Motor Cuts Out Randomly

Tyro65

100 mW
Joined
Aug 3, 2008
Messages
36
Location
Sault Ste. Marie, ON
Is it the Cycle Analyst or the controller? I can't figure it out. I know that it is not low voltage because it cuts off even at low speeds when the CA is displaying high voltage.
 
Hi Tyro,
People who might be able to help you will need a lot more information than you have given.. Is it a factory e-bike or aftermarket kit, motor type, does it cut out while using throttle or while pedaling (or both), does the system use torque sensing or cadence sensing for the pedal assist, what type of controller etc etc.
The information you have given probably eliminates battery or battery connector problems, but there are so many other possibilities that extra information is needed before anyone can make suggestions..
 
Something like that could be a bad connection pretty easily. The connection will carry a load to a certain point, then cut out completely. I would look over every connection from the battery itself (internal to the case) to the controller.
 
Thanks for the quick reply. Here's some more information:

Model:
BM1418ZXFDC BrushlessBYW750V48S428G=YCRCTKBC
Motor Model:
BM1418ZXF
Type:
DC Brushless
Bottom Base:
Y
MPN:
BM1418ZXFDC BrushlessBYW750V48S428G=YCRCTKBC
Sprocket type:
428
Brand:
Unite
Wattage:
750
Voltage:
48


It’s an aftermarket kit, 750W geared motor, non-hub. I have it rigged up to drive a sprocket I installed on the left side crank.
It cuts out while using throttle, but the throttle is not the problem. I installed a new one.
It does not have PAS or torque sensor or cadence sensor.

This is the same as my controller:
http://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=163249909563&category=11332&pm=1&ds=0&t=1559890102000&ver=0
 
Tyro65 said:
Is it the Cycle Analyst or the controller?
Two ways to eliminate the CA:

Set the CA throttle input mode to Bypass, this sends the exact same throttle signal out that it gets in, no modification, no limiting, etc.

Or

Disconnect the throttle from the CA, and disconnect the controller from the CA, and connect the throttle directly to the controller.


If the problems still happen, it's not the CA.
 
I gotta disagree with your first procedure, Amber.

If you are going to test a component which may, or may not, be functioning correctly, you must not use a method which depends for its accuracy on the component, which is in question, actually functioning correctly.

You disconnect it from the system and test in a way where the functionality, or lack thereof, of the component in question is not part of the equation.
 
aCeMadMod, the pack I usually use does not have a bms, but I have a pack that does, which I can try. Maybe it's time to manually balance the cells in that pack.
 
Here's the deal with testers - they are great for a problem that happens all the time, or just happens to occur when the tester is connected. However, for random problems, not so much.

You need long-term testing.

Describe your EXACT procedure to restore functionality after the cut-out. Voltage readings?
 
AngryBob said:
I gotta disagree with your first procedure, Amber.

If you are going to test a component which may, or may not, be functioning correctly, you must not use a method which depends for its accuracy on the component, which is in question, actually functioning correctly.

You disconnect it from the system and test in a way where the functionality, or lack thereof, of the component in question is not part of the equation.
In this case, the first procedure given is a few seconds and doesnt' require risk of damaging wires when disconnecting or reconnecting, or miswiring things when reconnecting, etc., which are possibilities.

This is the exact same procedure I just used successfully, a few days ago, to verify that the CA (a setting in it) was causing the cutouts in my own system on the SB Cruiser trike.

When Bypass mode doesn't change it, then some other thing can be causing it.

It might be a connection anywhere in the system (throttle, battery to controller, controller to motor, etc).

It might be a defective controller or motor or throttle.

It might be an ebrake (or ebrake wire) that is triggering power cutoff at the controller (if the ebrake is wired to controller rather than CA).

Etc.

But if Bypass mode *does* stop the cutouts, it means something in the CA settings is limiting the system in a way that causes cutouts under specific conditions. While that might take a bit of settings examination to find out what specifically it is, at least the test to find that out is really quick and easy. ;)
 
But - IF the CA is defective, then IF using bypass mode does NOT stop the cutouts, you have not proven anything because the cause of the defect has not been isolated. The defective component is still in the loop.

The same defect causing the cutout may cause bypass mode to fail to engage.

If you can totally remove a component which might be the source of the problem and still have enough functionality to test, DO IT. A software instruction to go around that component is absolutely not sufficient. The component is still active and electrically connected.

I submit the time used and risk entailed in going thru the menus and changing settings is roughly equivalent to disconnecting and re-arranging a few cables. One procedure gives a definitive answer, the other does not.

Following a process of elimination requires certainty of elimination.
 
"Describe your EXACT procedure to restore functionality after the cut-out. Voltage readings?"

Actually, I have not had a chance to try some of the suggestions. Hopefully, depending on the weather, I'll have a report tomorrow -- and maybe a solution.

Sometimes it runs for several minutes, sometimes it cuts out and then runs again in 10 or 15 seconds even when I still have the throttle cranked. The voltage of the 48V pack is often over 50 when it cuts out.
 
I have the CA set to ramp up gently. It's the reason I bought the CA. The motor was starting up with such ferocity that it was wrecking freewheels. If I set it to bypass mode will it also bypass ramping?

As amberwolf said, "this sends the exact same throttle signal out that it gets in, no modification, no limiting, etc."
 
Tyro65 said:
I have the CA set to ramp up gently. It's the reason I bought the CA. The motor was starting up with such ferocity that it was wrecking freewheels. If I set it to bypass mode will it also bypass ramping?
Yes, but so will every other method of testing that doesnt' use the CA.

The ramping is also something you can do yourself, by very very very slowly increasing throttle input, at least for these tests. That's all the CA is doing, it's jsut doing it electrically direclty rather than mechanically (with your hand) that then changes the electrical signal.

It's your call which thing to do to test stuff.

But if you do want to try bypass mode first, you simply:
-- hold the left button of the CA for a few seconds, till the Setup menu comes up and let go
-- press teh rigth button twice to get to the Throttle IN menu,
-- hold the left button until it goes into that menu, let go
-- hold the left button till it is in set mode for the throttle in type
-- press the right button repeatedly until it shows Bypass
-- hold the right button to accept the change
-- press the rigth button repeatedly until it exits the setup menu and reboots

Now it's in Bypass mode. If the problem persists, it isn't a CA setting causing the problem.

It doesn't eliminate a hardware problem, like a bad connection, of course, but it does eliminate the settings, and it can be put back the way it was with the same steps as above, except that you choose your previous throttle mode rather than Bypass.
 
aCeMadMod,

You asked me if I had BMS.

I was using a non-bms pack on the motor (the one that cuts out) which powers my drive train. I switched that pack with a bms pack, the one that drives my front hub motor. I went for a short run this morning and the motor did not cut out. I will test some more tomorrow, but it looks like you likely identified the problem.

Does the CA detect that cells are unbalanced? I'm curious about how that works.

Thanks.
 
So, you are saying that you are riding along, lose power, then, with no change on the throttle, you do absolutely nothing, and then power comes back on?

And, this happens with a pack with no BMS, while a pack WITH a BMS worked? Was this done only once, and have you carefully checked all wiring connections involved with the battery change, has it happened again, after original battery replaced, and roughly how often does this problem occur? Once a week, every 5 minutes, somewhere in between?

Having a BMS makes such a problem more likely, rather than less.

Does display, if any, go dark? Does your controller have an on switch, or does it come on when supplied with power, with no user intervention required?

This problem may not be load related, but many similar ones are, and testing with the wheel in the air is indeed handy but it removes the load, and that factor alone may prevent the problem from occuring and prevent effective diagnostics.

Follow the power, if display goes dark, then at or previous to controller. If controller requires user intervention to turn on, then after controller. If there are no other indications of loss of power other than no motor, then we are looking at a really simple, but inexpensively made, throttle or wiring, or that complex box with lots of electronics that is inserted between throttle and controller.
The one where you can move a couple cables and completely remove it from the list of possible causes.
 
AngryBob,

See my responses between your lines.

AngryBob said:
So, you are saying that you are riding along, lose power, then, with no change on the throttle, you do absolutely nothing, and then power comes back on?
----Yes

And, this happens with a pack with no BMS, while a pack WITH a BMS worked?
----Yes.

Was this done only once,
----I've switched battery packs only once and that was this morning, but I need to give it a more thorough test.

and have you carefully checked all wiring connections involved with the battery change, has it happened again, after original battery replaced,
----No, but it should be tested on a much longer ride.

and roughly how often does this problem occur? Once a week, every 5 minutes, somewhere in between?
----With the non-bms pack, mostly every few minutes, but it has lasted for more than 5 minutes.

Having a BMS makes such a problem more likely, rather than less.
----Interesting. That makes me think that I have missed a weak connection.

Does display, if any, go dark?
----The Cycle Analyst stays on.

Does your controller have an on switch, or does it come on when supplied with power, with no user intervention required?
----No switch, except one that I have installed in a power cable.

This problem may not be load related, but many similar ones are, and testing with the wheel in the air is indeed handy but it removes the load, and that factor alone may prevent the problem from occuring and prevent effective diagnostics.
----I'll do a more thorough test on the road.

Follow the power, if display goes dark, then at or previous to controller. If controller requires user intervention to turn on, then after controller. If there are no other indications of loss of power other than no motor, then we are looking at a really simple, but inexpensively made, throttle or wiring, or that complex box with lots of electronics that is inserted between throttle and controller.
The one where you can move a couple cables and completely remove it from the list of possible causes.

Thank. You. I'll have a more complete report tomorrow.
 
Tyro65 said:
I was using a non-bms pack on the motor (the one that cuts out) which powers my drive train. I switched that pack with a bms pack, the one that drives my front hub motor. I went for a short run this morning and the motor did not cut out. I will test some more tomorrow, but it looks like you likely identified the problem.
He was asking if you had a BMS, becuse if you *did* have a BMS, then the BMS can shutdown for various reasons, which will cause a motor cutout.

But without a BMS on a pack, then the battery cant' cutout like that, so can't directly cause the motor cutouts. (other things can be wrong, however, that could).

So since the battery that was on there when cutouts happened did NOT have a BMS, then that isn't the cause of the cutouts.

But since a different battery appears to eliminate cutouts, then there are a number ofthings that could cause the cutouts, including settings in the CA (whcih the Bypass test would quickly confirm or eliminate).

This is why I recommended doing this test. But you must do this test and then ride normally, because a no-load test won't reveal a problem, most likely.

Does the CA detect that cells are unbalanced? I'm curious about how that works.
It is not connected to your cells, so there is no way for it to do that.
 
There are a number of reasons it might have a problem with one vs the ohter, but the most likely is:

The second one might have less voltage sag than the first, and the CA's LVC might be set too high, so it cuts out until the voltage stops sagging below that point. The bypass test would eliminate or verify this. If it keeps cutting out it isn't the CA's settings causing a cutout in response to anything.


The first might have more sag because:
--the first has less capacity than teh second
--the first is older than the second
--the first is made of less capable cells than the second
--the first has unbalanced cells, so some of them run out before others and voltage sags dramatically
--the first has connection problmes either within the pack or it's wiring or connectors

etc.

(these are all just reasons sag happens, and I have no way of knowing which, if any, are true of your packs)
 
Fascinating. You may need to go through the 20-page manual for the CA to determine how to change this setting.

However, this does bring us back to your post #1, wherein you state it was cutting out even when the CA was displaying "high voltage". This is where numbers become important. What voltage, exactly, was being displayed? Compare this to voltage readings on the working battery, particularly the lowest reading shown while functionality was maintained.

It may still be a simple random fault. Amperage available may also be involved. I have not read the entire 20-page manual for the CA. I would have expected some sort of error message to be shown, on what is essentially a sophisticated display unit, for these cutouts.

Also, the configuration of each battery now becomes of some importance, and neither the series count, parallel count, cell type, nor the chemistry of either battery has been explained.

Hopefully you have by now a reasonable approximation of how much info was lacking in your very first post.
 
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