Slowing down/braking issues while at 100% charge

[mamejunkie]

I just recently noticed this since I changed the max charge to 100% for a trip I took. (Normally set to 85%) Using 1PD and when I lift my feet to slow down or stop, the brakes seems to 'shudder'. Not sure how best to describe it but like someone tapping on the brakes. It is not a smooth deceleration. Also, seems to happen only when the battery is at or near 100%. Like the software is setup to not use regen and op for the friction brakes. Once I drive a few miles and get it down a little, its okay. Tested it a few times and seems to behave the same. Anyone else experience this?

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[RickMachE]

I suspect your car has been sitting, and the brakes are stuck, possibly were wet?

 

[SnBGC]

Have not experienced anything like that with my car.

 

[Ford Motor Company]

I just recently noticed this since I changed the max charge to 100% for a trip I took. (Normally set to 85%) Using 1PD and when I lift my feet to slow down or stop, the brakes seems to 'shudder'. Not sure how best to describe it but like someone tapping on the brakes. It is not a smooth deceleration. Also, seems to happen only when the battery is at or near 100%. Like the software is setup to not use regen and op for the friction brakes. Once I drive a few miles and get it down a little, its okay. Tested it a few times and seems to behave the same. Anyone else experience this?

Hey, good morning! Could you please send over a private message with your VIN and some more information on your Mach-E's braking problems? I would like to see what I can do to assist.

 

[mamejunkie]

 

[mamejunkie]

Hard to tell but on the video I posted above at 8/18/24 sec mark, you can hear the steering wheel shake. That is when I let go of the pedal. The dealer didn't even look at it and just said the software related and it should fix it.

My current fix is just never charge to 100%

 

[hawkeye3point1]

Like the software is setup to not use regen and op for the friction brakes.

A fully charged or very cold HVB does not handle regen current well. Sounds like regen braking is cycling and failing.

 

[Gloff]

Not sure how the Mach-E handles the below situation, but some EVs can't use regen at a full or near full charge.

In certain scenarios a full charge will not let the regen system capture any energy and the pads will be used to stop the vehicle. If you have a very light foot (or use 1 pedal) it's possible your pads haven't been used in some time at any sort of normal temps resulting in some buildup (of rust or other contaminant) on the pad or rotor surface. I'd try a couple stops using medium to hard braking with less than 100% charge and see if you get similar results. If you do, a few braking sessions should resurface the rotor enough to eliminate the shudder.

 

[mamejunkie]

Not sure how the Mach-E handles the below situation, but some EVs can't use regen at a full or near full charge.

In certain scenarios a full charge will not let the regen system capture any energy and the pads will be used to stop the vehicle. If you have a very light foot (or use 1 pedal) it's possible your pads haven't been used in some time at any sort of normal temps resulting in some buildup (of rust or other contaminant) on the pad or rotor surface. I'd try a couple stops using medium to hard braking with less than 100% charge and see if you get similar results. If you do, a few braking sessions should resurface the rotor enough to eliminate the shudder.

That is what my guess are but can't get anyone (officially or unofficially) to confirm it. It ONLY happens when I am at 100%. If I use the brakes manually, it doesn't have to issue so I don't think its the rotor. I am guessing its bad logic (software) when the battery is at 100% and it won't let the Mach-E do the regen so it needs to apply the physical brakes instead. Its just the braking is not smooth.

 

[SnBGC]

My car has full regen when battery charge is 100% displayed.

 

[ridgebackpilot]

In my Tesla Model 3, when I'm close to 100% charge I get a message saying that "Regenerative Braking Temporarily Reduced". I suspect all EVs reduce regen braking when they're close to full charge to ensure they never overcharge the high-voltage battery.

 

[SnBGC]

In my Tesla Model 3, when I'm close to 100% charge I get a message saying that "Regenerative Braking Temporarily Reduced". I suspect all EVs reduce regen braking when they're close to full charge to ensure they never overcharge the high-voltage battery.

The Mach-E is different. Tesla and Ford have very different ideas about battery management.

 

[ridgebackpilot]

The Mach-E is different. Tesla and Ford have very different ideas about battery management.

Care to elaborate? I know Ford builds a bigger buffer into its battery management to prevent drivers running their high-voltage batteries down to zero charge.

The other thing I've noticed is that the MME takes driving habits into account when calculating range to a far greater extent than my Tesla. That must be why my MME seems to estimate my real-world range more accurately than the Tesla. Aside from gradual battery degradation, the Tesla's range estimate never seems to change by much no matter how I drive. The MME estimated range seems to be a lot more realistic than the Tesla's range estimate.

 

[RickMachE]

Wasn't there some discussion about regen and the Mach-E at 100% from the woman that heads it up?

 

[Gloff]

That is what my guess are but can't get anyone (officially or unofficially) to confirm it. It ONLY happens when I am at 100%. If I use the brakes manually, it doesn't have to issue so I don't think its the rotor. I am guessing its bad logic (software) when the battery is at 100% and it won't let the Mach-E do the regen so it needs to apply the physical brakes instead. Its just the braking is not smooth.

Interesting. A previous poster suggested that the Regen is cycling, which could be part of it.

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