed purpose.  I've searched and can't find the cited reference when the discussion took place many months ago. There was a thread about this when a couple of us forgot and left it on after going down the hills.  I'll keep looking.

[robertiv]

I use it all the time going down hills for regenerating the battery.  I always shut it off after as way back when someone gave the rationale for turning it off when not using it for the designed purpose.  I've searched and can't find the cited reference when the discussion took place many months ago. There was a thread about this when a couple of us forgot and left it on after going down the hills.  I'll keep looking.

 

 

DHA is designed to keep the vehicle at a set speed. It will regen the battery, but after the battery is full it will activate the ICE in

fuel cut mode to maintain downhill speeds. I use it with my Energi and only had the ICE spin in fuel cut mode 1 time when the HVB was full.

 

I also use it in conjunction with my cruise control. I turn on the DHA, set the speed and activate the CC. It's a great way to run the back roads without doing anything more than steering the car ;)

 

Thank you both, drdiesel1 and Laurel. I don't think I've had the ICE spin up, probably because I haven't been on any really significant hills that filled the battery yet. 

 

I've used several search terms to try to find if there's a problem with leaving it on in between downhills, but it doesn't seem to have been discussed very much. Maybe should turn it off each time until I can determine if there's a problem with leaving it on.

[drdiesel1]

Yes, you can leave it on between hills and while driving in areas with hills. Just don't leave it on when you driving flat areas.

[robertiv]

Yes, you can leave it on between hills and while driving in areas with hills. Just don't leave it on when you driving flat areas.

 

OK. Thanks. Do you happen to know the rationale (or where I could find it) for *not* leaving it on? I suppose common sense would say that if it could be left on all the time, they would have just built it that way...

[drdiesel1]

OK. Thanks. Do you happen to know the rationale (or where I could find it) for *not* leaving it on? I suppose common sense would say that if it could be left on all the time, they would have just built it that way...

In the owners manual. It looks like it is designed to turn off Overdrive.

 

D (Drive)

The normal driving position for the best fuel economy.

D (Drive) with Grade Assist

Press the transmission control switch on the side of the gearshift lever to

activate grade assist and cancel overdrive.

Grade assist:

•The grade assist lamp in the instrument cluster is

illuminated.

•Provides additional grade braking with a combination of engine

motoring and high-voltage battery charging to help maintain vehicle

speed when descending a grade.

•As the vehicle determines the amount of engine motoring and

high-voltage battery charging, you may notice the engine speed

increasing and decreasing to help maintain your vehicle speed when

descending a grade.

Press the transmission control switch again to return to normal D

(Drive).

•The grade assist lamp in the instrument cluster will not be illuminated.

L (Low)

• Provides maximum engine braking.

• The transmission may be shifted into L

(Low) at any vehicle speed

Edited December 4, 2013 by drdiesel1

[fotomoto]

Page 209:

 

D (Drive) with Grade Assist

Press the transmission control switch on the side of the gearshift lever to activate grade assist and cancel overdrive.

Grade assist:

• The grade assist lamp in the instrument cluster is illuminated.

• Provides additional grade braking with a combination of engine motoring and high-voltage battery charging to help maintain vehicle speed when descending a grade.

• As the vehicle determines the amount of engine motoring and high-voltage battery charging, you may notice the engine speed increasing and decreasing to help maintain your vehicle speed when descending a grade.

Press the transmission control switch again to return to normal D (Drive).

• The grade assist lamp in the instrument cluster will not be illuminated 

 

I'm not saying it's not there but I cannot find in the manual any stipulations to cancel it.  <shruggs>

[drdiesel1]

 

Page 209:

 

D (Drive) with Grade Assist

Press the transmission control switch on the side of the gearshift lever to activate grade assist and cancel overdrive.

Grade assist:

• The grade assist lamp in the instrument cluster is illuminated.

• Provides additional grade braking with a combination of engine motoring and high-voltage battery charging to help maintain vehicle speed when descending a grade.

• As the vehicle determines the amount of engine motoring and high-voltage battery charging, you may notice the engine speed increasing and decreasing to help maintain your vehicle speed when descending a grade.

Press the transmission control switch again to return to normal D (Drive).

• The grade assist lamp in the instrument cluster will not be illuminated 

 

I'm not saying it's not there but I cannot find in the manual any stipulations to cancel it.  <shruggs>

 

Considering it cancels O/D, I wouldn't drive around with it on, if I'm not in the hills.

[Ryan McEachern]

We have a CVT, so there is no overdrive.

 

The hill assist just uses the regeneration circuit and/or resistance from spinning the engine to hold your speed to whatever it is when you push the button, when the car would otherwise speed up when coasting downhill. It does nothing when the car is not coasting downhill.

 

It is very useful to stop the car from overrunning the speed limit on long downgrades. The rational for turning it off sometimes, is that in some situations it actually makes more sense to allow the car to coast faster downhill, rather than recharging the battery, because you are just going to have to use the energy to get up the hill that is coming on the other side.

[obob]

I used to use it quite a bit but now I often prefer to use the brakes.  Especially after the update, I find the ICE is used too often, so wasted potential regen.  I can do the same hill with the brakes and get more regen and accelerate at the bottom of the hill to save even more.  For super steep long hills where the battery is going to be maxed out anyway, I do still use it.

[ScubaDadMiami]

When I drove to the mountains of the western part of North Carolina, I certainly used it.  Really cool feature!  The downhill runs were long enough to top off the battery, which engaged the ICE in fuel cutoff mode.

 

You will definitely feel it on steep enough downhill grades.  Yes, it makes better sense to turn it off where not needed, because you could be killing some glide that you could be using to keep up to speed.

[drdiesel1]

We have a CVT, so there is no overdrive.

 

 

Tell Ford that.  I didn't write the manual. I just posted the manuals information as it is written ;)

 

As for the CVT not having O/D....... This unit is electronically controlled. :happy feet:

Edited December 5, 2013 by drdiesel1