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In the Fully Charged episode[1] linked in a recent thread here about some guy in Amsterdam making electric cars and boats, the guy mentions that the motors have brushes. I was mildly surprised as I just assumed they'd be brushless DC motors.

Are they just efficient enough that the cost/simplicity outweighs going brusless? Or are there other advantages to using brushed motors for electric vehicles?

[1]: https://www.youtube.com/watch?v=7zz3H0pSQ4Q

⬐ guntars

Perhaps it’s simpler and more efficient speed control circuitry. For a DC motor you just need to step down the DC voltage from the batteries. For a brushless motor you basically need a variable frequency inverter that’s necessarily going to be more complex and possibly less efficient.

⬐ hwillis

Yep, mainly. You still need basically the same circuitry, but 3x simpler- you only need one phase instead of three. However you still need the same PWM-type controller to do it. The single phase can operate at several times lower speed though, which makes the output devices and gate drive much cheaper.

⬐ davidgould

Brushed motors are readily available in the appropriate sizes in small quantities and used. Brushless motors not so much yet. Then you also have to use the OEM inverter which will take some reverse engineering or bring your own inverter. People are doing this with car conversions, but it's early days and anyone can wire up a brushed motor.

For my second link to a Fully Charged episode on YouTube today, they did a story about this company in Europe refitting older vehicles with electric gear

Their big plan is to have local river barge traffic be managed with electric tugs instead of diesel, but they’re having fun as they prove the technology. They have a Jaguar XJS converted to the same system as the tug to help debug it

https://youtu.be/7zz3H0pSQ4Q

⬐ rasz

That nasty CRT whine (15KHz) made me instantly guess Siemens old timely brushed system :( You have to be really old to not go insane from hearing it.