Scooter for oldies, fast battery drain.

[Pippo]

Hallo, everybody. I am new to the forum. Recently, I also just started repairing e-bikes and scooters. I have been repairing various types of electronics and ordinary bicycles for a long time. For the first time, I have encountered such a thing, when the scooter can only cover about half of the intended distance.

Opening the choke, after apprx. 60% of gas, changes the switching of the MOSFET. Video

https://www.facebook.com/video.php?v=753959353138271

Is that correct? I don't know how to explain such a problem in YT and not found answers or video.
The battery is new. Motor 350W from Xiaomi M365. Hall sensors are fine, all 3 phases windings 2.4 Ohm. Throttle fine. The engine consumes 15-40 watts when idling. When starting at full throttle, the initial consumption is around 800 watts.

 

[amberwolf]

Can't access facebook videos. If you post it publicly on Youtube then you can use the MEDIA button when posting to put it into your post directly.

I don't really know which of the several possible questions posed in your thread that you are actually asking, but:

If you aren't getting the same range you used to, it's probably a battery problem, where the cells are imbalanced from some internal cell or interconnect fault.

If your motor is taking more power than it used to, it's usually because of a mechanical problem causing excess friction--that usually causes that part to get excessively warm or even hot (bearings, brakes, tire rubbing on frame, etc).

If your motor is not running like it should because the FETs are not driving the phases correctly, then any of these are possibilities:
Controller:
--one or more FETs has failed
--one or more hall sensor pullups has failed
--controller has forgotten the phase/hall order (or it's been reset or changed)
Motor:
--one or more motor windings has failed (shorted or open)
--one or more phase wires has failed (shorted or open)
--one or more hall sensors has failed (stuck on or stuck off)
--one or more hall wires has failed (shorted or open)
Both:
--water intrusion has corroded something,
--connectors or contacts have failed (usually open or poor contact)


There's other possibilities, depending on exactly what problem / symptoms you have, and what happened to the system or was done to the system before the problem started, assuming that the system worked correclty before, and has stopped working correctly now.

 

[Pippo]

Thanks for response. I will try to post a video to understand the problem.

https://fb.watch/q-NJeTbneD/

When I turn the gas handle, the order in which the phases are connected is A-C, B-A, B-C. After 60% of throttle order is A-A, B-B, C-C. Is that correct?

 

[Pippo]

Can't access facebook videos. If you post it publicly on Youtube then you can use the MEDIA button when posting to put it into your post directly.

I don't really know which of the several possible questions posed in your thread that you are actually asking, but:

If you aren't getting the same range you used to, it's probably a battery problem, where the cells are imbalanced from some internal cell or interconnect fault.

If your motor is taking more power than it used to, it's usually because of a mechanical problem causing excess friction--that usually causes that part to get excessively warm or even hot (bearings, brakes, tire rubbing on frame, etc).

If your motor is not running like it should because the FETs are not driving the phases correctly, then any of these are possibilities:
Controller:
--one or more FETs has failed
--one or more hall sensor pullups has failed
--controller has forgotten the phase/hall order (or it's been reset or changed)
Motor:
--one or more motor windings has failed (shorted or open)
--one or more phase wires has failed (shorted or open)
--one or more hall sensors has failed (stuck on or stuck off)
--one or more hall wires has failed (shorted or open)
Both:
--water intrusion has corroded something,
--connectors or contacts have failed (usually open or poor contact)


There's other possibilities, depending on exactly what problem / symptoms you have, and what happened to the system or was done to the system before the problem started, assuming that the system worked correclty before, and has stopped working correctly now.

1. Battery is new, hold 12Ah from manufacturers 11,6Ah. Old battery shows 8,6 from 10Ah.
2. Opened motor couple of times, there I see some light scratches on rotor, but this is possible from how strongly the magnets pull in the rotor. Changed bearing with slight free side movement to new. No rust, all 3 phases windings shows identical 2.4 Ohm, Hall sensors are fine.
3. Controller:
- FETs fail is possible, but easy test with chainese tester and multimetrer to diode continuity, shows OK
- Hall sensors too tested with dual methods, seems to be OK
- controller problem is possible. No one open and diagnose scooter before me, no access from BT or cable, but maybe something happens with MCU.
I don't know if the problem started suddenly or if it is long-term and started sep-by-step.

 

[amberwolf]

Thanks for response. I will try to post a video to understand the problem.

https://fb.watch/q-NJeTbneD/

When I turn the gas handle, the order in which the phases are connected is A-C, B-A, B-C. After 60% of throttle order is A-A, B-B, C-C. Is that correct?

Can't access facebook videos. If you post it publicly on Youtube then you can use the MEDIA button when posting to put it into your post directly.

Phase order can't change from the throttle amount, unless you have wired up a device with switches, relays, or contactors to do this. Since that would cause the motor to not operate, I can't imagine why you'd do that.

 

[amberwolf]

1. Battery is new, hold 12Ah from manufacturers 11,6Ah. Old battery shows 8,6 from 10Ah.

So you have two different batteries...but I still don't understand what your specific question is.

You already know that the old battery has less capacity than the new one, which will mean less range under the same usage conditions if all the hardware is the same capability between the two, so there's no question to answer there.

If you have a specific question you'd need to state it along with relevant information to it.

I can try to guess what your specific question might be, but there are at least hundreds of possibilities from the given information, and I don't have that much time.

2. Opened motor couple of times, there I see some light scratches on rotor, but this is possible from how strongly the magnets pull in the rotor.

Can't know what the scratches look like without pictures of them, but if they're circumferential vs axial, they're from physical rotor/magnet interaction, or debris inside the motor between those. If it's not debris, it means the rotor is not centered on the stator/axle and so the gap is smaller on one side than the other, so the motor wont' work quite as well as if it were centered--but it should still operate "normally".

If they're axial, they're probably from the motor assembly/disasembly, and that's very common.

Changed bearing with slight free side movement to new.

If the new bearings have lateral movement, you need to replace them with non-defective/damaged ones that don't have that.

If you instead mean that the entire rotor now has lateral movement when it did not before, then either the bearings are not as wide as the old ones and you'd need to add more spacers or replace existing spacers with wider ones to fix this, or the bearings are the same width as before but you haven't put the spacers that came in the motor back in when reassembling.

If you mean something else, you'll need to be specific and detailed.

I don't know if the problem started suddenly or if it is long-term and started sep-by-step.

Without knowing anything about that, or what might have happened to the system before the problem started, it can be harder to figure out the problem.

 

[Pippo]

Maybe YT give me access

First 4 seconds in video throttle opened from 0 to 60%, last 5 sec. to full throttle.

 

[amberwolf]

I see what appears to be the hall sensor? pattern changing, but without knowing what exactly your tester is showing us, how your tester is wired up to the system, how the system itself is wired, how you are performing the test, etc., I don't have any suggestions on either what you are seeing, whether or not it is a problem, or what you can do to change it.

I don't hear a motor running, so I don't know what effect the above has, or what potential problem it might cause, etc.

I still don't know what specific problem you are having, what specific questions you have about it, etc. Until you tell us it's pretty hard to help you.

 

[Pippo]

I know it's hard to understand what I want I was hoping that one of the forum members encountered a similar problem.
New video and sound from motor.

The vibration is mostly from a bad tire, and supported on a soft seat. Made in China throughout

 

[amberwolf]

I know it's hard to understand what I want I was hoping that one of the forum members encountered a similar problem.

Until you tell us what exactly those are, it's going to be difficult for any of us to understand, or to know if they have encountered it.

Perhaps take some time and sit down to figure out what exactly it is that you do want, and exactly what problem you're having.

Then write these down as specifically and clearly, including all of the information about them, so that others will know.

Right now you're asking us to help you but expecting us to have information you have not provided, and that only *you* know.

All the videos in the world will not help if you don't tell us in your post what you want, and what problem you are having that you want us to help with.