MB37

The incorporation of regenerative (energy return to supply) and rheostatic (heat dissipation) braking are great. My question is when does the system actually uses mechanical braking (brake pads and rotors) when you step on the brake pedal?
1. Does it actually depend on the regen mode, and if so, at what limit?
2. Voltage regen limit and / or g-force activation?
3. What is the best (optimal) condition of braking that the EQS will not use or will least likely use the mechanical brake, and in which braking condition will the EQS use the most regen and rheostatic braking?

I've test driven and drove like a granny when it comes to braking for a week in an attempt to experiment. Yet, I still get black dusting on my rims. I've turned off nanny such as the LKA (lane keep assist). I don't think it's road dust because it's quite black.

c4004matic

It always uses "blended" braking. The regen simply lowers how much work the mechanical brakes do. If you step on the brake the hydraulic brakes are used.

MB37

That sucks. I guess I will just continue to switch between the different regen to brake if my foot is lazy.

QuadBenz

This is 100% false. Stepping on the brake pedal will always use regen, regardless of drive mode, unless you are braking strongly and the physical brakes are needed.

You can feel the transition from regen brakes to physical brakes through the pedal very clearly (on the 2023s at least - this should be fixed 2024+). It takes substantial amount of pedal travel and force to start dipping into the physical brakes. 99% of the time, you are using regen when you're using the brake pedal.

W205C43PFL

If brake dust is your only concern OP, ceramic coating the wheels might help.

QuadBenz

"Mercedes electric vehicles (EVs) employ an advanced regenerative braking system that actively recovers energy both when the driver steps off the accelerator and when they press the brake pedal. Initially, when the driver lightly presses the brake pedal or releases the accelerator, the regenerative braking system activates to slow down the vehicle while converting the kinetic energy back into electrical energy for the battery. The physical brakes are engaged more significantly only when stronger braking force is needed, such as during quick or emergency stops."

Like I said earlier, Mercedes EVs almost always use regen and rarely ever use the physical brakes. Pressing the brake pedal always activates regen braking regardless of drive mode or regen mode. Fact.

ScottC2

And one interesting way you can view the effect of this regeneration real-time is by looking at the curved "% Charge" LED readout at the bottom of the Power meter (when the driver display is in "Classic" mode).

c4004matic

The second you press the brake in any mode the hydraulic brakes are used. There is no transition what changes us the proportion of e braking force and hydraulic force. In strong regen, the instant you release the accelerator full regenerative force is present, once you touch the brake pedal the hydraulic brakes join the "effort" in proportion to the pedal effort. The whole Idea if one pedal driving is not to use the hydraulic brakes at all.
You train yourself to stop by simply modulating the accelerator. On normal, there is also regen when you lift up, but it's only enough to mimic a normal ICE deceleration. On no regen, regen is only activated when you press the brake thus on lift off, the car simply coasts like an ICE engine on neutral gear. In efect the different modes are truely more a variation of the accelerator behaivior than the brake itself.
Thats entirely up to you! I use full regen or nomal in city driving. I use auto on the highway. On haighway dreiving saves more energy than regenerating since you rarely use the brakes anyway.

ScottC2

What is the optimal regen mode? That is the most perplexing question of my EQE SUV ownership. I've read many well-explained and well-justified posts on this forum, but have concluded each must decide for himself which mode is best. For me, I continue to like D-Auto (Intelligent Regen) for local driving. Takes a awhile to get used to it, yes.
I read the entire EQE SUV instruction manual that came with my car, in Swedish. A struggle for me, as my native language is English. My local dealer finally provided me with an English (European) version of the manual, so I'm reading it again...with a much better level of comprehension. I noted this: That when you press the button to "maximize range" the car, among other things, goes to D-Auto mode. So this tells me that MB, at least, thinks D-Auto is the best way to conserve battery and maximize range.

c4004matic

In the highway coasting is more efficient than regen since you rarely use the brakes. In city driving regen is more efficient since you use the brakes all the time. That why "auto" uses bith and is considered the most efficient of all the modes. The issue I have with auto in city driving that since the setting changes on its own accord I can't pedict how the system is going to react when I press the brake. There is the green light on the HUD that tells you, but that's an extra step that seems to unnatural to braking.

ScottC2

l totally agree. I guess I have gotten used to hovering my foot over the brake pedal because I can’t be 100% certain about what it’s going to do. But fortunately, it doesn’t bother me.

c4004matic

Its all about choices! In the beginning I didn't like strong regen. It grew on me once I learned how to use it appropriately. In city driving I rarely use the brake anymore.

hlothery

I drive much of the time in heavy city traffic. I use strong regen (and the OPD is provides) almost daily, when I am in heavy traffic. When it thins out, I click to normal regen for the rest of my driving. I love OPD, and really miss it when in traffic driving my wifes AMG GLE. I have never warmed to intelligent regen.....just seems so iffy to me, I can't abide by it. But, to each his own. Mainly, I love this marvelous vehicle!

MB37

I understand what's the "best" way to maximize the regen and rheostatic braking based on what condition. My question is that even when I do that, I still get brake dust. Why? I've driven in a week where I never had to touch the brake pedal to come to a stop (maybe once or twice max), and I still get brake dust. I do know that the car does apply the hydraulic brake when it is at a complete stop in any regen model even if you don't touch the brake pedal (except no regen mode).

If the theory is that the hydraulic friction brakes are not used unless the brake pedal is press beyond the strong regen or normal regen automated press, then what is causing the brake dust in a week's driving when I've only pressed on the brake pedal about once or twice? LKA is off. No brake squeals. Amount of brake dust is the same for all 4 rims. A nice thin film of brake dust is seen with a finger swipe. During the week of testing, I use strong regen in city, and normal or no regen on freeway. This is about a span of 200 miles city and freeway driving traffic and no traffic segments.

MB37

Thanks. I've used the ceramic spray-on /wipe off from Griot's Garage. It works well. Dusting is reduced as seen on my 7er.

lkfoster

My old Audi e-tron would not use Regen braking the first couple times when braking. I imagine that it was to keep the rotors clean. You could see it in the power/Regen gauge.

emailforbrett

I come from a Tesla Plaid to this AMG EQS. I don’t think the EQS has the regen efficiency of the Tesla. My Tesla used zero brake pads and all regen unless I pressed on the brake pedal. That was evident by zero brake dust over two years of ownership. My EQS, on the other hand, piles on the brake dust daily. I never touch the brake pedal in the EQS. I think Mercedes just doesn’t have the same level of regen ability as Tesla.

I think overall, Tesla is far ahead in all things drivetrain and charging. Mercedes wins in every other category. I don’t miss my Tesla one bit, though it does suck to have to scrub brake dust now. I thought those days were over.

MB37

It's comforting to know, I'm not alone. It's a easy clean up of the spill with ceramic spray coating on the rims, but, man, the leak sucks when you're really not using the brake pedal and still have to clean up.

MB37

I, too, read somewhere that the Germans keep the rotors clean with occasional rotor and pad contacts. In the EQS in strong regen, the brake pedal is automatically depressed to a certain degree, so it is hard to tell if hydraulic braking is used or not. On the dash, the charge numbers jump immediately when you let off the accelerator pedal. If any master MB tech out there knows, please share the information. My curiosity is turning into a itchy rash.

QuadBenz

When you let off the accelerator in strong regen and the brake pedal depresses, if you use the Classic speedometer setup, you'll see that it only regens to about 80% capacity. If you notice, you can press the pedal and there's a tiny amount of distance that it travels easily before it starts to get firmer. That small distance before the point where it firms up is the rest of your regen power. Anything beyond this is then dipping into physical brakes.

In addition, I don't think regen is ever used in reverse, I believe it's physical brakes only.

QuadBenz

As an owner of multiple EVs, including a few Teslas, and as someone who follows the auto industry closely, Tesla is one of the least competitive manufacturers today when it comes to charging performance. They have on paper very high charge rates (250 peak advertised) but that is only held for a few percent.

In reality and during real world road trips and scenarios, all of our other EVs completely outperform the Teslas. It's no comparison.

Out of all of the EVs we have/had, the actual best charging one has been the Porsche Taycan, followed by the EQS. The Taycan and EQS have very flat charge curves and pull strongly across the whole charge. The EQS can pull incredibly high speeds at high states of charge above 80% whereas Teslas basically trickle charge at that point.

Lastly, the EQS has consistent power from 100% all the way down to 3% in normal weather or 13% in extremely cold weather. Teslas have the most power at 100% and the amount of power available decreases with battery percentage. The lower your battery, the less power you have. That is truly unacceptable and I'm glad Mercedes has got that right.

emailforbrett

I’m gonna have to disagree from the standpoint of owning two previous Teslas. You are correct about battery discharge performance (horsepower) vs battery state of charge with all Teslas, except for the Refresh Model S. The horsepower degradation that came with battery state of charge loss was eliminated with the Refresh S. Same thing with torque curve staying stable beyond 80 mph. That was a problem for previous Model S, but fixed in the Refresh.

Home charging with a L2 charger is slower with the Mercedes Wallbox, as compared to the Plaid connected to the Tesla Wallconnector. On a 60A circuit, the Mercedes tops out at 9.6 kw vs the Tesla 11.5 kw.

DC charging is seemless with the Tesla, not so much with the Mercedes. With the Tesla you plug and go at any of their Superchargers. It just works. With the Mercedes, the “Mercedes” branded chargers are run by ChargePoint and have continual issues. Using the third party to do the handshake fails often. I end up having to use my phone to make the handshake. It’s not seamless.

Agian, I don’t miss Tesla at all. They do performance and charging right, but that’s about it.

c4004matic

Might be that by using mostly regen it might make the prolem even worse. Its vitually impossible to use one oedal drive 100% of the time. Thus, when you do use the friction brakes they are "dirtier" than they would otherwise be.
Just a theory.

LAZARU5

I get very little brake dust since I toggled Lane Keep Assist off. I drive with regen mode in Normal or No Recuperation when I remember to turn off Normal.

ScottC2

I don't doubt what you say, however I find myself wondering just what is it about LKA that requires the use of brakes. How does it work? It certainly seems "not-green" to be using brakes.
I have had Steering Assist and Lane Keeping Assist on for my EQE SUV since day one and must say that I have not noticed any brake dust yet. But we only have about 2500 km on it.
I do know what it looks like, as our Volvo S60 produced a lot of it...and that car had hardly any assistants. Certainly not Steering or Lane Keeping assist.