Scooter hub motor - How hard can I push it?

[wiredsim]

I recently acquired a scooter with a hub motor and I opened it up for the first time and took some pictures. It looks like the controller has given up the ghost so I'm looking for a good brushed controller as a replacement. The big question is how much power this can handle reasonably. The original thread with pictures is here: http://www.endless-sphere.com/forums/viewtopic.php?f=12&t=20252. The existing controller was 36 volts so 48 volts seems to be safe. Would it be better to try and get a controller that can handle higher amps at 48 volts or go to 60 volts? Are the scooter controllers, like the ones from tncscooters worth anything?

Here are the pictures of the dissection, I only removed the one side, as after prying at the other side it started to seem like I was going to break something, so I held off for now. The black line in the first photo represents about 6 inches.

 

[amberwolf]

With brushed motors, the higher you push the volts and amps from what they were, the hotter the brushes run and the quicker they wear. So while the motor may well work on higher power, it will get hotter and probably need to be ventilated to be run at those higher power levels constantly, though it can probably be pushed for short bursts at much higher levels than it started out at, if you don't mind the extra brush wear.

How high is too high? Depends; I've used 24V powerchair motors at 48V ok, at a constant 8-10A with 15-30A bursts, but they are run thru a shiftable chain drive rather than direct drive in my application (when they had been direct drive originally), helping them get to their more efficient speeds quicker.

You might have to just test it and see. I'd recommend adding an internal thermometer, if for no other reason than that if you get the magnets too hot, they will weaken and the motor won't work as well. HOw hot that has to be for that I don't know, but probably not as hot for the older type in these brushed motors as for the neodymium ones common in brushless motors. The other reason for the thermometer is to monitor winding temperature. If they get too hot they insulation will char, and then you can get arcing between coils, and that will fry the motor (and possibly the controller).

 

[wiredsim]

Thanks for the info, its kind of what I suspected that I will just have to try and see what kind of load it can handle at a given power level without getting too hot. Any recommendations on a controller? I was looking at e-crazyman's ebay items and I didn't see any brushed controllers, brushless is all the rage these days.

Thanks!

 

[wiredsim]

Actually I guess I just need to know if the Yi-Yun controllers are considered a Xie-Chang style or of comparable quality. I'm trying to decide if I should go with eCrazyman's 48V 500W controller from eBay, which says max 28amps, (a bit higher then 500w) or one of the higher rated Yi-Yun's from TNC scooter, like the Model LB37 which they say has a max current of 50amps, the YK42-4 is supposedly 40-100amps. It would only be $15 more for the LB37. Am I missing a better option?

 

[John in CR]

Just make sure you get a brushed motor controller, not a brushless. I think you really need to see what your starting point is in terms of max current with the stock controller. Those through axle motor wires aren't going to support 100A, so get that idea out of your head. In terms of voltage 48V is probably fine, but at 60V you're probably getting into risky territory, though if your terrain is flat so you don't draw high current for long periods, it may be okay.

 

[dogman dan]

Brushes will wear and armatures pit pretty fast above 48v, but I wouldn't hesitate to go 48v 40 amps.

The real issue though will be the overall heating of the hub. Increase wattage much, and you will have to proportionally shorten your ride. I was able to toast some brushed hubs quite quickly when I started out with that stuff. You might really want to consider leaving it stock, like 36v 20 amps or so, unless you are planning on really short trips. Those brushed hubs really heat up fast compared to brushless.

 

[slowlane]

Leave it stock for problem free use...unless limits is the interest .

TNC Scooters has $20.00 controllers for 36V , get 500W . Spend $60.00 for 36V 800W if you want , may go faster...may not , depends on how many watts the motor can use .

If you did not see this scoot running , them buy a matching throttle too , don't use the old one . Get test method from TNC , see if old is good for a spare (test before you have a problem ) .

There are many other vendors , I know TNC does ya quick...especially considering international customs red flagging vendors .

 

[wiredsim]

Thanks everyone for the info. I didn't realize you could pushed Brushless hubs more then Brushed, but I supposed that makes sense that it is more limited by the amount of power the Brushes can handle. I did run it myself a few times with SLA's and the acceleration wasn't what I was hoping for. I know that the older SLA's I used were partially responsible for this however. But I do know the throttle is good.

So my plan then for now is to get a 48 volt controller and run 12S LiPo for batteries. I'll probably pick up the YK40-4 controller from TNC for $32. That is rated at 40 amps, though I'm sure that is somewhat over-rated. I'm betting the higher voltage combined with the lack of sagging from the LiPo will improve acceleration significantly.

Thanks!