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Regenerative Braking


gillyallan
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Sorry yet another question from me. ...I need to know all about my car lol.

Does it have regenerative braking ? 14 plate 1.0 eco titanium. Im sure it said on etis site that it did, but can't get site to work just now. ..java error.

If it does. .what does it actually do ?

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No it doesn't have regenerative braking, its only found in electric of hybrid vehicles it uses the energy created from breaking (which is usually wasted) to help charge the battery in the car :)

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I wonder if it does in some small sense of the word (especially if it's on etis), to keep the charge of the battery topped up for the stop start system?

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That's good point would make sense specially for stop start if it isn't on there they should add it to the line up of cars with stop start feature

Sent from my iPhone using Ford OC

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Ok got etis working and definitely says it.

With Hill Launch Assist

Brake System - Regenerative

My Key

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Trying to google this throws up more mystery. Im finding reference to it possibly being a smart alternator. Under normal drive acceleration it disconnects but under coasting and braking it hooks back up again to charge the battery.

Guess I need to hope a ford mechanic is on here for the story on this.

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Take it nobody really knows what's lurking beneath then ?

I think the regenerative braking system is charging a lithium battery possibly which runs the start stop system but I've googled till my fingers bled and is hard to find anything on it.

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Take it nobody really knows what's lurking beneath then ?

I think the regenerative braking system is charging a lithium battery possibly which runs the start stop system but I've googled till my fingers bled and is hard to find anything on it.

This was on a US site about it "You also receive what's romanticized as a regenerative braking system, but is actually a smart alternator designed to take advantage of deceleration moments to charge the 12-volt battery and not drag on the engine too much when accelerating or cruising"

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As far as i am aware regular cars like a 2014 Fiesta Ecoboost do not have "proper" regenerative braking

Electric or hybrid vehicles often have regenerative braking where an electric motor connected to the wheels acts as a generator in certain circumstances, (eg, when the throttle is lifted off, downhill, decelerating etc ) controlled by an ECU, to help recover some of the energy (instead of turning the momentum into heat by using the brakes, wasting it, or in conjunction with the brakes

if there is a system using the existing alternator it will not be as effective as a proper regenerative system and is a bit "basic" - although adding a generator to the wheels would add cost, weight and complexity to a non- hybrid vehicle (ive just read daves post) - personally i would not define a "smart alternator" system as regenerative braking, in my opinion

2014 F1 cars have regenerative braking, as well as other "energy recovery systems" like a generator that harnesses power from the exhaust (like a turbo turbine connected to an alternator) - it is so efficient a wastegate is not nessesary

Some recent non-hybrid cars like BMWs have advanced energy saving/ recovery systems or paradigms (marketed as efficientdynamics")

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Im quite surprised this info isn't out there from a technical perspective. Did it only come in on 2014? There isn't even a mention of it in the fiesta brochure and you'd think they would promote this as a jargon selling point.

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Im quite surprised this info isn't out there from a technical perspective. Did it only come in on 2014? There isn't even a mention of it in the fiesta brochure and you'd think they would promote this as a jargon selling point.

Its not "proper" regenerative braking, and the effect is realatively insignificant

its just basically the same as any other car on the furum that charges the battery from the alternator when the engine is running when the clutch is engaged in gear on the overrun going downhill - so everyone has "regenerative braking" they don't, and you don't really, though

"proper" regenerative braking -

Here is the Toyota Prius, from 1997 (and regenerative braking probably goes much further back than that) -

http://www.autozine.org/Archive/Toyota/classic/Prius.html

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This is what Tech Radar says it does:

The new Ford Fiesta also comes equipped with what Ford is calling
"smart regenerative charging". Before you go thinking that means the
Fiesta is some sort of hybrid or electric car, think again. Instead,
it's an intelligent system of control for charging the car's battery.

Previously,
the alternator was permanently hooked up to the engine when running.
Here the Fiesta only engages the alternator when you're coasting,
slowing down, or idling, which reduces wear and tear on the engine and
other components in the system

http://www.techradar.com/news/car-tech/10-tech-tastic-features-inside-the-new-ford-fiesta-2012-1116488/2#articleContent

Jim

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Hi

According to ETIS, my November 2013 Fiesta Titanium also has regenerative braking, albeit at a basic level:

With Hill Launch Assist

Braking System - Regenerative

and I reckon that it does have something to do with the 'stop/start' system and charging the 12 volt battery and the extract from a US website posted by BigDaveZS125 above appears to have nailed it for me.

My car also has "My Key" but that's not mentioned on ETIS.

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My key is mentioned on my etis.

Ok..now to follow this on. If it's the alternator connecting and disconnecting. How does that work? Does the alternator physically move ? Or does the belt still continually run but inside it some sort of gearing move?

I appear to be the only person fascinated by this with everyone else dismissing it as any other car.

I don't mean that in a bad way. Maybe I am looking into it too much.

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My key is mentioned on my etis.

Ok..now to follow this on. If it's the alternator connecting and disconnecting. How does that work? Does the alternator physically move ? Or does the belt still continually run but inside it some sort of gearing move?

I appear to be the only person fascinated by this with everyone else dismissing it as any other car.

I don't mean that in a bad way. Maybe I am looking into it too much.

Manufacturers are looking for ways to increase the efficiency of their cars

On a conventional system, the alternator is connected directly to the crank via pullys and a belt

Its simple/ cheap, but, its always connected. when the engine is running, the alternator is running, when the engine is turnong slowly, the alternator turns slowly, when the engine runs fast, the alternator runs fast when the engine accelerates, the alternator accelerates - its proportional to the engine speed

There are several problems with that - 1st of all the alternator soaks up power, often when its not required (like when the battery if fully charged) the alternator adds rotating mass to the drivtrain, that has to be accelerated with the enging, through the power band

the altermator spins slowly when the engine runs slowly, so it does not have as high an output at lower revs, and may not be charging the battery as efficiently (or quickly) as it would at highr revs

Freewheel -

Some systems have a simple freewheel (like the freewheel on a push bike) so the alternator is only accelerated (not decelerated) - this does 3 things, firstly, when the enging decelerates, the alternator keeps spinning, (keeping the alternator producing power a little later) and increasing efficiency (apparently by 1%) it smoothes out the power pulses of the engine in the aux belt reducing wear and NVH

"On demand" clutch -

there is a (simple, electromagnetic) clutch added to the alternator, when the battery needs charging, the clutch engages, when its charged, it disengages (disconnecting the alternator) this way the engine does not need to spin the alternator when its not needed, increasing performance, economy and efficiency

variable drive -

the alternator is connected to the engine via a variable drive - (eg, cones and belts) so at lower revs the alternator rons faster than a "direct" drive and slower at higher engine revs, this may be simply controlled by engine revs or more sophisticated (on bemand)

ECU contlolled clutch

no it does not sound as good as "regenerative braking " - the alternator is connected to the engine via an electric clutch, that is controlled by the ECU

the battery voltage, alternator output, engine speed and throttle position (and lots of other things) is monitored by the ECU, it decides when the alternator is engaged/ disengaged, it can be mapped/ programmed / updated here is how it might be set up -

When the engine is 1st started, it stays engauged untill the battery reaches a certain voltage, or is fully charged, it may disengauge - if the voltage drops below a certain threshhold, it may engauge the alternator regardless of its more advanced functions (below) to keep the battery charged, it may anticipate demand and respond to extra (electrical)

When you accelerate hard, the alternator may disengage (so the engine revs faster through the band/ increases power to the wheels, so it does not need to turn the mass of the alternator and it does not soak up power)

When you lift your foot off the throttle, or "coast" downhill, the alternator engages, to charge the battery as you are decelerating anyway, if you are "crouising" (steady throttle) the alternator may be engaged or disengaged, depending on electrical demand but it may instantly engage if you decelerate, or disengage if you accelerate

I guess a typical alternator uses 3-5 Hp, does not soud much but is noticable, especially on smaller engined, lower powered or high-revving engines, so it makes a small but noticable difference to performance (acceleration) (engaged vs disengaged)

the alternator does not heat up so much, the whole system is more efficient and the alternator/ belt pulleys do not wear out as quich (and NVH is improved)

A higher-capacity alternator could be specified so the battery charges faster and the entire electrical system has more potential (for extras/ goodies) without impacting efficiency/ economy significantly

it is probably a fixed speed (proportional to the engine) but with the electronically controlled clutch, the alternator could be geared higher so it is more efficient (the alternator spins faster and has a higher output ) at lower revs/ engine speeds but disengages at high revs/ engine speeds (which is in line with the paradigm as if you were revving the engine hard you would want max power to the wheels and the alternator disengaged anyway) even running it at higher speeds it will probably last longer (as its not always connected) - on a regular (fixed) system.the max engine revs are usually matched to the max alternator revs

Reducing the electrical consumption ( eg- reducing the electrical usage by not using things or reducing it by replacing incandecsent bulbs with LEDs etc) would help improve economy (slightly) by the alternator being on (engauged) less, as well as adding a solar panel would have the same effect

in the future the alternator could be removed completely, being replaced by an (electrical) "energy recovery system" (recovering waste exhaust output) suppllemeted by high output solar panels and lightweight hgh-capacity batteries (even in "regular" cars)

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Wow that's a massive explanation. Thanks. I didn't realise something as small as the alternator would actually consume so much power from the engine. Almost dismissing it as the engine wouldn't even notice it being there. I guess that's the same principle though of AC and why they tell you it uses more fuel when on

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Wow that's a massive explanation. Thanks. I didn't realise something as small as the alternator would actually consume so much power from the engine. Almost dismissing it as the engine wouldn't even notice it being there. I guess that's the same principle though of AC and why they tell you it uses more fuel when on

I had an old Nissan (non turbo) diesel,(2.0L) it was quite a slow car, i was driving along the road one day and there was a strage noise and the car suddenly picked up speed - the AUX belt had snapped - (it drove the AC and alternator) the difference it made was surprising - the engine was a lot livlier, and revved batter/ faster, i ran it like that for a few days, keeping charging the battery, untill i replaced the belt - then it was slow again - it stuck in my memory though

My AC never worked properly in my Mondeo, so instead of getting it fixed i decided to rip it out to save weight, (would only use it for 2 months of the year, and i have the benifits of not having it the other 10 months) it was a lot of hassle finding the right belt, and changing it, the shorter bet is a lot more reliable than the (troublesome, rattly) stock belt, the weight of the (always rotating) AC pully is about 1kg, its like taking 1kg off the flywheel - the pump, and other gubbins came to 11kgs

The engine did not seem as quicker as i had hoped, but it was a slight/ noticable improvement (it has a lot of power/ torque) the steering felt quicker, and the car turned in better (by a surprising amount)

11kgs does not sound like much, but it adds up, and along with some other "minor " wieght saving, 150kgs off, that makes it about the weight of a focus, - the reduced weight and increased power makes it about the same power to weight ratio as an ST-TDCI with 200Hp

the 19kg battery was replaced 1sy with a 16kg one then a 12kg one, the much smaller battery went all through the last 2 winters no problem, (the central locking has been disconnected and just about all the bulbs bar the headlights, inside and out, replaced with LEDs,)

The mechanical waterpump was replaced by an electronically-controlled electric one - the mechanical one is supposed to soak up power, in fact they replace them even on 1000hp drag racers (though they may be looking for any improvement, however small) - the electric waterpumpworks on demand and reduces parasitic load (like the advanced alternator/ control) so increases efficiency

I considered removing the alternator altogether, running the electrics off a bank of batteries and fed by a solar panel

, the extra weight of the batteries and large solar panel(s) might ofset the advantages

it would probably be enough in the summer but i would probably need to keep charging the batteries in the winter, a bit impractical/ inconvinient

I figured out (when i was writing that last post) how to run an alternator clutch off nicroswitches on the throttle pedal, the alternator could disengauge at full throttle - i could hook up an AC clutch - it would be similar idea your system (a simpler version)

its got me thinking......

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Wow that's a massive explanation. Thanks. I didn't realise something as small as the alternator would actually consume so much power from the engine. Almost dismissing it as the engine wouldn't even notice it being there. I guess that's the same principle though of AC and why they tell you it uses more fuel when on

I did a bit more research and have foond that a typical 700w alternator uses 2 to 4 Hp, but with the belt bearings and alternator fan the total power loss could be as much as 15Hp at higher revs (eg 7000rpm) (seemed more like 15hp difference than 4hp in my experiance of the nissan) if this is true then the "smart" control of the alternator could make a signifacant difference

on my car-

There is a lot of other stuff running off the engine via belts (ac, power steering, oil pump, water pump, ) as well as the alternator now ive ditched the Ac and i have an electric waterpump, there is a mechanical brake servo pump that could be converted to electric (an "on demand" system) - ive ordered another brake servo pump to look at how i can modify it

As the power steering no longer shares the same drive pully as the waterpump, i could disconnect the power seeering belt on drag racing days or dyno runs (a bit iof a cheat really) it will be interesting to see if it makes a difference (2 dyno runs - one with power steering connected, one without)

With all that gubbins being driven off the engine via belts (soaking up power/ wasting fuel) its not surprising manufacturers are looking at ways to increase efficiency ("smart" alternator control, electric waterpump(vw golf)) - modders tuners gave been doing similar for years - (eg underdrive pullys)

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Using a bluetooth OBD2 scanner and the appropriate software you can see the battery voltage jump up to around 14 volts when you put your foot on the brake... So an alternator that knows when to engage and disengage seems to be what they've done.

Sent from my iPad using Ford OC

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  • 3 months later...

You know I cant actually see how this works. The alternator is running all the time, charging voltage is up at 14V or so when your driving so the alternator is delivering charge, so it will do the same as you go into overrun. Is there generators on the wheels to recover this energy?

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  • 1 year later...

Etis reports my car as - Brake System - Regenerative .   The stop start system still doesn't work though. :-(

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  • 2 years later...

The alternator on the focus is controlled by a ecu if you look at the alternator drive there is a rubber cushion ring connecting the alternator to the pulley .When cold after starting the ecu will decided on battery temp air temp and engine temp and charge at anything over 14.4 volts as everything warms up charging rate will go to 14.2 volts I assume on the new Focus when accelerating the alternator stops charging releasing power when braking or crusing down hill it will fully charge as this doesn't use any fuel hence the free power and Ford's take on regenerative braking

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