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I'm still not exactly sure about this. If you step lightly on the brake are you using your brake pads at all or is the generator slowing the car down? There's no question the car charges rapidly when braking, but is that from friction on the brake pads or from the transmission?

When going down a long steep hill are you better off keeping the brake pressed lightly or shifting to a lower gear? Which will give you the greatest charging recovery? Which will cause the most wear and tear?

The reason I ask is because I begin my commute each day with a 500ft drop in elevation down a 2 mile road. If I light use my brakes, the battery charges to 100% on the decline. If I use the tranny to slow me down the battery only charges to 75%. I'm clearly getting more charging from the brakes.
 

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The only thing that charges with the breaks is the regenerative breaking. Break pads just turn your energy into dust and heat. When you take your foot off the gas you are getting a little regenerative breaking to simulate engine drag. As you put you foot on the break the regenerative breaking increases until the car determines it needs the break pads in order to stop as fast as you want.

So to get the max energy recovery you should lightly break. Downshifting does increase your gear ratio and the simulated engine drag would be higher than if you did not, but the light breaking will give you the max recovery as you have seen on the battery charge.
 

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Lightly braking

The only thing that charges with the breaks is the regenerative breaking. Break pads just turn your energy into dust and heat. When you take your foot off the gas you are getting a little regenerative breaking to simulate engine drag. As you put you foot on the break the regenerative breaking increases until the car determines it needs the break pads in order to stop as fast as you want.

So to get the max energy recovery you should lightly break. Downshifting does increase your gear ratio and the simulated engine drag would be higher than if you did not, but the light breaking will give you the max recovery as you have seen on the battery charge.
This will probably make drivers behind us mad as we are braking way to soon and might cause an accident. It would be OK if when you lightly brake the lights don't come on.
 

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This is one of those things that is different about driving a hybrid car versus a regular car. In a regular car you wouldn't want to ride the brakes all the way down a long hill; you'd want to save the brakes by downshifting. In a hybrid car, as long as you ride the brakes lightly, you're not using the brake pads at all, so you're not going to wear out or overheat your brakes, and you will recover the energy.
 

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This is one of those things that is different about driving a hybrid car versus a regular car. In a regular car you wouldn't want to ride the brakes all the way down a long hill; you'd want to save the brakes by downshifting. In a hybrid car, as long as you ride the brakes lightly, you're not using the brake pads at all, so you're not going to wear out or overheat your brakes, and you will recover the energy.
But aren't your brake lights on when you do this?
 

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Yes, the brake lights are on which could definitely be annoying to someone behind you if you're braking too early.

Thanks for the answers. Good to know I'm avoiding wear on the brake pads.
 

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It would be handy to know when brake energy is going fully into the battery, and when some or all is "wasted" with brake pads. The pads could be used because the braking exceeds capacity of the regenerative system, or because the battery can't take any more charge.

The display shows the energy flow, but not when and if the braking exceeds the amount of possible regeneration.

If the display could be enhanced, I would recommend displaying when brake pads are used beyond regeneration with a red glow inside the graphics of the "tires" on the energy flow display.
Even better, I'd like to see an "engineer mode" display that shows the KW of energy flowing from between battery, wheels, and engine in real time.
 

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Break = broken

Brake = stop the action of...


:00000732:
 

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i'm pretty sure brake pads have nothing to do with regen. braking.
the electric motor spins all the time, when you send powet to it it works a s a motor, when you don't it works as a generator, touching the brakes pretty much does nothing exsept slowing the car down. it is computer the desides to send power to the motor or take power of it. not brake pads.
 

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Sorry to resurrect an old thread, but for those of you who are confident that you regen-brake when you mean to, about how hard are you pushing on the pedal? Just resting your foot on it? Maybe you could give a number from 0-100% on how hard you rest on the brake to regen. Tell me the max pressure that you feel like you can push without initiating the friction brakes.

Is there any other way telling which brakes your using (sound, feel, displays, etc...)?
 

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Any time you're doing > around 10 mph, you can tell when your friction brakes kick in by watching you eco gauge. While slowing down from highway speed, try progressively adding more brake pressure. You'll see the gauge kick up higher when you cross the friction brake threshold.
 

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i'm pretty sure brake pads have nothing to do with regen. braking.
the electric motor spins all the time, when you send powet to it it works a s a motor, when you don't it works as a generator, touching the brakes pretty much does nothing exsept slowing the car down. it is computer the desides to send power to the motor or take power of it. not brake pads.
Sounds right... this is for a Prius but may apply to us as well.

Does the prius' regenerative braking ever wear out? - Yahoo! Answers

Here is Hyundai's Patent. You can read, 2. Description of the Background Art, which give good background information on braking.

Patent US8090515 - Method for controlling regenerative braking in an electric vehicle - Google Patents
 

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Any time you're doing > around 10 mph, you can tell when your friction brakes kick in by watching you eco gauge. While slowing down from highway speed, try progressively adding more brake pressure. You'll see the gauge kick up higher when you cross the friction brake threshold.
I tried this but didn't notice anything change in the Eco gauge even after I started pressing hard. One interesting thing that I noticed, however, is that while going down a hill on cruise control, the Eco gauge went up higher, almost into the red zone, while trying to slow down to maintain my speed. Has anyone else noticed this? It's very interesting to me though because I thought that while on cruise control, it would try to regen the power instead of using friction brakes. Does anyone have an answer for this? Do you know if cruise control uses regen or friction to control speed while going down a hill?
 

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Great question Kayan.
No hills in South Florida but my eco guide does not go up when cc is on and going down a bridge. Maybe it just isnt steep enough.
 

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I tried this but didn't notice anything change in the Eco gauge even after I started pressing hard. One interesting thing that I noticed, however, is that while going down a hill on cruise control, the Eco gauge went up higher, almost into the red zone, while trying to slow down to maintain my speed. Has anyone else noticed this? It's very interesting to me though because I thought that while on cruise control, it would try to regen the power instead of using friction brakes. Does anyone have an answer for this? Do you know if cruise control uses regen or friction to control speed while going down a hill?
When the transmission downshifts and engages engine braking, the eco guide will go up. For example, when slowing down, go into manual mode, and downshift a couple of times, you'll see gauge go up.
 

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Ahhh thats right, I should have known. 58 is correct, the engine does downshift to hold its cc speed but of course applying the brakes would more beneficial due to the charging effect.
If I am not running cc I always release the throttle down a hill / bridge. The car goes into E mode and I coast which maintains speed and charges the batteries. CC is more efficient on a flat surface but not so much with hills.
 
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I have verified the braking effect of eco guide, my best guess is the harder you brake the more energy is directed to recharge the battery pack, since the hsh control unit sees more energy applied thats reflected on the eco guage.
 
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