Originally Posted by shrowell
Thank you - so I assume that would mean over time the permanent magnets could weaken, whereas the Tesla battery would not. I wonder what the life of our magnets are?
, absent abuse or extreme heat, the magnets used in electric motors retain their power, well, permanently. I don't think this is an issue you need to be concerned about.
"Tesla battery?" I assume you meant the Tesla Motor. Again, the choice between Induction and Permanent magnet motors is driven by a number of factors and they each have their positive and negative points. I don't think magnet longevity really factored into the decision.
Here is an article
that compares the various electric motor designs. It may be bit too detailed for casual interest, but I thought you may find it interesting. Specifically, this quote is very relevant to this thread (Note, the Tesla mentioned in the quote is a unit of measure of magnetic density, not the car):
The magnets in permanent-magnet motors
Rare-earth elements are those 30 metals found in the periodic table’s oft-omitted long center two rows; they’re used in many modern applications. Magnets made of rare-earth metals are particularly powerful alloys with crystalline structures that have high magnetic anistropy — which means that they readily align in one direction, and resist it in others.
Discovered in the 1940s and identified in 1966, rare-earth magnets are one-third to two times more powerful than traditional ferrite magnets — generating fields up to 1.4 Teslas in some cases.
Permanent magnets are used in MRI machines, portable electronic devices, hysteresis clutches, accelerometers, and — last but not least —permanent-magnet rotary and linear motors.
Hope this helps.