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Variable regeneration strength

Variable regeneration strength

Does the Tesla range vary the strength of the regeneration based on conditions or GPS? I would want the max regeneration to have the max range and know if you lift heading towards a junction at speed would result in a similar effect to breaking which would charge the battery. If however i am on a fast road and heading towards a large gradient drop, I would know unless I reduce my acceleration that I would go much faster than the speed limit. In an ice car I would fully lift and effectively roll down the gradient. I would assume it I did that in a Tesla that I would rapidly decelerate and lose speed down the hill. My question is - should the car know I am approaching a junction and apply full regeneration but also realise I am on a fast road and don't want to slow so reduce the regeneration

grega | 31. juli 2016

As far as I know, no. Lifting your foot slows the car regardless of why you lifted your foot. The idea is you are in control of the speed accelerating or slowing. Keep the foot pressed slightly down to maintain speed, and if you're going down hill you'd probably lift it off a little to maintain speed down the hill.

I'm not sure if the newer electric brakes (late 2014?) changed regeneration usage at all, simulating regeneration when the battery is full or increasing regeneration when the brakes are pushed, but it probably doesn't affect your question above anyway.

fgaliegue | 01. august 2016

It sounds like a bad idea. Road conditions are by definition unpredictable, so I'd rather the car have predictable behaviour in all situations...

I know, from reading some reviews, that some Mercs and other vehicles have GPS-adaptative auto transmission behaviour, and I have never driven one of these, but it would make me uneasy. Well, maybe driving one would make me change opinions...

Efontana | 01. august 2016

I think you will see the best range in autonomous mode. Variability will trick the human driver.

jordanrichard | 01. august 2016

Ummm, what!!!?

Pay attention to your surrounds/traffic conditions and lift of the accelerator/apply brakes accordingly.

dansplans | 01. august 2016

I think the OP is asking if GPS and other means could be used to automatically engage some level of regenerative braking, for instance in hilly terrain, to take advantage of regenerative opportunities.

To the OP, while it is possible, I don't believe that any manufacturer uses location information to alter the performance of any EV function. As noted above, it could cause issues when the vehicle responds differently than anticipated. It certainly is an interesting idea. Perhaps it can become a regenerative option in the future. It also can be manually achieved by releasing the accelerator at the top of hills, so I doubt it is on the top of any to do list.

nick.thorley | 01. august 2016

As dansplans said, i just wanted variable regen. Coming upto junctions where I would normally have to break then I think regen would be excellent but on a straight fast road that then changes into a big downward gradient then normally i would lift off and coast down - no need to accelerate or brake (even if the brakes are required its just to hold the car from going faster and not to slow. my thought was that if high regeneration was enabled it would be excellent for junctions but would slow too much on the gradient, where you dont want to lift as you would slow too much and if you touch the accelerator to effectively switch off the regen but you dont want to accellerate, just hold speed. I thought having a variable regen would allow you / the car to switch off regen in those gradient situations or maybe switch it to 15% regen (which would be equivalent to light engine breaking.)

dansplans | 01. august 2016

Some EV makers do offer multiple regenerative settings, depending on the operating mode you are using.

bb0tin | 01. august 2016

@nick.thorley
I have multiple settings on my Outlander PHEV. I always set it to the maximum. You very quickly learn how to adjust your accelerator based on the slope etc, just as you do in a car without regenerative braking but lots of engine braking. It is better to have a single maximum setting which you moderate with the accelerator, compared to multiple settings which all behave differently and have to be continuously selected and deselected.

johnse | 02. august 2016

I think the key is that Tesla, and most others, have variable regen. Whether it is controlled by the driver by adjusting how much they release the accelerator, or by how much brake pressure they apply (prior to mechanical braking), you control how much you slow. In my Ford CMax PHEV, the amount of regen when the accelerator is fully released depends on whether you are in Drive or Low. It also has a feature engaged by a button on the shifter which acts as a speed limiter when going downhill--it will use regen to prevent the car accelerating down a hill. It is a very nice feature and can be used with or without cruise control and at very low speeds--even in parking garages.

bb0tin | 02. august 2016

Hill descent can be rolled into cruise control.