KS16s 840Wh problem. Board / batteries / cables?

[Pedro Capitão]

Dear EUC friends, can you help to solve this problem with my KS16s 840Wh?

A couple of weeks ago my wheel started with this problem with original firmware 1.08 (from fabric) and the same with 2.01 firmware (upgraded).

Tell me what do you think about it- it is board, batteries or cables problem?

I power the wheel on, it stays ok for more or less 5-10 min. and then start to tilt back cause saying that is no battery - audio and flashing all red lights without do anything. In the video is not exactly the same I related but now I realised that if I touch charge port with the rubber cap on (or off) I could simulate the problem to do the video.

Other aspects to share with you, problem related:

. this problem can happend when riding wheel - agressive tilt back, the wheel does not power off itself but is dangerous too

. is not all times, sometimes does not do that?!?!?

. full battery, 80% or 30% battery - the problem is the same

. charging with Ks 4.4 Amp charger or the KS 2 Amp one remains the same problem

. I think it could not be the batteries cause if the problem starts after power on and if I power off and power on sometimes till it stays ok, after that I can ride it for 50 kms at average velocity of 24 km/h without more problems.

. Already substitute the buttons up cover cause of the cables - stills the same problem

. When I open the wheel to change tire, verify the cables or so I can ride it normally without having this problem for 2 or 3 weeks everiday... although the problems returns after some days.

. I think it could be the board, is my guess, but I don't know.

 

If you can help or share similar problems you had before, I appreciated.

Thank you very much!

[Chriull]

@Pedro Capitão - seems like some serious wiring/connection/mainboard problem.

Needs some detailed examination to find the fault.

Easiest way would be if you have another ks16s to swap motherboards to see if it solves to problem...

[Pedro Capitão]

16 hours ago, Chriull said:

@Pedro Capitão - seems like some serious wiring/connection/mainboard problem.

Needs some detailed examination to find the fault.

Easiest way would be if you have another ks16s to swap motherboards to see if it solves to problem...

@Chriull  I think that too... but wiring and connection, seems everything in place and well connected... mainboard is my guess.

A friend just sell is Ks16s... I think I will buy another board.

Thanks!

[Chriull]

19 minutes ago, Pedro Capitão said:

but wiring and connection, seems everything in place and well connected

Loose contacts are often not to be seen...

17 hours ago, Pedro Capitão said:

if I touch charge port with the rubber cap on (or off) I could simulate the problem to do the video.

Touching something from the outside and get strange results sounds like loose contacts.

Could of course be also the mainboard, if ypur touching the charge port could influence it? But from the little information here and no physical inspection it put it on second place.

But only speculation from far far away.

[Pedro Capitão]

1 hour ago, Chriull said:

Loose contacts are often not to be seen...

Touching something from the outside and get strange results sounds like loose contacts.

Could of course be also the mainboard, if ypur touching the charge port could influence it? But from the little information here and no physical inspection it put it on second place.

But only speculation from far far away.

The touching of the wheel part was done to make the video, cause at that time I could not simulate the problem, I mean, sometimes I power on the wheel and after 5-10 min or so the wheel start saying "Your battery is low, please charge it" from nothing - goes tilt back, flashing red lights and without touching anything the light get green (bat ok) but still in tilt back position til I restarted. I restart one time or 5 times, depends, the lights gets green and I can ride 50 kms or so! Never seen nothing like that... Trying to correct situation, I open the wheel and do a wiring check, close the wheel panels and I can ride 1 or 2 weeks without the problem... after that the problem get back again... I thought something related to wiring buttons from the upper cover, wiring could touch or interfering with something but can not be cause, again, I can ride normally from 1 or 2 week and after that the problem cames again...

[Seba]

Please go for a ride and use CSV logging to get detailed data log. Then send it to me. Personally I suspect control board, but CSV log would be very helpful in determining the problem.

[Pedro Capitão]

2 hours ago, Seba said:

Please go for a ride and use CSV logging to get detailed data log. Then send it to me. Personally I suspect control board, but CSV log would be very helpful in determining the problem.

Ok, Seba, thanks for help in advance probably I could not catch csv log when the problem goes cause is a kind of random... I'll go for a ride and try. For example, yesterday It happend in the morning for 5 min and It was Ok the rest of the day... let me see how it goes.

[esaj]

I doubt it would be the battery packs themselves, the side-leds show that the voltage measured by the mainboard fluctuates a lot when the charge port is touched. I'd put my money on mainboard or something weird going on with contacts. Since it disappears for some time after dismantling the wheel and putting it back together it could be contacts... Or some weird static build-up issue?

As I recall, the charge port in KS16S goes straight to the mainboard, then separate wires go to each battery pack?

[Pedro Capitão]

22 hours ago, Seba said:

Please go for a ride and use CSV logging to get detailed data log. Then send it to me. Personally I suspect control board, but CSV log would be very helpful in determining the problem.

Nice ride, the problem not happened, but I'd like share the CSV log from Euc World

 

2020-05-07 213003.csv

Edited May 8, 2020 by Pedro Capitão
personal info in file removed

[Pedro Capitão]

13 hours ago, esaj said:

I doubt it would be the battery packs themselves, the side-leds show that the voltage measured by the mainboard fluctuates a lot when the charge port is touched. I'd put my money on mainboard or something weird going on with contacts. Since it disappears for some time after dismantling the wheel and putting it back together it could be contacts... Or some weird static build-up issue?

As I recall, the charge port in KS16S goes straight to the mainboard, then separate wires go to each battery pack?

I think that too, mainboard is causing the problem and is very weird. Yes the battery connects to mainboard and there are other wire and connector to charging port. The upper buttons and cover are brandly new. Picture supplied

[Pedro Capitão]

Does anybody knows what is this 2nd battery wire?

[Seba]

8 minutes ago, Pedro Capitão said:

I think that too, mainboard is causing the problem and is very weird. Yes the battery connects to mainboard and there are other wire and connector to charging port. The upper buttons and cover are brandly new. Picture supplied

I see that two green fuses are bent. Examine both fuses and their sockets. Maybe there is some problem, as fuses shouldn't look like that.

Please also examine electrolytic capacitors and their legs. Your problems may be also caused by broken legs of capacitors or failed capacitors.

Edited May 8, 2020 by Seba

[Seba]

2 minutes ago, Pedro Capitão said:

Does anybody knows what is this 2nd battery wire?

It's used to synchronize BMS charging circuitry. Shouldn't cause any problems during a ride, regardless of it's connected or not.

[Chriull]

16 minutes ago, Pedro Capitão said:

I think that too, mainboard is causing the problem and is very weird. Yes the battery connects to mainboard and there are other wire and connector to charging port. The upper buttons and cover are brandly new. Picture supplied

Can you power on the wheel while opened?

Then you could carefully move single wires and look for malfunctions.

If there are bad connections, they are most probably covered under the insulation/heat shrink tubing.

As you say the buttons and cover are brand new - the probs started after you exchanged them?

As @Seba already noted - the fuses are bend. So some "severe" force could have been applied to the board and some components...

Cracks in the tracks of a pcb are hard to find and can cause quite anything (heat dependend loose connections)

Your "pushing/touching" the charge plug is strong enough to produce by the cover some force on the mainboard?

Imho the board operates without the buttons/charge plug connected! One just needs to short for a moment the connector of the power button to start the wheel. So you could test the wheel without the ?newly attached components? - but be carefull and know exactly what to do! Shorting the wrong connector/wires can easily lead to disaster!

Edit:

Ps.:

The button/charge plug part seem to be exactly above the bent fuses? Maybe the new parts are not properly fitted and apply constant force on the mainboard? So slightest touching/vibrations/whatever cause malfunctions?

Edited May 8, 2020 by Chriull

[Chriull]

@Pedro Capitão - if there is really some bad contact caused by the fuses, especially if only caused by one of the fuse the battery packs could (theoretically?) be at different voltages! Once contact is established again this could lead to some disaster, too...

.... so please be very carefull handling this wheel! ....

[Pedro Capitão]

5 hours ago, Seba said:

I see that two green fuses are bent. Examine both fuses and their sockets. Maybe there is some problem, as fuses shouldn't look like that.

Please also examine electrolytic capacitors and their legs. Your problems may be also caused by broken legs of capacitors or failed capacitors.

I notice that before but they always been like this - I brought this wheel from 2nd hand and I ride at least from August 2019 till started the problem, lets say 2000 kms without issues...

Some days ago when I was inspecting wires and capacitors they seem very solid related to solder and capacitors seems in good shape, not in oval shape (don't know how to say this) but the problem seems to occur between a 22º-25º C - after that temperature everything stays alright - it's solder again because raising the temperature to a better level... could be!

I have to inspect the board again... However today it was possible to register the csv log while the problem occurred (touching charging port) for a short period of time but not during the riding. I made a video showing EUCWorld too.

 

2020-05-08 120727.csv

Edited May 8, 2020 by Pedro Capitão
personal info in file removed

[Chriull]

14 minutes ago, Pedro Capitão said:

csv log

Maybe you want to remove "personal" data from the csv like gps coordinates, telephone id, time zone and wheel serial number?

Maybe a nice additional feature to the EUC World website to create "anonymized" csv logs ?in two steps? - first without "private" extra data and a second with also not gps coordinates, @Seba?

[Seba]

Personally I suspect motherboard, specifically circuit that is responsible for voltage measurement. It may be linked with bent fuses and I fully agree witch @Chriull that some mechanical stress that bent fuses would also cause damage to some tracks on PCB. If the problem would be with battery circuit, this would lead to cutting off. This however doesn't happen - wheel is working and keeping you stable and only tiltback kicks in as microcontroller managing the wheel is detecting low battery condition.

[Seba]

5 minutes ago, Chriull said:

Maybe a nice additional feature to the EUC World website to create "anonymized" csv logs ?in two steps? - first without "private" extra data and a second with also not gps coordinates, @Seba?

Good idea. I'll add option to export anonymized version.

[Chriull]

5 minutes ago, Seba said:

If the problem would be with battery circuit, this would lead to cutting of

Very very theoreticly the capacitors could keep up the voltage supply, if the loose connection from or within the battery is "solid enough" to only cause short interuptions. Or caused by tracks on the pcb cuircit (or whereever else)

Anyhow - if it's just some miniscule simple to fix problem or "the last warning" the wheel gives to you - try to make a systematic and thorough search for the failure. Best with support of a good friend, experienced with electronics.

[Chriull]

Ad hoc, two other ideas regarding the "loosing voltage" for short periods:

Some temporary short curcuit of the motor wires (bad insulation), especially were they enter the axle (but should not have any relation to your touching the charge plug)

Inverter failure (mosfets, control logic) 

Both should be seen in the log by high currents while tjis failure occurs.

Without high currents it should be some supply connection prob?

Btw - if this happens while driving are there any balancing problems?

[Pedro Capitão]

27 minutes ago, Chriull said:

Ad hoc, two other ideas regarding the "loosing voltage" for short periods:

 

Hi, trying to awnser all questions / considerations:

Some temporary short curcuit of the motor wires (bad insulation), especially were they enter the axle (but should not have any relation to your touching the charge plug)

I don't think so motor wires are well protected, in place and should do the proble all time when riding and not sometimes - after the problem I can ride the wheel safelly and fast for 50 km - for many times this ocured

 

Inverter failure (mosfets, control logic) 

Both should be seen in the log by high currents while tjis failure occurs.

Don't know - I believe not - the wheel is 1200w motor / 3000w max I pushed hard yesterday to 26Amps, briefly high hills - It's OK

 

Without high currents it should be some supply connection prob?

No, charge is a 4 Amp - for 840Wh bat is not considered a fast charger - 0,35C, I think! Already charged 2 or 3 times with borrowed 2 Amp charger - does exactly the same.

 

Btw - if this happens while driving are there any balancing problems?

Yes it happens but I cannot show you, I tryed to get a possible log on last rides but usually I don't ride logging the ride, but I must do that from now on.

While riding and the problem starts it does a agressive tilt back caused by the drop in voltage (I think) showing red light and refering 0% bat. In this case I turn off and on the wheel the leds goes green (no matter if the %bat was in 100% or 50% or even 20%) and the problem can occur again 2, 4, 5 times (in 5 ou 10 min. riding) it depends, but after that I can ride without problems for 50 kms.

 

Let me try to sumarize some previous questiions:

 

Can you power on the wheel while opened?

Yes, leaving the board in place cause of the gyro that is keeping wheel leveled and put the up cover to the side, like in photo.

 

Then you could carefully move single wires and look for malfunctions.

If there are bad connections, they are most probably covered under the insulation/heat shrink tubing.

Already did that, but I need to do with eyes wide open - I'm not a specialist in eletronics but I know the basis.

 

As you say the buttons and cover are brand new - the probs started after you exchanged them?

No, the new cover was give to te by a friend to mislead problem

 

As @Seba already noted - the fuses are bend. So some "severe" force could have been applied to the board and some components...

I think that too, but I could not realised if I did something wrong another time before I changed de up cover, when I replaced the tire, for example.

 

Cracks in the tracks of a pcb are hard to find and can cause quite anything (heat dependend loose connections)

Your "pushing/touching" the charge plug is strong enough to produce by the cover some force on the mainboard?

No, the video shows just a slightly touch does that

 

Imho the board operates without the buttons/charge plug connected! One just needs to short for a moment the connector of the power button to start the wheel. So you could test the wheel without the ?newly attached components? - but be carefull and know exactly what to do! Shorting the wrong connector/wires can easily lead to disaster!

I would like not to do that cause I don't know how to short the right wires/connectors. 

 

Edit:

Ps.:

The button/charge plug part seem to be exactly above the bent fuses? Maybe the new parts are not properly fitted and apply constant force on the mainboard? So slightest touching/vibrations/whatever cause malfunctions?

Yes, very true... could be that problem... thera are just one reason to the bent fuses - they are just aligned in the charging port place... 

 

Very usefull you questions and considerations, sorry for my English, I hope you understand all awsers.

I appretiated very much. Thanks!

[Pedro Capitão]

1 hour ago, Seba said:

Personally I suspect motherboard, specifically circuit that is responsible for voltage measurement. It may be linked with bent fuses and I fully agree witch @Chriull that some mechanical stress that bent fuses would also cause damage to some tracks on PCB. If the problem would be with battery circuit, this would lead to cutting off. This however doesn't happen - wheel is working and keeping you stable and only tiltback kicks in as microcontroller managing the wheel is detecting low battery condition.

Yes, I see. Nice consideration... Im refering  that too at @Chriull questions / considerations.

I have 2 speared fuses that I can replace and try to see if pcb nearby lanes are damaged too...

My main question is if the problem was battery related issue - I really like this wheel but I don't want to spend 700€ or so in 840Wh batteries... probably I would prefere by a new wheel as an upgrade, maybe a similar but more confortable, the KS 18L (not XL, cause of the weight).  That's my dilema!

...or to solve the problem buying another ks16s mainboard... I remember that could be also other issues, if you observe the right componentes in mainboard picture they are with a yellow color and seem that they lose the isolation layer and can be causing gyro causing this issue too!

 

Thank you very much, @Seba for your effort

[Pedro Capitão]

3 hours ago, Chriull said:

Maybe you want to remove "personal" data from the csv like gps coordinates, telephone id, time zone and wheel serial number?

 

Ok, Did that! Thanks!

[mrelwood]

Do I see a damaged shielding on one of the battery cables? (Circled in yellow.)

I wonder if the top cover is close enough to the mainboard that if the cables are not placed carefully when putting it back together, the cables will bend the fuses and press on the mainboard. Or maybe even damage the cable shielding and cause a shortcut through the charging connector.