Small backup motor controllers.

Electric Motors and Controllers
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Schlafmutze   10 W

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Small backup motor controllers.

Post by Schlafmutze » Dec 02 2016 11:53am

Hello, figured I'd start a new thread about backup controllers, especially for e-bikes.

Seeing the tendency for certain controllers to fail, wouldn't a small backup controller permanently installed be a good idea?
I looked into running cheap RC ESCs for emergencies, but it seems that they use PWM signals instead of analog for control, possibly making it too much hassle for such a cheapo solution.

How does RC ESCs handle larger high power hub motors, even when cooled down and ran way under spec?


Another option, especially if running higher voltages than ESCs can handle would be something like this.

http://www.ebay.com/itm/36V-48V-60V-72V ... SwcLxYIDZm

http://www.ebay.com/itm/DC-12V-36V-500W ... 2625039866
Anyone have any experience with this?
Sensorless would be a advantage I'd imagine.

(Edit, feel free to move thread to the appropriate sub-board.)

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amberwolf   100 GW

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Re: Small backup motor controllers.

Post by amberwolf » Dec 03 2016 2:36am

I do actually still ahve a Grin Tech 6FET mounted on CrazyBike2 as backup in case of one of the 12FET's failing, but in the ~3-1/2 years it's been on there, I have never had to use it. I'd actually even forgotten it was there, until you posted this. :lol:

But if you use good enough controllers, and don't push their limits, you probably won't have any trouble with them., and never need a backup.

The only thing in them that's likely to fail over time is the capacitors, so you could periodically check those for swelling, leaking, etc., if you like, and replace them if they show any signs of a problem--but this should take years.


If you use cheap controllers, and/or push their limits, then there are higher chances for failure.


I've rarely had a controller failure that wasn't caused by pushing limits in some way--either overcurrent, too close to FET voltage limits, or too hot (causing capacitor failure in that case).



That said, if I had the money to do it, and wasnt' just using spare parts I had laying around (like the 6FET), I would have *identical* spare controller(s) to the main one, so that I could just swap right over to it and have the same operational specs I had with the main one, rather than reduced or questionable performance with a smaller controller that will make the bike behave differently than you're used to.

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