HS3540 stutters at high power or heavy load (solved!)

[electr0n]

I've had this stuttering problem with my HS3540 since I've had it. I was running 66.6v 40 amps and the stuttering usually happens at high speed into a head wind or if I'm pulling a heavy load like a trailer when I'm accelerating mid range. It's like a rapid stuttering sensation as if the motor is misfiring. It only happens some of the time when I'm accelerating hard in the mid range towards the top speed. I've been ignoring it and just learned to work the throttle in a way that pretty much minimizes it, but tonight I got my new batteries wired up and threw 88.8v 40 amps into it (26" wheel) and now it's stuttering much more noticeably particularly above 50 to 60kph. I can go full throttle somewhere around 50 to 60 and instead of going much faster I just get some rapid stuttering almost like a buzzer effect. This stuttering effect totally ruins the ride for me. I'm not sure what's going on that's causing it.

Does this sound like one of my hall sensors are bad, or maybe a controller issue?

Wheel spins smooth and fast with no load. It also runs fine 85 to 90% of the time except under certain conditions as mentioned above which triggers that stuttering effect. I don't notice any stuttering when accelerating from stop till about 40kph. Then hitting the throttle from 40kph to 60kph + is when it happens.

[snowboarder1493]

I'm a noob so this is going to be a noobish answer, but I had this same problem with Crystalyte x5304 motor. The problem were the wires from the controller. Maybe try running the bike at no load and moving around wires to see if you get any stutters?

[d8veh]

I had it on one of my bikes - stuttering going up hills. It started to get worse with cut-outs so I had to investigate. The cause was a slightly loose phase wire connection.

[electr0n]

I'm going to have to play around I guess. Could be halls, controller or wiring I suppose. Will stick to 66.6v for time being. Will have to pick up some spare hall sensors and wiring. Not looking forward to struggling to get the other side cover off!

[dogman]

Loose or perhaps just undersize phase wire is the likely cause, though it could be controller or halls related.

I had a wire that intermittently rubbed on the tire only when the forks were compressed. It rubbed through one phase wire, cutting all but one strand on the green wire. Ran great at low speed, or no load. Take it out and put a load on it, and stutters. It was hard to spot, not looking like it rubbed when I was not on the bike, bouncing the shocks.

So look hard at all wiring, plugs, contacts that may be backed out, etc as the step one of any troubleshoot.

[electr0n]

I was out for a ride yesterday and my motor started stuttering hard at low speed so I shutdown and pedalled home.

Wiggling the wires around caused the motor to intermittently work normally and go back to stuttering. So I checked the connections between the motor and controller. I found some dirt on one of the phase wires inside the anderson connector. All my halls are soldered together and appeared to be intact. After removing the dirt and taping up my hall connections the motor is running ok at no load. Haven't gone for a ride yet to see if that was the cause of the stutter at higher speed and power. Got my fingers crossed.

[dnmun]

don't open the motor until you have checked the halls first. sounds like bad connection or current limiting. do you use a cycle analyst?

[electr0n]

Yes I do use a cycle analyst but this problem was present before I had one so it's definitely not due to current limiting from the cycle analyst. I just took my bike out for another ride after I cleaned the andersons out which connect the controller to motor, same problem. Motor runs fine at lower power and speeds. At 66.6v and 40 amps 26" wheel into a headwind I can feel some misfiring at times but it's not too bad. When I use 88.8v 40 amps the misfiring becomes much more pronounced, specially when trying to accelerate past 60kph. I can power through it and hold the throttle and still go up to 70kph but the stuttering is really bothersome and can't be good.

It doesn't grind hard with a nasty sound like when a hall wire is cut. It's a more rapid stutter and if I back off the throttle and kind of let the motor get up to speed and apply the throttle more gradually as I approach my top speed it helps. This problem primarily happens when there is a lot of wind resistance and particularly at higher speeds.

I'm going to be trying another controller in the next couple days and that will at least tell me if my controller is causing this issue. If the same thing happens it's gotta be either the hall sensors or the phase or hall wires coming off the motor. I'd really prefer not to have to pull the stator out for fear of damaging it.

One last thing I'll add is that I don't notice any problem when the motor is unloaded even at 88.8v full throttle.

[dnmun]

if the hall sensors were bad it would have the miss at all speeds. you can only check the hall sensors while the motor is still intact. if you open it then you cannot check the operation of the hall sensors.

[electr0n]

Yeah that's what I was thinking. Since this is happening on high power under load maybe one of the phase wires is not getting enough power? Is there a way to test the halls with an led light or something. I don't have a tester.

[dnmun]

.

[electr0n]

OK thanks for that. What kind of voltage range should I expect? Is this basically just to tell if all hall sensors are firing or would an abnormal voltage indicate a problem?

I'm running an HS3540, an ebikes.ca 40 amp controller and an old crystalyte thumb throttle with an led indicator. My hall wires are soldered together no connectors. Phase wires are using anderson connectors. Also have a cycle analyst, that's it. No other accessories. Running lipo at 66.6v 8 amp hours and sometimes 88.8v 10 amp hours. No limiting enabled in the cycle analyst.

[dnmun]

.

[electr0n]

Yes. That is really helpful to know. Thanks again. I will post back after trying the new controller. Would love to get this solved.

[electr0n]

I finally got rid of that annoying stuttering problem. I switched my 12 fet controller to a lyen 18 fet and in the process I noticed one of the phase wires was a little blackish and the anderson connector on that phase was partially melted and probably making poor contact. I had this issue even when all the anderson connectors were in good shape though so it could be something with the controller as well. I'll know more when I get that 12 fet hooked up to my older crystalyte. Anyhow I'm a happy camper. I can now speed in peace

[General Lee]

I had a similar problem. When i run my system under high torque or full load it started to loose power or shutter. I stopped smelled melting plastic and smoke came from the motor cable. The serial motor connector was melted also. The bike still worked a few days till i ripped of the cable from the axle. I found out that they use a 2,5 square/mm for each phase and a 16A connector. This is very poor for a 40A System!
I searched an found a cable with 3,2 square/mm that can take up to 260° C heat. It fits through the axle easily. I replaced the connector with a 40A connector from Harting.
Result: Before the "running" the motor stayed relative cool and the cable got hot. After the changes the motor got warm and the cable stayed cool. Till now the motor doesn´t shutter anymore at high power. And before V-Max was 72 km/h now 75 km/h so more power is now reaching the motor