EV Brake bed in procedure
Discussion
So looking at the manual for the 5N, there doesn't seem to be a recommended bed in process for the brakes, and with me being relatively ignorant on how it may differ from EV's, I was hoping for some advice. Had a search on the forum, but it didn't seem to pick anything up (maybe I missed it?).
Is it as simple as the usual 'drive normally, no harsh braking' etc just with ensuring that any regen braking is turned off to start with? I've seen quite a few videos where the 5N has been ragged about a bit, and presumably thanks to the monster regen braking, the discs are barely at any real temperature, so again assuming the friction brakes are barely being used.
My main concern is just in case of any need for a sudden stop in the first few hundred miles, and the brakes not biting quite as strongly as expected. Coupled with a heavy vehicle, I'm wondering if it would affect braking distance enough to be a concern - potentially a needless worry, but just something that's popped into my head!
Is it as simple as the usual 'drive normally, no harsh braking' etc just with ensuring that any regen braking is turned off to start with? I've seen quite a few videos where the 5N has been ragged about a bit, and presumably thanks to the monster regen braking, the discs are barely at any real temperature, so again assuming the friction brakes are barely being used.
My main concern is just in case of any need for a sudden stop in the first few hundred miles, and the brakes not biting quite as strongly as expected. Coupled with a heavy vehicle, I'm wondering if it would affect braking distance enough to be a concern - potentially a needless worry, but just something that's popped into my head!
I'd expect there to be a time initially where they're not working very well, but as you say Regen will assist greatly, unless you're coming up on the 1st corner of a race track.
I'd do the tried and tested, turn off regen, accelerate to 60, and slam the anchors on. Repeat around 10 times.
I don't have a 5N but my car has a "brake burnishing mode" hidden away, which basically assists you to do the above (disables regen which you can't normall do and beeps when you're going fast enough etc).
I'd do the tried and tested, turn off regen, accelerate to 60, and slam the anchors on. Repeat around 10 times.
I don't have a 5N but my car has a "brake burnishing mode" hidden away, which basically assists you to do the above (disables regen which you can't normall do and beeps when you're going fast enough etc).
Paul Drawmer said:
Just get in and drive it.
If it gives you peace of mind, do a series of 60-0 stops, but it's really not necessary.
I really wouldn’t do 60-0. If it gives you peace of mind, do a series of 60-0 stops, but it's really not necessary.
Do 60-5 ish, but don’t stop. Just let the car keep rolling, then accelerate again. By the fifth stop your brakes will be so hot that you’ll run the risk of transferring pad material to the disc in just that one area under the pads, thus causing what some think is warped discs but is just the pads going over the very small increase in disc thickness.
And I doubt you’d need to do the 60-5mph more than five or six times to achieve any sort of bedding in.
Edited by Tony1963 on Thursday 7th November 06:54
Tony1963 said:
I really wouldn’t do 60-0.
Do 60-5 ish, but don’t stop. Just let the car keep rolling, then accelerate again. By the fifth stop your brakes will be so hot that you’ll run the risk of transferring pad material to the disc in just that one area under the pads, thus causing what some think is warped discs but is just the pads going over the very small increase in disc thickness.
And I doubt you’d need to do the 60-5mph more than five or six times to achieve any sort of bedding in.
What Tony said. Absolutely avoid clamping pads onto a static hot disc.Do 60-5 ish, but don’t stop. Just let the car keep rolling, then accelerate again. By the fifth stop your brakes will be so hot that you’ll run the risk of transferring pad material to the disc in just that one area under the pads, thus causing what some think is warped discs but is just the pads going over the very small increase in disc thickness.
And I doubt you’d need to do the 60-5mph more than five or six times to achieve any sort of bedding in.
Edited by Tony1963 on Thursday 7th November 06:54
Rough101 said:
Tony1963 said:
I really wouldn’t do 60-0.
Do 60-5 ish, but don’t stop. Just let the car keep rolling, then accelerate again. By the fifth stop your brakes will be so hot that you’ll run the risk of transferring pad material to the disc in just that one area under the pads, thus causing what some think is warped discs but is just the pads going over the very small increase in disc thickness.
And I doubt you’d need to do the 60-5mph more than five or six times to achieve any sort of bedding in.
What Tony said. Absolutely avoid clamping pads onto a static hot disc.Do 60-5 ish, but don’t stop. Just let the car keep rolling, then accelerate again. By the fifth stop your brakes will be so hot that you’ll run the risk of transferring pad material to the disc in just that one area under the pads, thus causing what some think is warped discs but is just the pads going over the very small increase in disc thickness.
And I doubt you’d need to do the 60-5mph more than five or six times to achieve any sort of bedding in.
Edited by Tony1963 on Thursday 7th November 06:54
phil4 said:
I'd expect there to be a time initially where they're not working very well, but as you say Regen will assist greatly, unless you're coming up on the 1st corner of a race track.
I'd do the tried and tested, turn off regen, accelerate to 60, and slam the anchors on. Repeat around 10 times.
I don't have a 5N but my car has a "brake burnishing mode" hidden away, which basically assists you to do the above (disables regen which you can't normall do and beeps when you're going fast enough etc).
Turning off regen just turns off automatic, off accelerator regen. The second you touch the brakes the car still applies regen to the highest level it possibly can.I'd do the tried and tested, turn off regen, accelerate to 60, and slam the anchors on. Repeat around 10 times.
I don't have a 5N but my car has a "brake burnishing mode" hidden away, which basically assists you to do the above (disables regen which you can't normall do and beeps when you're going fast enough etc).
Also the traditional 60-almost stop, rinse and repeat procedure will still use mostly regen to retard the car, if you try it a few times and then tap the brake disc it will probably barely be warm. If you were to brake hard enough to exceed the regen rate of retardation, then the physical brakes would do enough to become hot, but you'd likely be at the point of ABS kicking in.
Overall, I wouldn't worry about it - no need to bed the brakes in and it's going to be very difficult to do so in a controlled and predictable manner in any case.
Also to add, I do have my own little gripe with 'performance brakes' on EV's, because they actually tend to offer less actual braking performance in real world driving conditions due to not actually getting hot enough to work at their best.
My current M50 has huge brakes, exactly the same as the current M3. On my past fast BMW's I have had a mix of the M-spec brakes and the standard brakes, the difference is that whilst the bigger M brakes bite harder for longer, they only actually bite harder once they're up to temperature - before then, the standard brakes actually offer more initial bite. That's not a problem in an ICE car, a spirited drive down a twisty b-road and they're heated up and work brilliantly. But in the EV, because so much of the braking force is via regen, it's actually very difficult to get such big brakes into their performance window. for real world driving, more 'bite' would likely be achieved with smaller, standard brakes. It's still not a problem as the regen is so powerful that the overall braking ability is more than enough for public roads - it just makes the huge brakes seem like a bit of a waste.
The M50, like the N5 are designed to be capable at very high speeds or on a track, where the age old 'make the brakes match the power' philosophy makes sense. But on the public road, it probably makes no sense at all. Albeit the huge brakes look the part
My current M50 has huge brakes, exactly the same as the current M3. On my past fast BMW's I have had a mix of the M-spec brakes and the standard brakes, the difference is that whilst the bigger M brakes bite harder for longer, they only actually bite harder once they're up to temperature - before then, the standard brakes actually offer more initial bite. That's not a problem in an ICE car, a spirited drive down a twisty b-road and they're heated up and work brilliantly. But in the EV, because so much of the braking force is via regen, it's actually very difficult to get such big brakes into their performance window. for real world driving, more 'bite' would likely be achieved with smaller, standard brakes. It's still not a problem as the regen is so powerful that the overall braking ability is more than enough for public roads - it just makes the huge brakes seem like a bit of a waste.
The M50, like the N5 are designed to be capable at very high speeds or on a track, where the age old 'make the brakes match the power' philosophy makes sense. But on the public road, it probably makes no sense at all. Albeit the huge brakes look the part
TheDeuce said:
Turning off regen just turns off automatic, off accelerator regen. The second you touch the brakes the car still applies regen to the highest level it possibly can.
I am not sure this is true. On my IONIQ 5, putting the regen to zero turns it off. There is a dash display of the level of current flowing back into the battery, and in this mode none does under braking. Plus the pedal feels different when using the calipers.I sometimes do this for the last few stops before I park up, especially if it’s wet, to heat up the discs and dry them.
FarmyardPants said:
I am not sure this is true. On my IONIQ 5, putting the regen to zero turns it off. There is a dash display of the level of current flowing back into the battery, and in this mode none does under braking. Plus the pedal feels different when using the calipers.
I sometimes do this for the last few stops before I park up, especially if it’s wet, to heat up the discs and dry them.
Every EV I have driven has blended brakes above 5mph or so, and blend regen braking with friction when you use the brake pedal even if regen is turned off (which typically just enables coasting off throttle). BUT I have never driven an Ioniq 5 so it may be the odd man out...I sometimes do this for the last few stops before I park up, especially if it’s wet, to heat up the discs and dry them.
TheDeuce said:
Turning off regen just turns off automatic, off accelerator regen. The second you touch the brakes the car still applies regen to the highest level it possibly can.
I get your point but I'm talking about a specific process in a specific service mode of the car, where it literally walks the techs through doing this, so fully expect it can and does change the regen.phil4 said:
TheDeuce said:
Turning off regen just turns off automatic, off accelerator regen. The second you touch the brakes the car still applies regen to the highest level it possibly can.
I get your point but I'm talking about a specific process in a specific service mode of the car, where it literally walks the techs through doing this, so fully expect it can and does change the regen.But I don't actually think that will technically 'turn off' regen though. It will stop the car presenting a high enough electrical load to the motor to regenerate as it would in normal modes when you lift off the throttle, but the motor is permanently connected to the axles and if you spin any motor, in generates current that has to go somewhere - or at least it does if damaging levels of EMF are to be avoided.
This is where Tesla's are slightly different from most EV's, in that Tesla's apply noticeable regen load to the motor whatever normal mode you're in, whereas most EV's with regen = off will coast, just like the Tesla in it's brake burnishing mode, the motor still spins and generates some current, but the full load of the battery isn't imposed on it so the resultant regen and retardation is very low.
The other thing the Tesla burnishing mode does, in fact the main thing, is to allow full use of the friction brakes in all circumstances - which is indeed pretty useful if you feel the need to burnish your brakes - as I used to frequently with my old BMW's M brakes, as it was the only way to stop the squealing... But I have never needed to do that in the EV's since. I would if the EV needed new pads in order to bed them in, but most seem to only need that at around 100k+ as they use their brakes so little, and hardly ever aggressively.
That does beg the question of whether I should be burnishing the brakes on my EV's when I first take delivery of them... And I never have, with no detrimental effects that I have noticed. It's possible braking performance could be improved if I had I suppose, but the pad wear is even and there's no grooves forming on the discs, nothing to suggest the pad isn't well mated to the disc. Perhaps many manufacturers run a bedding in procedure during the final stages of production - it would make sense as EV's (Tesla aside) do make bedding in more awkward than traditional cars. I'm willing to bet that the vast majority of first time owners wouldn't do it yet there aren't endless stories of brake issues resulting.
I’m on 95k miles on my Polestar 2 in 3.5 years. Driven like I stole it from the off. Still on original pads and discs. 15% worn on the last service 3 months ago. One pedal driving, regen on the highest setting (which is ‘standard’) It might get a brake fluid change at the next service.
grumpy_dave said:
I’m on 95k miles on my Polestar 2 in 3.5 years. Driven like I stole it from the off. Still on original pads and discs. 15% worn on the last service 3 months ago. One pedal driving, regen on the highest setting (which is ‘standard’) It might get a brake fluid change at the next service.
Exactly. I've had loads of powerful ICE cars, and big power required big brakes that were well used, so I'm used to keeping an eye on the wear and how they're seated.In big power EV's... There's nothing to see! They are barely used. The thing is, the bigger the motors you put on an EV, the more retardation via regen those motors are capable of - if you have 300kw power you have near to 300kw stopping power, ahead of needing the friction brakes.
All very interesting but for me personally, the main benefit is we can now have very fast cars without putting up with wheels constantly coated in brake dust
Edited by TheDeuce on Friday 8th November 21:23
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