Can climbing a steep slope blow out the controller?

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davcr
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Can climbing a steep slope blow out the controller?

Hi all,

I just bought a brand new electric scooter and wanted to test how steep a slope it could climb. It seems the scooter didn't like the idea and after 200 m the throttle stopped working. I thought that perhaps it was some sort of current cut off protection mechanism to avoid overheating, but in fact it never worked again. Since the battery seems ok (the lights work, the battery level reads fine) I guess it must be either the motor or the controller what has stopped working. The motor was actually hot after the failed attempt to reach the top of the slope. May the heat have melted the Hall effect sensors inside the motor or something like that? Or is it more likely that it is the controller what has failed? I'd like to know what your guess is or if there is a way to find out, so that I decide whether to buy a new controller to try and replace the old one or not.

The scooter is a Huasha 50QT-17 with a 1500W motor and some JH-A48150-T3 controller. I have been unable to find the manufacturer website (JH from China?). I bought the scooter from an online dealer, and my guess is that it will be hard to get any information from him. The scooter has a brushless DC motor (Huari Group).

Thank you!

sixpax2k9
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Re: Can climbing a steep slope blow out the controller?

Well if that scooter is anything like my xb-600, its possible that it only blew a fuse. It probably has 2 fuses like most do. One for the electrical system of lights etc. (a 10A bus fuse on mine), and one for the controller and motor (a 30A blade fuse on mine). Its possible only the fuse for the power supply to the controller blew out, and since the ignition and dc lighting system is on a different fuse it is still working.

To test the motor, you can use a multimeter to see if there is any voltage on the phase wires when you manually spin the rear wheel. I am assuming that it is a hub motor.

If you made NO modifications to the scooter and it died just climbing a hill why would the warranty not cover it???

Dave ; Tennessee
XB-600.

davcr
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Re: Can climbing a steep slope blow out the controller?

Uh... no warranty. The deal was: bargain price + no warranty. I just wanted the thing to play with it and learn a little, so I was just fine with having no warranty. It only seems that I started playing too harsh.... :-/ But it's ok. I'll learn more this way :-)

It seems this thing does not have fuses (at least that I can find). What it has is a single differential switch that controls the whole supply of current from the battery - it is connected in series between the battery and the controller. The switch did not turn off when the throttle stopped working. The fuses you are talking about are *inside* the controller or somewhere in the outside wiring?

Yes, the motor is a hub motor. I'll check the voltages in the motor leads with a tester while I spin it.

Thank you for your reply!

David.

davcr
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Re: Can climbing a steep slope blow out the controller?

Oh, I found this:

http://endless-sphere.com/forums/viewtopic.php?f=16&t=3484

Down in the page is a description of a circuit with LEDs that can check the integrity of the Hall sensors. You just put some current in them and move the wheel and check whether they send a variable signal as the wheel is turning (they are position sensors, so they should).

So I guess I can check the Hall sensors by that method and the windings inside the motor by testing the voltages generated at the phase terminals.

The information in the link above leads me to the following reasoning: if some or all the Hall sensors "melt", so they fail to give the correct information about the wheel position, then the controller may let through the wrong current intensity, so that could be an indirect way to blow out the controller (it could be an analogous situation to that described in the above link when the wiring for the Hall sensors is incorrect and the controller goes crazy and the current ramps up too much). So then if the motor breaks down for excess of heat or current, the controller will break down too? Is that reasoning right?

sixpax2k9
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Re: Can climbing a steep slope blow out the controller?

While it is possible for a bad motor to ruin a controller I doubt it. First thing I would do is to check the motor for the hall sensors and the phase wires. Take it apart if you feel you must and inspect the windings etc. but if it seems to be giving off a pretty contstant voltage when being manually turned, then the windings are prolly ok. If that seems ok I would prolly open up the controller and start visually inspecting the components. Also while you have your meter out. make sure that the controller is getting power. It just seems odd that the rest of the electical system seems to work fine, and that there are NO fuses... that one is puzzling as I would think mostly ALL dc systems would have a fuse to prevent over amping thus frying the controller. Perhaps the fuses ARE on or in the controller, its possible it could have a fuse hard wired onto the control board. I have seen this before, though not on a scooter controller. I work on printers, faxes, other office equipment etc. and I have seen some with no easily replaceable fuses, though I find this to be a VERY bad design.

If it DOES end up being a fried controller or motor, after replacing of fixing what you must, I would install a blade type fuse between the battery pack + and the controller input + that matches or slightly exceeds the maximum Amperage of the controller. Is this a Li-ion battery system? or SLA? If it is Lithium based there could be a problem with the BMS etc.

It just seems odd that a stock scooter would blow up a controller and/or motor that easily.

After RE-reading the post.... your motor is 1500W what is the Voltage of the battery system??
As I have found with the X-treme hub motors they are rated quite a bit higher as the stock 48V system seems to be able to handle 72V with very minor upgrades to the controller.

My overall guess would be a blown Mosfet in the controller if you cant find any blown fuses etc.
Its very possible that the heatsink on it was not seated properly or not enough heat lubricant and under the highest load it overheated and blew. It may be as simple as buying a replacement mosfet or capacitor and soldering it on the controller board.

Dave ; Tennessee
XB-600.

dogman
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Re: Can climbing a steep slope blow out the controller?

Just riding around blows controllers all the time. It may have been helped by stalling it on too steep a hill, but maybe it was about to blow a cap or a fet anyway. Step two would be to look for something toasty inside the controller, after checking for loose connections. If you don't have a voltmeter, get a 10 buck one and look for voltage going into the controller. If none, there's the problem. A connector can look hooked up, but not let current flow.

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Cruisin
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Re: Can climbing a steep slope blow out the controller?

The answer is YES, you can blow the controller on a 1500w motor going up a steep hill if the controller is defective or of low quality. Many rides that have a 1500w motor also have a controller for a 500w motor as its all about money. If you would like to avoid this problem in the future, email me at cruisin [at] live.com

davcr
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Re: Can climbing a steep slope blow out the controller?

Thank you very much for your reply.

The batteries are silicone gel lead, so it can't be the BMS. The voltage of the system is 48V. Why is that important? I'm pretty much a newbie, and I don't understand the comment about the fact that the "stock 48V system" handles 72V with changes to the controller.

I'll check the motor and the sensors in the sequence you tell me, and then open the controller to see if something looks burnt, either a possible fuse or a mosfet or capacitor.

The controller is located below the seat. It seems that in more recent models, the controller is usually located on one side of the motorbike. Perhaps the location under the seat impairs cooling and that helped some component to get burnt?

davcr
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The final answer

Ok, I tested the Hall sensors using the circuit described above, and they are ok. I turned the wheel and it produced current according to the speed, fine. So I checked for loose wires, and there were none. The battery fed the controller correctly, but no current left the controller through the phase wires. I disconnected the controller and opened it: mayhem. One capacitor had exploded, and the inner fluid was sprinkled on the circuit before it. One LED had leapt out of its bearing. Two integrated circuits had its plastic case melted. The most impressive thing was that the solder on the back of the board had melted and you could see several short circuits. A drop of solder had slid along the wall of the case and solidified again at the bottom of it.

I'll ask the guy that sold me the motorcycle for another controller, but, now: is this a common scenario if a controller fails? It looked as if the inner temperature had exceeded the melting point of tin by far, but I'm not sure if the controller failed for that reason or the other way around: that the temperature went crazy *because* the controller failed. What I fear is that, if I just replace the controller by another one of the same type, it will overheat again. But, if I use a different one, I'll have to spend a lot of time figuring out the correct wiring. If this overheating may be a natural consequence of the controller failing, then the scene I have witnessed is not important in itself. But if it is the overheating what has made it fail, then I should bother to move the new controller to one side of the bike or something so that it does not get that hot again.

What do you think?

MeltedSolder.jpg

dogman
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Re: Can climbing a steep slope blow out the controller?

Like I said, sometimes a controller is just ready to blow anyway. But Really steep hills should be avoided if possible since the motor will pull a huge amperage spike trying to climb it. Most decent bikes can climb 5% or so, but a 10% hill is pretty steep.

Be the pack leader.
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36 volt lifepo4 mongoose mtb
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