I need a solid 24v 500w brushed speed controller

[Adamsmashem]

I have a razor E300 with a 500w motor, and a 20ah 24v lifepo4 battery. (My 500w motor) I had a variable speed controller I got for ~ $50, but after loading it quite a bit, it lost almost all its power. Im looking for a reliable 500w brushed speed controller, for ~ $20 - $60. It does not need to be variable speed. I just need something that can handle a decent beating, and still run fine.

Id appreciate some recommendations!

 

[amberwolf]

It's not very likely the speed controller would cause power loss in this situation (brushed controllers almost always fail stuck on (shorted FETs) or blown completely to not operate the motor at all, but overheated magnets in a motor or cooked commutator/brushes in the motor could, and so could a damaged battery with a cell or cells that can no longer supply the necessary current, or a connector or fuseholder between battery and controller or motor that has overheated and now has high resistance between contact surfaces. Sometimes an unrelated problem like the throttle or throttle wiring can cause the problem.

If you've already eliminated all those are are certain it is the controller, then:

A non variable speed controller isn't a controller, it's just a switch or a relay/contactor. It would need to handle the full current (potentially more than 50A at stall since it won't have any current limiting) at the full voltage (probalby 28-30v full charge), so it will be fairly large and likely of similar cost to an average controller.

I don't know enough about low-cost brushed controllers to say for sure which might take a beating in that price range, but if you don't mind used, you can probably find golf-cart brushed controllers (like Curtis or 4QD) that are good, and being designed for higher currents than you need would not have trouble with your relatively small load. But these will likely be much larger physically than the one you have now.

 

[Adamsmashem]

A non variable speed controller isn't a controller, it's just a switch or a relay/contactor. It would need to handle the full current (potentially more than 50A at stall since it won't have any current limiting) at the full voltage (probalby 28-30v full charge), so it will be fairly large and likely of similar cost to an average controller.

These razors come stock with an on/off controller, basically just a relay and a current limiter. Also wouldnt using a golf cart controller give too much current to the motor, and possibly overheat it? Or can I modify it so it gives the proper power for a 500w motor?

 

[amberwolf]

These razors come stock with an on/off controller, basically just a relay and a current limiter.

To have a current limiter, they must have a "real" controller (that does PWM, etc), which would be able to be variable (that's how the current limiting works, too), so there would be no reason to not have it be variable by throttle.

Unless it just turns off whenever current is above it's limit, which isn't useful because it would shutdown on just about any startup from a stop, etc. which is a primary place for the limiting to be required.

If it's just relays, it can't do limiting unless it also has some electronics to turn the relays off whenever the current is exceeded, but as noted that will happen on startups, etc., and make it a bit pointless to use.

Also wouldnt using a golf cart controller give too much current to the motor, and possibly overheat it? Or can I modify it so it gives the proper power for a 500w motor?

Depends on the controller, and your load and usage / conditions.

The motor will only use as much power as the conditions and load demand. If you are putting enough load on the motor that it could use much more power than it is designed for, for long enough to be a problem, you probably need a bigger motor (and battery) anyway.

You can experiment with various calculators and simulators such as the ebikes.ca motor and trip simulator, etc., to see about how much power it should take for your riding conditions and load (it doesn't really matter what system you setup in the simulator, the approximate power requirements are about the same.


The gearing of the motor to the wheel vs the speed you want to use it at also makes a difference. If it's geared too low it won't reach the speed you want without increasing the system voltage proportionally, and if it's geared too high it will waste more power and heat up more when used at lower speeds at high loads.

 

[Chalo]

Im looking for a reliable 500w brushed speed controller, for ~ $20 - $60. It does not need to be variable speed. I just need something that can handle a decent beating, and still run fine.

Brushed motor controllers in that power range are only slightly more expensive than dirt (regardless what the seller is asking) and should be regarded as consumable, even if sometimes they endure heroically.

500W 24V Brush Motor Speed Controller for Electric Scooter E-BIKE ATV Quad Moped | eBay

This item Suitable for electric bike & scooter. Speed Regulator 1-4 V(Throttle ). Red, Black & Blue: Speed Regulator 1-4 V(Throttle ). Red & Blue : Key Switch(power lock). Usable Motor: 24V500 Watts. Yellow & Blue : Motor connections.

www.ebay.com

Mostly you'll want to select one based on what stuff you have to plug into it.