QS268 Hub Motor Shuts Off When Accelerating

[tedo]

QS268 20kw
ND961800
Amorge 96v 64AH BMS 400A/640PA

When max line amps are reached do these electric things just limit power, or do they completely shut off?

The motor shuts off intermittent when getting on it. It seems to get worse as battery capacity goes lower. This brand new everthing. First few rides so it may be just getting worse, but it did not happen on first ride.

When it turns off all lights, display and power remain on. Throttle and graph page still work.

I have the controller's max Amps set to 470/1500 and then using gear 1 which is 75% so 352A/1125PA mathematically. I think I am hitting the 352 Line Amps in gear 1.

Here are 4 screenshot. One is right before shutoff and next is after shutoff showing throttle still works but nothing happens. After the bike sits for a bit it will go again.

I have screenshots of all my parameters also if that would help. Please help. I love my new bike and want to ride it.

 

[amberwolf]

If the system doesn't actually power off, then the battery BMS isn't shutting off the output. But you could stil have a battery issue where it can't sustain the current demanded from it, and voltage drops so far that the controller itself ceases operating the motor to protect the battery.


You can check your LVC settings in the controller to see if the voltage you see it drop to during the event is at or below that LVC point. If it is, then that's why it's happening. If the controller LVC is at the correct point for the battery you have, then leave it there. If it's too high, it's cutting off early, so although you have a battery problem of too much voltage sag, you can reduce the issue by lowering the LVC to an appropriate point, which is usually 3.0 to 3.2v per series cell (however many S it is).





Normally when any max amps is reached in a controller (hits the current limit), it rolls back output to the motor to lower the current until it drops below the limit, and doesnt' stop operating the motor...unless the load on the motor is so high that it exceeds the limit.

 

[bananu7]

Yeah, I don't know much about the Fardriver app, but it doesn't seem like that's the case. The only thing different between the screenshots is the throttle value, yet it doesn't show any throttle errors either. Maybe it detects an intermittent throttle fault, which clears itself but the controller requires a restart anyway?

 

[dominik h]

When max line amps are reached do these electric things just limit power, or do they completely shut off?

The motor shuts off intermittent when getting on it. It seems to get worse as battery capacity goes lower. This brand new everthing. First few rides so it may be just getting worse, but it did not happen on first ride.

When it turns off all lights, display and power remain on. Throttle and graph page still work.

The controller limits it´s current draw to the set limit.
The BMS turns the battery off if you go over a limit.

Your throttle voltage is going the wrong way, with 0,78V you have highest power and with 3,8V you have no power.
Or there is a time lag between shown power and throttle, but I have never recognized that myself.
How can you make screentshots with 30kW power or are you running on a dyno?

Are you shure you have the DC/DC converter behind the BMS?
If so, and your Fardriver is still powered and you should get an error message in the Fardriver app, which is only reseted when the motor is standing still. I have seen a lot error messages during my tests (Undervoltage, Throttle error, Phase over current, phase short circuit, lower mosfet, upper mosfet...

When you turn on your controller , it does a log file of the first 50 seconds. You can see it under "curve". This could give us a hint what might be wrong.

 

[tedo]

Thanks.

If the system doesn't actually power off, then the battery BMS isn't shutting off the output. But you could stil have a battery issue where it can't sustain the current demanded from it, and voltage drops so far that the controller itself ceases operating the motor to protect the battery.


You can check your LVC settings in the controller to see if the voltage you see it drop to during the event is at or below that LVC point. If it is, then that's why it's happening. If the controller LVC is at the correct point for the battery you have, then leave it there. If it's too high, it's cutting off early, so although you have a battery problem of too much voltage sag, you can reduce the issue by lowering the LVC to an appropriate point, which is usually 3.0 to 3.2v per series cell (however many S it is).





Normally when any max amps is reached in a controller (hits the current limit), it rolls back output to the motor to lower the current until it drops below the limit, and doesnt' stop operating the motor...unless the load on the motor is so high that it exceeds the li

If the system doesn't actually power off, then the battery BMS isn't shutting off the output. But you could stil have a battery issue where it can't sustain the current demanded from it, and voltage drops so far that the controller itself ceases operating the motor to protect the battery.


You can check your LVC settings in the controller to see if the voltage you see it drop to during the event is at or below that LVC point. If it is, then that's why it's happening. If the controller LVC is at the correct point for the battery you have, then leave it there. If it's too high, it's cutting off early, so although you have a battery problem of too much voltage sag, you can reduce the issue by lowering the LVC to an appropriate point, which is usually 3.0 to 3.2v per series cell (however many S it is).





Normally when any max amps is reached in a controller (hits the current limit), it rolls back output to the motor to lower the current until it drops below the limit, and doesnt' stop operating the motor...unless the load on the motor is so high that it exceeds the limit.

Thanks. Not sure what LVC settings are. Is it something I adjust in parameters? Here is a screen shot of my battery

 

[tedo]

Yeah, I don't know much about the Fardriver app, but it doesn't seem like that's the case. The only thing different between the screenshots is the throttle value, yet it doesn't show any throttle errors either. Maybe it detects an intermittent throttle fault, which clears itself but the controller requires a restart anyway?

Do you think it would be worth it to just get a new throttle? I did the self learn 3 times and on one of the times I did get a throttle error. I am using a very cheap ass aliexpress throttle. I am not sure what a "good" throttle is.

 

[bananu7]

Do you think it would be worth it to just get a new throttle? I did the self learn 3 times and on one of the times I did get a throttle error. I am using a very cheap ass aliexpress throttle. I am not sure what a "good" throttle is.

Throttles are cheap, so trying out something else that might be more reliable could be worthwhile. Make sure your throttle limits are set up properly for the throttle you are using as well.

 

[tedo]

Throttles are cheap, so trying out something else that might be more reliable could be worthwhile. Make sure your throttle limits are set up properly for the throttle you are using as well.

Ok thanks. And maybe it didn't do when the battery was full since the line amps would be lower as the volts were higher.

 

[dominik h]

I'm not shure that your throttle is the problem. The fardrive cuts the motor and shows throttle error until the motor is standing still.
You should have seen the error.
There also exists an error log, where you can see which errors have been recognized.

 

[tedo]

I'm not shure that your throttle is the problem. The fardrive cuts the motor and shows throttle error until the motor is standing still.
You should have seen the error.
There also exists an error log, where you can see which errors have been recognized

Oh I didn't know that with my awesome Chinese instructions. LOL. Where is the error log?

 

[dominik h]

Sorry, no real log only an error counter.
Curve > count



And this is a Screenshot from the data logging

 

[tedo]

I have numbers in mine, but no clue what they mean. (Attached)

I think I have some weird setting wrong. Reviewing my videos in slow mo, it shuts down exactly at line amps I set as the limit in "ratios in gears". (Attached). 470 x 75% = 352 Amps.

 

[dominik h]

The errors I had :
MOE was set durig driving without issues but with absolute maximum current settings in the controller , with 10% less everything worked without issues
Over was set when I had the phase wires shorted (over current)
VOL was set after an undervoltage event (BMS cut out)

Your ratios in gears do not shut the controller down.

Post screenshots of all your Fardiver settings.
Normaly the controller is set to reduce power when the battery gets near the low voltage cut off.

 

[tedo]

The errors I had :
MOE was set durig driving without issues but with absolute maximum current settings in the controller , with 10% less everything worked without issues
Over was set when I had the phase wires shorted (over current)
VOL was set after an undervoltage event (BMS cut out)

Your ratios in gears do not shut the controller down.

Post screenshots of all your Fardiver settings.
Normaly the controller is set to reduce power when the battery gets near the low voltage cut off.

Here you go

 

[dominik h]

Your low voltage value is to low

For a 26S battery set
Low vol 81V
Low vol restore 83V

Sorry thought first you have a 28S battery therefore 86 and 88V would be ok.

I would also change

PC13 to Normal response, otherwhise the controller always activates regen when you close the throttle.

For further testing i would also reduce battery current to
Max line current to 400A
Max boost current to 400A

If everything is then ok start raising currents in steps back to 470A.
It's always better to start with a little lower values and then step up when everything is ok.

 

[bananu7]

Your low voltage value is to low
Low vol 86V
Low vol restore 88V

Wouldn't values that are too low never cause the undervolt to activate?

 

[dominik h]

Yes, but the bms will shut off and no one knows how the controller reacts when you cut the battery at full load.
I changed my post above to the values needed for a 26S battery.

My 721800 lowers the current when to voltages drops to low and so the bms will never cut off during driving.

 

[tedo]

Your throttle voltage is going the wrong way, with 0,78V you have highest power and with 3,8V you have no power.

I will review this as I have a video of it happening. I am doing a screen recorder with the app up while I drive.

Are you shure you have the DC/DC converter behind the BMS?

I have a + and - wire going from the controller to the + and - on the converter. They are stacked on top of the wires coming in from the battery to the controller. On the throttle side I am sharing the 12v ground since I figured out the converter has 2 ground wires but they have continuity so assuming the 96v and 12v ground are the same in respect to the converter.

 

[tedo]

Your low voltage value is to low

For a 26S battery set
Low vol 81V
Low vol restore 83V

Sorry thought first you have a 28S battery therefore 86 and 88V would be ok.

I would also change

PC13 to Normal response, otherwhise the controller always activates regen when you close the throttle.

For further testing i would also reduce battery current to
Max line current to 400A
Max boost current to 400A

If everything is then ok start raising currents in steps back to 470A.
It's always better to start with a little lower values and then step up when everything is ok.

So do the 86v and 88v change? It is a 26S battery. And I will make that PC13 change.

With the amp suggestion are saying to raise the ams or lower them? I have it set to max 470 now. I am just limiting it to 352 with the 3 speed switch. I can go to button 2 which is 85% or 400 amps.

I tested it today on button 2 and 3. Both had same failures. I have not reviewed the videos yet but I suspect the motor will die at 400 and 470 amps respectively.

The motor resets bit MUST come to a full stop before it will work again. This must be a clue. It is a few seconds to reset only after coming to a full stop.

 

[tedo]

When you turn on your controller , it does a log file of the first 50 seconds. You can see it under "curve". This could give us a hint what might be wrong.

 

[dominik h]

81 and 83V
And just to be shure everything is ok, lower line and boost current settings to 400A to try.

My ND72680 was set to start from a standstill with boost settings and change to max line current settings after 10 seconds.

 

[tedo]

No idea. Here is a screen shot. May not even be the right page.

I made the Low vol change to 86 and 88? And the 400a max on both line and boost.

It worked perfect in gear 1 as I would never hit 350 Amps. So figured I would try gear 3 and same thing. Shuts down. Except this time everything went to hell. I could not go 10 feet without it shutting off at any power setting. Went back to gear one and no better. The throttle was intermittent and either no go or did burnout like an on off switch and would just shut down in another few feet. Oh and it knew I was in busy traffic. If you are trying to pull out in traffic it WILL shut down. If you are in a quiet neighborhood it does a lot better.

Anyone want to buy some parts? I'm going back to burning gas and nitrous.

 

[dominik h]

The Screenshot from the "curve" is not very useful, as there is throttle and battery voltage and battery current missing.
The gathered values from "curve" get lost after the controller has been shut down and restarted.

Try to make a Video from the app with the meters displayed while bad things are happening, or even better, a split screen video with the bms app opened also.

 

[dominik h]

It took me three weeks to get the ND721800 running.
The ND72680 I had installed before in the same scooter, was running from the first minute on, and I only had a few issues while trying to max put the phase current.
With 10% lower than maximum it was running perfect.

My biggest problem with the ND721800 was software and the second was the BMS I had changed at the same time.

When you have still set boost phase current to 1800A, then reduce it to 1500A and try again.

 

[dominik h]

Set low vol to 81V and low vol restore to 83V for your 26S battery.

Your battery will drop from 101V to maybe 86V at 450A.
I think you want to much from your battery at the moment.

At 10C battery temp I have 11V of sag at 400A and the controller is able to reduce current to every value it needs to not let the battery go under the set low vol value.
At 20C battery temperature it is only 7V of sag.
What is your battery temperature.