Motor drive cuts out

[Gray haired Aussie Bloke]

I have a 36v TDSZ2 running of a 17AH battery on a roadbike . About January I replaced the controller as it had malfunctioned after about 13 mmonths
All was ok until two weeks ago.
I was pushing up a 10% hill when the motor ceased driving and the VLCD 5 display went blank.
I attempted to turn on the display but it wouldn't come on until I turned the battery off an on. On the ten km remaining for the ride this happened twice more.
On the supplier's advice I checked the blue gear and it was undamaged. However when I removed the motor I noticed that I had pinched the red and black torque sensor wires between the motor and the case. It had taken all this time for the pressure to break through the wire insulation.
The power drops out when I apply torque to the pedals.
The higher power setting less torque is needed for the power to drop out
I coated the wires with silicone then reinstalled the motor and controller but the issue was still there.
I then purchased a new controller and installed it then test rode the bike
The new controller didn't fix the issue. Something I noticed is when I reset the system and turned on the display the readings defaulted back to the readings before all this started.
So where do i go from here

 

[offGridDownUnder]

So where do i go from here

You wrote that the new controller did fix the issue. What problem do you want help with?

 

[Gray haired Aussie Bloke]

Wow just look at that. Goes to show that one must proofread the post before pressing the enter button. No the new controller didn't fix the problem hence this request. Thanks very much for bringing that to my attention. other readers are probably asking the same question:-((( Have amended the post

 

[E-HP]

What is your battery charging routine, and how old is it? If the display is going blank and you need to cycle the battery, then you have a battery problem, and the BMS is shutting it down. Could be a weak/low cell group. How often to you fully balance the battery pack?

 

[fechter]

It sounds like a battery problem and the BMS is tripping. If possible, you'd want to try measuring all the cell group voltages in the pack to see if one is low. It may only drop out under load if you have some weak cells. Sometimes the pack gets out of balance and you can manually charge the low group(s) to bring them up, but this would usually indicate some other problem like bad cells or a bad BMS board.

 

[amberwolf]

If the system actually loses power (display turns off) then your battery's BMS is turning off to protect the cells from overdischarge due to the voltage drop under load.

This is usually a problem with one specific cell (group) that's failing, but it can be a general pack problem with aging or damage.

You'll need to first verify that the battery is indeed shutting off it's output when loaded sufficiently, and then before doing anything else, open it up and measure the voltages of the cells (groups). For a 36v battery, that's 10 series Li-Ion cells (or 10 groups). All should be exactly the same voltage. If they are not, write down all of the voltages and post them here, starting at the most negative (closest to battery negative) cell / group. (the lowest voltages are probably the cells/groups causing the problem).

Fixing the pack would require replacing any of the cells that are different from the majority.

Temporarily allowing the pack to be used may be able to be done by just leaving it on the charger for a few hours, days, or weeks (depending on the severity of the problem and the BMS design), to rebalance it, assuming that the BMS is a balancing type (not all are), but this doesn't fix anything, it just makes all the cells the same voltage at full charge; the voltage sag is still the same but may temporarily be scaled such that it doesn't drop below LVC and cause battery shutdown at least when hte pack is full (as it empties over a ride it will revert to the way it was before).

I have a 36v TDSZ2 running of a 17AH battery on a roadbike . About January I replaced the controller as it had malfunctioned after about 13 mmonths
All was ok until two weeks ago.
I was pushing up a 10% hill when the motor ceased driving and the VLCD 5 display went blank.
I attempted to turn on the display but it wouldn't come on until I turned the battery off an on. On the ten km remaining for the ride this happened twice more.
On the supplier's advice I checked the blue gear and it was undamaged. However when I removed the motor I noticed that I had pinched the red and black torque sensor wires between the motor and the case. It had taken all this time for the pressure to break through the wire insulation.
The power drops out when I apply torque to the pedals.
The higher power setting less torque is needed for the power to drop out
I coated the wires with silicone then reinstalled the motor and controller but the issue was still there.
I then purchased a new controller and installed it then test rode the bike
The new controller didn't fix the issue. Something I noticed is when I reset the system and turned on the display the readings defaulted back to the readings before all this started.
So where do i go from here

 

[Gray haired Aussie Bloke]

If the system actually loses power (display turns off) then your battery's BMS is turning off to protect the cells from overdischarge due to the voltage drop under load.

This is usually a problem with one specific cell (group) that's failing, but it can be a general pack problem with aging or damage.

You'll need to first verify that the battery is indeed shutting off it's output when loaded sufficiently, and then before doing anything else, open it up and measure the voltages of the cells (groups). For a 36v battery, that's 10 series Li-Ion cells (or 10 groups). All should be exactly the same voltage. If they are not, write down all of the voltages and post them here, starting at the most negative (closest to battery negative) cell / group. (the lowest voltages are probably the cells/groups causing the problem).

Fixing the pack would require replacing any of the cells that are different from the majority.

Temporarily allowing the pack to be used may be able to be done by just leaving it on the charger for a few hours, days, or weeks (depending on the severity of the problem and the BMS design), to rebalance it, assuming that the BMS is a balancing type (not all are), but this doesn't fix anything, it just makes all the cells the same voltage at full charge; the voltage sag is still the same but may temporarily be scaled such that it doesn't drop below LVC and cause battery shutdown at least when hte pack is full (as it empties over a ride it will revert to the way it was before).

Ok This reply is to all who responded. The system was installed on the bike in January 2021 on average I ride the bike every Monday and Friday for approx 50km a ride. There have been a couple of periods because of medical reason the bike wasn't ridden for 6 weeks or so. According tho the display the total distance ridden is 4291km. Four times I have ran there battery down to one bar on the display. My charging regime , most times, is to put it on charge after every ride but there have been a few times when, as stated above , when one bar was showing on the display. On reading the Wiki I checked the background settings and found that I couldn't consistently get a reading about the torque settings. Of the dozen or so times I went through the sequence it only displayed once or twice and the settings read zeros.
When to motor cut out the bike was VERY hard to pedal.. So I ask the question, could it be the torque sensor not functioning because of the short circuit when the red and black wires short circuited.

 

[fechter]

If the 5v line feeding the torque sensor was shorted, this could take out the display and other functions.

 

[Gray haired Aussie Bloke]

If the system actually loses power (display turns off) then your battery's BMS is turning off to protect the cells from overdischarge due to the voltage drop under load.

This is usually a problem with one specific cell (group) that's failing, but it can be a general pack problem with aging or damage.

You'll need to first verify that the battery is indeed shutting off it's output when loaded sufficiently, and then before doing anything else, open it up and measure the voltages of the cells (groups). For a 36v battery, that's 10 series Li-Ion cells (or 10 groups). All should be exactly the same voltage. If they are not, write down all of the voltages and post them here, starting at the most negative (closest to battery negative) cell / group. (the lowest voltages are probably the cells/groups causing the problem).

Fixing the pack would require replacing any of the cells that are different from the majority.

Temporarily allowing the pack to be used may be able to be done by just leaving it on the charger for a few hours, days, or weeks (depending on the severity of the problem and the BMS design), to rebalance it, assuming that the BMS is a balancing type (not all are), but this doesn't fix anything, it just makes all the cells the same voltage at full charge; the voltage sag is still the same but may temporarily be scaled such that it doesn't drop below LVC and cause battery shutdown at least when hte pack is full (as it empties over a ride it will revert to the way it was before).

I will need guidance to fulfill this request. I have a multimeter so lead on and I will advise of my readings. Photos would be a great help. Thanks.

 

[E-HP]

When to motor cut out the bike was VERY hard to pedal.

Is it hard to pedal if you just shut the system off as well? The battery BMS tripping may not be the problem, but it might be a result. Maybe you have a bearing that's seizing up, or something else mechanical going on, and the BMS is tripping on overcurrent.

 

[Gray haired Aussie Bloke]

Hi there. Attached is photos of battery from each side. The top of the battery is the top of the photo as orientated on the downbar of the bike.
I don't see ten groups of batteries. the way the cells are connected. Please advise where I am to take the voltage readings from. Thanks

 

[offGridDownUnder]

I see 5 groups of 10 cells each showing clearly in the 'Battery two' image - is this what you mean?

 

[Gray haired Aussie Bloke]

I will need guidance to fulfill this request. I have a multimeter so lead on and I will advise of my readings. Photos would be a great help. Thanks.

Ok all, Have checked out the battery voltages this morning. I am pleased to announce that all battery voltages are abopve the 37v range and are within .2v in variation so the battery is in great condition as far as I can tell which is a relief for me. So where do I look now. Thanks all.

 

[AussieRider]

G'day Gray.
Were the voltage readings taken hot off the charger? Bad cell groups often only show up after a bit of a load ie: they drop faster. Run the bike for a bit then check voltages. Feel how warm the motor gets. Check that the hub motor spins freely & that there's no drag from the brakes.
Good luck mate

AussieRider

 

[E-HP]

Ok all, Have checked out the battery voltages this morning. I am pleased to announce that all battery voltages are abopve the 37v range and are within .2v in variation so the battery is in great condition as far as I can tell which is a relief for me. So where do I look now. Thanks all.

Do you mean 0.02V ?

 

[Gray haired Aussie Bloke]

G'day Gray.
Were the voltage readings taken hot off the charger? Bad cell groups often only show up after a bit of a load ie: they drop faster. Run the bike for a bit then check voltages. Feel how warm the motor gets. Check that the hub motor spins freely & that there's no drag from the brakes.
Good luck mate

AussieRider

Thanks for your input. I have a TSDZ2 mid mount motor. No, the battery hasn't been on charger for at least a week probably longer. The motor spins freely and the brakes aren't binding. There appears to be continuity in the torque sensor but it is not showing up in the hidden settings. I have ridden the bike on my trainer but I will say this that there is not the resistance on it as on the road. I cannot replicate the situation on the trainer at all regardless of what i have tried. There is no voltage showing on the red/black wires that come from the controller that connect to the torque sensor.
What other things can I try to rectify thjis situation Thanks

 

[amberwolf]

Ok all, Have checked out the battery voltages this morning. I am pleased to announce that all battery voltages are abopve the 37v range and are within .2v in variation so the battery is in great condition as far as I can tell which is a relief for me. So where do I look now. Thanks all.

0.2v is very very badly imbalanced, so much so that some smarter BMSs will not even let you charge or discharge the pack because this indicates serious cell problems that need to be repaired (usually by replacing the cell groups that are different from the majority).

When you say "all battery votlages are above the 37v range", do you mean each cell is 37v? If so, there is something wrong with your voltmeter causing it to display many times the actual voltage, or it is setup incorrectly for the measurement you are trying to do. If you can show exactly how you used the meter to do your tests, including the settings you used on it, it will help us see if it is correctly setup and connected to the cells to test, and if it isn't then we can suggest changes to help you get correct measurements.

If you mean that the entire pack at it's main positive and negative is above 37v, then that's at best halfway charged for a 36v (10s) Li-Ion pack. What does the entire pack at it's main positive and negative read when you have plugged in the charger until the charger turns itself off (or it's light turns green, etc).

 

[Gray haired Aussie Bloke]

Ok This reply is to all who responded. The system was installed on the bike in January 2021 on average I ride the bike every Monday and Friday for approx 50km a ride. There have been a couple of periods because of medical reason the bike wasn't ridden for 6 weeks or so. According tho the display the total distance ridden is 4291km. Four times I have ran there battery down to one bar on the display. My charging regime , most times, is to put it on charge after every ride but there have been a few times when, as stated above , when one bar was showing on the display. On reading the Wiki I checked the background settings and found that I couldn't consistently get a reading about the torque settings. Of the dozen or so times I went through the sequence it only displayed once or twice and the settings read zeros.
When to motor cut out the bike was VERY hard to pedal.. So I ask the question, could it be the torque sensor not functioning because of the short circuit when the red and black wires short circuited.

0.2v is very very badly imbalanced, so much so that some smarter BMSs will not even let you charge or discharge the pack because this indicates serious cell problems that need to be repaired (usually by replacing the cell groups that are different from the majority).

When you say "all battery votlages are above the 37v range", do you mean each cell is 37v? If so, there is something wrong with your voltmeter causing it to display many times the actual voltage, or it is setup incorrectly for the measurement you are trying to do. If you can show exactly how you used the meter to do your tests, including the settings you used on it, it will help us see if it is correctly setup and connected to the cells to test, and if it isn't then we can suggest changes to help you get correct measurements.

If you mean that the entire pack at it's main positive and negative is above 37v, then that's at best halfway charged for a 36v (10s) Li-Ion pack. What does the entire pack at it's main positive and negative read when you have plugged in the charger until the charger turns itself off (or it's light turns green, etc).

Ummm, I charged the battery overnight and the charger light was green this afternoon at about 2.30pm when I unplugged it. The battery was slightly warm when I took it off charge, Will wait till later this arvo to check it out. Standby for the next chaper as I seek to discover what the challenge is. I'll get back with photos show where I'm taking the readings from and the result. Curiouser and curiouser.

 

[Gray haired Aussie Bloke]

Ummm, I charged the battery overnight and the charger light was green this afternoon at about 2.30pm when I unplugged it. The battery was slightly warm when I took it off charge, Will wait till later this arvo to check it out. Standby for the next chaper as I seek to discover what the challenge is. I'll get back with photos show where I'm taking the readings from and the result. Curiouser and curiouser.

It's now 6pm with the battery now cool. Attached are photos of where I took the readings from last time but as is stated I didn't measure properly. The photos show the same voltage for each bank. There is also a photo of the voltage at the battery connector to the motor.