Xiongda 2 Speed 2 Wheel Drive and my issue

[BARE]

The Xiongda 2-speed intrigued me, having just built a vintage MTB 2 wheel drive conversion and finding the old fire look out ridge top roads were too much slow travel for the average hub motors. But now, having just completed the 2 wheel drive, 2 speed conversion, I find my chariot is out of sorts. Yes I have a 52 volt battery and a 48 volt controller on a 36 volt 300 watt motor. But I have the amps dialed down to 11 and I was just putting around on my first day's test when the bike starts to buck and bite like and old mule. Now, I point out that both KT LCD 4 displays are currently showing the brake symbol accompanied with no thrust. If, occasionally, the symbol is missing then one motor will spin, although weakly, while the other will spin a moment before 'nothing'. I've double checked all connections, and all look perfect. How is it that both motors are interacting while only being connected with the hand brake cutoffs and the HAL 2 speed switch. The controllers are joined with two XT60 connectors mating to one, to the battery. I'm not so electrically minded to dig deep. I imagine Eric Hicks of Luna Cycle knows my woes, but that was a past life time for him, yes?
Any thoughts?

 

[neptronix]

how does it respond with the brake switch and 2 speed switch disconnected?

 

[BARE]

No difference. I'll try placing a jumper in place of the brake switches, but I think it's something else. The battery level symbol on the worse motor display shows no charge, while the battery is 100% and the other display shows that accurately.

 

[neptronix]

Smells like a controller problem but i don't know a lot about KT stuff

 

[BARE]

Yeah, I'm fearing that possibility as well, but I want to believe the quality is better than that, being new and around a while. But...

 

[amberwolf]

AFAIK the KT controllers use N.O. ebrake signals, so offf when unconnected. Jumpering them turns on the ebrake in those cases.

Some 48v controllers have an HVC that will prevent normal controller operation when the battery is above 55ish volts. It may also not show the correct voltage on the battery meter. A 52v battery is full at about 58v. Does it make a difference to rundown the battery to it's average voltage of 52v and retest?

The KT controllers ahve a fair number of settings that affect their operation. There may be settings in the controller that affect it's HVC and/or meter display, and there should be settings regarding some of the motor parameters, speedometer/wheelsize/etc., and current limiting, assist level operation, and other response/behavior settings.


I think you already said "no difference" to this, but just to be sure: What happens without the "HAL 2 speed switch" attache d? (I don't know what it specifcially does to operate the two-speed system, but if it is interferringg with normal operation....)

 

[BARE]

Thank you for all of that.
I will recheck those issues and report back in a few days.

 

[BARE]

My pursuit of the problem had me switching the connections between controllers, displays, motors. I have found that the front motor is the issue. Switching everything else to that motor, including disconnecting the shared brake cutoffs and HAL 2 speed switches, had no effect. The rear motor works fine with all options.
The one point I need to restate is that I purchased two 36 volt motors and matched them to two 48 volt controllers (with 63 volt capacitors) and a 52 volt battery. Xiongda mentioned that I should have 48 volt motors, but I insisted on 36 volt. They did not make any statement of a serious issue, like it could cause me immediate problems such as I'm having, and I seem to remember someone doing as I am doing, on this forum years ago, with no mention of ill effects.
Any ideas?

 

[amberwolf]

Unless the Xiondga has (unlike most hubmotors) electronics in it that run off battery voltage and aren't meant for the 48v, then the main side effect is that the 36v motor will spin proportionally faster at the 48v.

The higher voltage on the same resistance of windings may also make higher currents (and higher power), when under load; depends on the controller and the load.

It might overheat the motor if it can't shed the extra heat generated in the process, especially if the new higher unloaded speed is a lot higher than the fully-loaded speed you run at when at full throttle.

But it wouldn't cause the controller to generate a brake lever icon or error code or word on the display--the only thing that could do that, if the generated data actually means brake lever is engaged, would be the brake signal being read by the controller as being engaged, for whatever reason.

So, best guess is something is wrong with the front motor itself, such that it is interfering with the 5v supply in the controller by having a shorted 5v hall supply wire inside the motor or inside the cable from motor to controller, to any of the other wires (but especially ground or worse one of the phase wires).

 

[BARE]

Based on your detailed analysis, confirming my process of elimination, I disconnected the 9 pin plug from the front motor and saw nothing amiss. I then reattached it and fiddled with the wire as it comes out of the axle, where it makes the 90 degree exit from the cap shield to head up the front fork. Bingo! It is working! So I have a poor connection there or near by. Babying that area does not seem like a confidence builder since I ride alone many miles out in the back country. Do you have an idea to remedy this?

 

[lnanek]

There are YouTube videos where people open up motors and run new cables through the axle. It's pretty involved, though. Many motors even need a gear puller contraption that lets you pry them open by slowly turning a screw to force pushing one side away from the other.

I'd probably cut the cable short right near the bend, strip the wires, and solder replacements on there before I try it. Might fix the break without all the trouble if there's a tiny bit of good wire sticking out there before the break.

 

[BARE]

Well I'm going to run with it for now and see what transpires before pushing my repairing skills. The advantage of redundancy plays a roll in this instance, which is a big reason I chose to run with dual motors in the first place, being a solitary soul in solitude. I plan to report back at some point, since I find so many threads that never give the final outcome..

 

[BARE]

A HUGE REVELATION.
My issues are a result of the sharing of both, the cut off brake switches AND the HAL 2 speed switch to both controllers. I thought nothing of splicing the brakes and 2 speed switch to both controllers, but what a bunch of quirks and dysfunction resulted. Even my thinking the front motor was a problem turned out to be the result of the above. My solution is that I now have the front brake cutting off the front motor and the rear brake cuts off the rear motor. The HAL 2 speed switch is still being shared, but, so far, the one quirk with that is that powering up only one display and controller does not function properly. Turning on both displays and controllers results in a completely normal result. Again I must point out that having two systems in hand made the process of elimination more efficient. It is a frightening sight to see all of the wiring and connections with two controllers. Look at the controller and its wire harness, something like 26 individual wires plugged into matching wired plugs, times two. Crazy! It was daunting, for a rookie, but coming here was a game changer.

 

[glennb]

The issue with dual brake lever switches to dual controllers is solvable if you decide it’s important to have each brake lever able to cut power to both controllers. There’s various means, by way of relays, diodes, reed switches, and likely others.