Regen Vibration

[Wayne-001]

it’s not that simple, Regen breaking creates a lot of Kw’s. Easily peaking at 70-80kw just by letting it off the go pedal in 1-pedal driving at higher speeds.

Notice when your fast charging, above 80-90% SoC the charge rate drops dramatically? Like well under 40kw. This is the issue, with a battery at 99% or 97% the battery just can’t safely absorb energy at a rate of 70kw, so to protect the battery the regen is limited to almost nothing and you rely on the mechanicals brakes to slow down. As your SoC goes down the potential for regen absorption goes up.

temperatures factor into this as well. A very cold or very hot battery will also trigger some protection and limit regen.

I understand your point, although the real battery is really only at 92% when it says charged to 100%.
One point I do not get is that you say you rely on mech braking in this situation, but in 1PD (or OPD) I don't think that engages unless you press on the brake. I generally do not instantly take my foot of the accelerator in 1PD, but are you saying you won't slow down at a high SoC by doing this (and be forced to press the brake)?

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[OH2AZ2OH]

I understand your point, although the real battery is really only at 92% when it says charged to 100%.
One point I do not get is that you say you rely on mech braking in this situation, but in 1PD (or OPD) I don't think that engages unless you press on the brake. I generally do not instantly take my foot of the accelerator in 1PD, but are you saying you won't slow down at a high SoC by doing this (and be forced to press the brake)?

MachEs use hybrid braking, which means the computer controls the braking balance between regen and friction at all times and in all modes. There is no loss of regen braking when using 2PD. The computer uses available regen first, then friction braking as needed and all friction below 5 mph. All mass market EVs run this way *except* Teslas, and even Tesla is switching to hybrid braking. It does sound like at 100% charge, the computer only uses friction braking. If the car is in N, then for sure all braking is friction.

OP may have slightly warped rotors that is not apparent when regen is doing most of the high speed braking work. Corrosion build up on the rotors, which is very common on EVs, can also do this. I noticed a little braking vibration a few weeks ago, but after I did a few stops after switching to N, it was barely noticeable.

 

[MadMatt]

92% to 100% is not accurate. It’s more like 98%-100%. The dashboard percentage is not hiding that much. The last time I charged to 100% I saw the battery at 74kw. This is supposed to be a theoretical 76wk battery with “72kw usable”.

When at a very high SoC on 1 pedal mode the vehicle tries to maintain the same feeling by automatically engaging the brakes vs using the e-motors. Part of the seamless driving experience.

even in non 1P mode, when using the brake pedal it’s only the e-motor doing the braking with regen. Again, at a very high SoC the car switches to physical brakes without the user knowing.

this issue in this thread is that in either mode the brakes don’t get used a lot so all of a sudden you’ve got brake shake in the steering wheel at 98-100% SoC and your first thought is “something wrong with the e-motor!”.

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