If one were to replace the TM3 battery after 300K miles, would motor performance essentially be restored to "like new?" AFAIK there isn't anything to wear out beyond the main bearings, which will probably last long enough to render them irrelevant.
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Does electric motor performance degrade?
- Thread starter Dolemite
- Start date
No one should own a car that long. If you are buying a used car you should not expect a new car like performance out of a 300k mile motor.
At 300K miles a M3 would be rattling so much there would be panel chips falling out of your hair when you shower.
They definitely degrade. The question is what does 300k mile degradation look like and how does it compare to ice degradation? I’d be curious to know if 3-400k on an electric motor is similar to say 50-100k on an ice in terms of performance and reliability.
The idea 50-100k degrades adequately sized ICE is delusion.
Sure some of the undersized turbo motors but in general engines today make a lot of power and last a long time. The EV enthusiast idea that ICE are fragile, failure prone and wear out fast is not honest.
As we are seeing with the S and X though the biggest threat to long term Tesla performance is Tesla, but maybe with the shorter warranty on the 3 they won't screw you like they have the older S owners.
Sure some of the undersized turbo motors but in general engines today make a lot of power and last a long time. The EV enthusiast idea that ICE are fragile, failure prone and wear out fast is not honest.
As we are seeing with the S and X though the biggest threat to long term Tesla performance is Tesla, but maybe with the shorter warranty on the 3 they won't screw you like they have the older S owners.
Knightshade
Well-Known Member
High-Mileage Tesla Model S P100D Matches Wits With Almost-New Tesla Model 3 Performance @ Top Speed
Roughly 7% hp loss from new on a P100D at ~100k miles
Course that could be at least a little bit from the batteries age too... and it's on dual induction motors-(and an older one than the 3 uses up front - plus we don't yet know if the perm mag motor on the back of the 3 will age differently.)
Roughly 7% hp loss from new on a P100D at ~100k miles
Course that could be at least a little bit from the batteries age too... and it's on dual induction motors-(and an older one than the 3 uses up front - plus we don't yet know if the perm mag motor on the back of the 3 will age differently.)
The biggest impact, by a wide margin, is the battery aging. The motor does ‘degrade’ to some extent, but it could be effectively considered to be zero until failure, at least in terms of mechanical output vs electrical input. PM motors are at higher risk of power loss, but it’s still basically zero outside of extreme cases or bad design.
However, the battery WILL age, use it or not. And given how Tesla designs the vehicles, this is a big factor. As the battery ages, it will increase its reluctance to output power. The voltage will drop a bit more for the same load, which nets lower power. This also causes higher internal heating than when new. This ‘internal resistance’ rise is why EVs may get slower as they age. Internal resistance is somewhat independent to the capacity loss, so you can’t really check it just by determining the remaining capacity. Heat and time tend to be the major factors. This can be mitigated with chemistry and design, but it’s just one of the factors to take into account with pack design.
To be clear, it’s entirely possible to design an electric vehicle that does not slow down as it ages. However, the way Tesla deigns them, the battery is often run close to the limit, so aging will impact performance. The closer to the limit, the more significant this will be. I suppose we have to wait until newer designs start shipping to see how this trend continues. Although given the historical data, presumably Tesla would just push a better battery harder if given the chance.
However, the battery WILL age, use it or not. And given how Tesla designs the vehicles, this is a big factor. As the battery ages, it will increase its reluctance to output power. The voltage will drop a bit more for the same load, which nets lower power. This also causes higher internal heating than when new. This ‘internal resistance’ rise is why EVs may get slower as they age. Internal resistance is somewhat independent to the capacity loss, so you can’t really check it just by determining the remaining capacity. Heat and time tend to be the major factors. This can be mitigated with chemistry and design, but it’s just one of the factors to take into account with pack design.
To be clear, it’s entirely possible to design an electric vehicle that does not slow down as it ages. However, the way Tesla deigns them, the battery is often run close to the limit, so aging will impact performance. The closer to the limit, the more significant this will be. I suppose we have to wait until newer designs start shipping to see how this trend continues. Although given the historical data, presumably Tesla would just push a better battery harder if given the chance.
Are you willing the ignore the eventual oil, coolant and transmission fluid puddles under the ice? Or the engine dancing in the engine bay on worn out mounts? I'd still bet on the electric motor.
SomeJoe7777
Marginally-Known Member
There is degradation in the electric motors over time, but the key difference between electric motors and internal combustion engines is that the degradation in the electric motor generally does not affect performance.
The insulation/dielectric begins to break down, resulting in a lower threshold for an internal short circuit at high voltages. The bearings wear, slightly increasing friction losses. The permanent magnets may have a tiny amount of magnetism loss, but in the PMSR motor design, this only impacts efficiency, and very little.
The net result is that yes, the motor does degrade, but none of these will measurably affect the peak power output, temperature/cooling, torque, or efficiency. At some point, something will degrade to the point of failure (likely the bearings will be first), requiring a motor replacement, but with many fewer things to go wrong, this extends the overall motor life well past an ICE.
The insulation/dielectric begins to break down, resulting in a lower threshold for an internal short circuit at high voltages. The bearings wear, slightly increasing friction losses. The permanent magnets may have a tiny amount of magnetism loss, but in the PMSR motor design, this only impacts efficiency, and very little.
The net result is that yes, the motor does degrade, but none of these will measurably affect the peak power output, temperature/cooling, torque, or efficiency. At some point, something will degrade to the point of failure (likely the bearings will be first), requiring a motor replacement, but with many fewer things to go wrong, this extends the overall motor life well past an ICE.
XLR82XS
D M C
Where's the million-mile motor tear-down video? Someone did it - Tesla maybe?
XLR82XS
D M C
Say that to the 500-750k club guys that are SAAB and Mercedes owners.
jelloslug
Active Member
Neither of those things would be even noticeable unless the cooling system was damaged and the motor was severely overheated.
I've seen more comments of puddles under Tesla's than I've seen on most ICE Forums.
Hmmm, if my motor mounts ever wear worn out, I just replace them. Problem is, I have not seen a bad motor mount in decades.
But I only ran my ICE cars to about 200K miles.
Tesla's have plenty of bushings to wear out too.
Next you'll be saying EV's don't wear out tires too.
Tesla's are pretty complex, probably have more fluid in them than most ICE cars do.
My concern comes when the motors are used as HV battery heaters. The thing is that the current going to the motor is controlled so, more Id than Iq is supplied and therefore, losses in the motor plates are produced. Ok but this is not free at all and it produces additional wear and tear. So let's see how the motors age, specially those in the cars who have suffered more DC fast charging.
Tesloop Taxi service has multiple cars at this mileage (and beyond) and some with battery replacements, maybe you can hit them up and see what they say?
- Here's how a Tesla Model S holds up after 400,000 miles in 3 years - Electrek
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