HammaMan
Well-known member
Sodium just isn't panning out like LFP is. Modern LFP is now able to achieve 200Wh/kg while retaining absolutely insane lifetimes. Nothing is coming close to just how long they last and that's a variable that can't be ignored.
As for hub motors, we're still not yet seeing the longevity needed from them due to their locations. I haven't seen anything in regards to trying to 'inboard' them a bit like within the A arm 'box' while only requiring a single CV style joint. Each additional motor requires a separate inverter to drive it which increases costs significantly combined with an additional motor. It's at least an additional $2k or so per motor at the manufacturer level. This is why the most common trend is 1 motor per axle. I don't foresee a future where the costs and complexities of hub motors washes their efficiency gain vs the current approach.
Then there's the whole direct wheel drive not really being a realistic approach as the motor's diameter would need to be large, or increased complexity w/ planetaries required. So far the best 'efficiency' has been found to be with motors than can spin up to 30k RPM and geared down to drive the wheels. In traction limited scenarios the larger single motor can still push all of its power to the 'gripping' wheel. In offroad scenarios this has been found to be superior vs hub motors where tractive effort is limited by the output of individual motors. Weak motors have been showing some chinese EVs having trouble off road particularly going up hill where a wheel can lose traction.
LFP's lifespan is yielding vehicles that will go 20+ years needing nothing but gear oil, coolant, and tires when appropriate. Removing the ICE and Trans, combined with regen braking and super long battery life is a whole new paradigm I don't think most people fully understand yet. A nearly maintenance free drivetrain. Given the easy life of the coolant and gearbox oil, I wouldn't be surprised to hear of people never changing them and the vehicle not much caring.
As for hub motors, we're still not yet seeing the longevity needed from them due to their locations. I haven't seen anything in regards to trying to 'inboard' them a bit like within the A arm 'box' while only requiring a single CV style joint. Each additional motor requires a separate inverter to drive it which increases costs significantly combined with an additional motor. It's at least an additional $2k or so per motor at the manufacturer level. This is why the most common trend is 1 motor per axle. I don't foresee a future where the costs and complexities of hub motors washes their efficiency gain vs the current approach.
Then there's the whole direct wheel drive not really being a realistic approach as the motor's diameter would need to be large, or increased complexity w/ planetaries required. So far the best 'efficiency' has been found to be with motors than can spin up to 30k RPM and geared down to drive the wheels. In traction limited scenarios the larger single motor can still push all of its power to the 'gripping' wheel. In offroad scenarios this has been found to be superior vs hub motors where tractive effort is limited by the output of individual motors. Weak motors have been showing some chinese EVs having trouble off road particularly going up hill where a wheel can lose traction.
LFP's lifespan is yielding vehicles that will go 20+ years needing nothing but gear oil, coolant, and tires when appropriate. Removing the ICE and Trans, combined with regen braking and super long battery life is a whole new paradigm I don't think most people fully understand yet. A nearly maintenance free drivetrain. Given the easy life of the coolant and gearbox oil, I wouldn't be surprised to hear of people never changing them and the vehicle not much caring.
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