agniusm
1 MW
What about rulleing out bms? could you connect your batt bypassing bms to the controller?
First ride, almost runs. Please help
- Thread starter chrashing
- Start date
dnmun
1 PW
he can rule out the BMS by measuring the cell voltages. i think he has one cell really low and one really high that cuts off charging. he said his charger is green but we don't know the balancing current. unless he actually did measure the voltage on the battery and it read 60V.
chrashing
100 mW
I think that is a great idea, seems safe enough with a 30amp fuse in the circuit, and I'm guessing a 30 second test would not do any damage to a healthy pack. I'd just need get a good connection to wires directly from the battery.agniusm said:
Here are my battery voltages, with the charger connected and a green light 60V, then a few hours after disconnecting the charger the battery measured 57.5V. Then after sitting a day or two and then connecting to the trike, at the controller input: 54V motor off, 53V wheel turning under no load, and then 50V with a load enough to cause the motor cut off problem. Are these levels a bad indication?dnmun said:
If I should need to measure the cell voltage, is that to measuring each cell of the pack? I think there are like 80, and really don't want open up the duct taped case. Or is this done by measuring the individual signals lines from the battery pack to the BMS?
Finally have a picture of the BMS guts,
chvidgov.bc.ca
10 kW
You can test the cells (or cell groups, not sure which depending on what is inside) by disconnecting the white connector with the white signal lines from the bms, and probing the contacts of each one - first one from neg on battery to first white one, and then in ascending adjacent pairs of contacts up the connector to get the voltages of each group. Voltages are difference in volts between adjacent connector pairs. This BMS is typically found on Headway packs, I've got several of them, and I like them better than the Signalabs. Its also possible to charge a single cell or cell group through the same contacts (the white signal lines) with a single cell charger to manually balance the cells. Fully charged is typically around 3.7 on the BMS as I recall for each group. and they should be "close". This BMS balances well with good heat dissipation
dnmun
1 PW
you can measure the voltages while the sense wires are still plugged into the BMS too. i thought you had 54V off the charge so if you have 57.5 it should be fairly charged up unless that BMs won't balance but i think it will.
but if the bike shuts off again, then check the gate voltage on the mosfets to see if it is the BMS shutting off that causes the bike to die.
that is the usual reason for the short trip and shut off early. knowing if it is balancing the pack is useful because the Vpower packs can have a row shorted too. so measure them to be sure.
but if the bike shuts off again, then check the gate voltage on the mosfets to see if it is the BMS shutting off that causes the bike to die.
that is the usual reason for the short trip and shut off early. knowing if it is balancing the pack is useful because the Vpower packs can have a row shorted too. so measure them to be sure.
DAND214
10 MW
Usually if the BMS trips due to lvc it will not rest without unplug or cycling the key.
So it should not be thg BMS.
But I'm not sure all BMS are that way so as said check cell voltage to make sure you don't have a dud.
Dan
So it should not be thg BMS.
But I'm not sure all BMS are that way so as said check cell voltage to make sure you don't have a dud.
Dan
dogman dan
1 PW
Backing up a bit, It's starting to sound less like a throttle issue. If the throttle works normaly with the wheel off the ground, then it's working.
One possibility is a poor connection at the phase wires plug, but I'd expect some chattering under heavy load if that was the real problem. But look at that big three wire plug to the motor anyway again. It does resemble a false forward motor wires combination, but that would be unlikely that if they mis wired the motor or controller, that it would run at all with wire colors matched.
It's starting to look like some kind of issue with the battery. 50v under load for a freshly charged to 60v battery is not normal. The battery should drop to 54-56v very soon, but then it should not sag 4 v unless loaded very hard. But you'd expect the usual bms shutoff if a cell is not holding a charge, then the power goes off completely, and requires an unplug to reset it.
So it just might be a wonky controller.
One possibility is a poor connection at the phase wires plug, but I'd expect some chattering under heavy load if that was the real problem. But look at that big three wire plug to the motor anyway again. It does resemble a false forward motor wires combination, but that would be unlikely that if they mis wired the motor or controller, that it would run at all with wire colors matched.
It's starting to look like some kind of issue with the battery. 50v under load for a freshly charged to 60v battery is not normal. The battery should drop to 54-56v very soon, but then it should not sag 4 v unless loaded very hard. But you'd expect the usual bms shutoff if a cell is not holding a charge, then the power goes off completely, and requires an unplug to reset it.
So it just might be a wonky controller.
chrashing
100 mW
Conhis has replied, based on the voltage results with the wheel off the ground testing, thinks the main problem is the controller limiting the current. So will be replacing the controller.
Ykick
1 GW
chrashing said:
Probably best to work with them so as to maintain warranty you may be due. Of course, it's gonna take some time if they need to ship a new controller. Knowing what I know now, I would've gone with a Lyen or similar programmable controller domestically available. Too many translation issues and lack of programming support to mix/match Chinese factory controllers, IMO.
Looking back to the "250W limit" connector, have you tried testing with that engaged? That should limit current enough to avoid tripping normal controller overcurrent protection?
This excersize highlights the need for a power meter and appropriate connectors to best troubleshoot these systems. EPBuddy sells a rebranded Turnigy power meter which ships domestically, I'd suggest one of those while you wait for another controller. Or, go pro, grab a CA from eBikes.ca and enjoy the best power meter/management device of it's kind.
chrashing
100 mW
Conhis updated me and is suggesting that the 1000W controller is not compatible with the smaller 350Watt motor. This was suggested on this thread early and I had discounted, thinking it was a efficiently issue. I'll try the 250Watt mode, and have to get another controller.
chrashing
100 mW
Shorting the white wires has the same results, The motor cuts-out with anything but a small acceleration. The shorted white wires did change the amount that I had to turn the throttle to get a reaction, so I know the short was made.
Ordered a smaller, 500w controller from Conhis that will work. They have provided great support.
Ordered a smaller, 500w controller from Conhis that will work. They have provided great support.
chrashing
100 mW
agniusm said:
I just tried this suggestion. Made up a little jumper cable to connect the battery outputs (before the BMS unit) directly to the controller power input before the fuse. Took the precaution of moving the trike out of the garage before plugging in. (So I could kick it into yard if it flamed!)
Initially, it seemed to work better for the first 1-2 seconds, then the same motor cut out effect as before. Rode for about 30 seconds with the motor cutting out. So this test verifies that the BMS is not the issue. That leaves the controller as the problem.
Hope/expect the battery is ok. Measured 53.7V when I was done, put it on the charger, charged for 60 seconds and then stopped charging with 60V measured. Has not gone into that cell charging mode for over an hour now, so it must still be balanced.
dnmun
1 PW
that controller is not causing the bike to run outa juice in no time. do you disconnect the battery from the controller after use? or do you have a switch?
agniusm
1 MW
as said here you should get cell voltage reading on bms for individual cells. from negative go pin 1 and 2, then 2 and 3, 3 and 4 and so on. Note the voltages. Still worth checking out even if you ordered another controller. I dont see why 1kw controller shoudn't work with 350w motor. Where is compatibility issue here?
chrashing
100 mW
I thought the battery voltages were good. I'll have to check those cell voltages sometime. Seems I have nothing better to do for a couple weeks.dnmun said:
I did some searching but didn't find anything confirming a controller/motor size problem. But I know less about motor controllers than I know about BMS and battery packs. I could imagine the large controller possibly expecting a greater inductive reaction than a small motor will provide from it's windings, but I'm making up an explanation fit the problem. Don't know if that is real....agniusm said:
I'm betting the controller is the problem, whether it's bad or just incompatible.
mushymelon
1 kW
.
chrashing
100 mW
chrashing said:
Profiled to the best of my understanding the cell voltages. Still cautious about shorting two probes across the cells, measured relative to Ground then calculated the Cell Voltage. Verified the low V cells and was accurate.
This is after being charged, then left sitting for 5 days.
chrashing
100 mW
I'm not sure how to judge these results, but I'm happy that all are above 3.2V. Think I've read that they should overall be within 0.1V, they are close. At this point, I'm hoping some charging cycles will improve things. The battery has only about about 1 mile of loaded use on it. Don't know, but expect the balancing would improve with a few charging cycles. Also I am not sure the proper stage to measure the Cell voltage. Would it be better to have the battery under load for some time first before checking the cells?
I'm learning, slowly... Now that I know the battery is made up of 80 count 3000ma cells, (count seems excessive). Since I see a lot of threads about checking for bad cells, I expect there is a large reliability impact of having so many cells. And so many individuality cells must add weight/size.
I'm learning, slowly... Now that I know the battery is made up of 80 count 3000ma cells, (count seems excessive). Since I see a lot of threads about checking for bad cells, I expect there is a large reliability impact of having so many cells. And so many individuality cells must add weight/size.
agniusm
1 MW
That cell does look low compared to other ones and they don't look balanced to me. My BMS from cellman balances cells within tenth of a volt.
The voltage does not say about SOC of the cell. It could be that 3.34V cell is not charged and when you engage throttle a bit harder that cell SAG's to the level where the BMS cuts out the power, and when you re-engage it cell is back up gain and things start over. I would try to charge that group if you have means or even better charge each group to the same level and then connect BMS.
Being said all that, i forgot that you have tried running without BMS, so this thinking might be wrong.
The voltage does not say about SOC of the cell. It could be that 3.34V cell is not charged and when you engage throttle a bit harder that cell SAG's to the level where the BMS cuts out the power, and when you re-engage it cell is back up gain and things start over. I would try to charge that group if you have means or even better charge each group to the same level and then connect BMS.
Being said all that, i forgot that you have tried running without BMS, so this thinking might be wrong.
dnmun
1 PW
if you have a 60V charger then the cells should charge up to an avg of 3.75V. i see nothing close to that. did you actually measure the voltage or just assume from the label on the charger?
do you have a way to verify the accuracy of the meter?
do not use your battery without a BMS. it is the only protection you have against your inexperience.
do you have a way to verify the accuracy of the meter?
do not use your battery without a BMS. it is the only protection you have against your inexperience.
John in CR
100 TW
Throttles are the 2nd most cheaply made part, second only to the little switches and buttons, yet you haven't ruled out the throttle which could be a loose magnet or something. With the wheel off the ground can you rev it repeatedly and the motor spins up to speed and make it spin and hold at various different desired speeds?
If the throttle is fine, and you proved it's not the BMS shutting it down, then it has to be the controller. If so, there must be something wrong with it, because a 1000W controller is incompatible with the little geared hubbie because it is too powerful and could more easily burn up the motor. There must be something wrong in the controller to trip it's over-current protection at such low power draw....maybe a solder whisker somewhere or a dry solder joint, especially on the shunt, which could make the controller think it's passing more current than it really is.
A poor connection somewhere along a phase wire could have a similar effect, so when too much current passes it heats up the connection and it loses contact enough to make the controller think there's a phase wire fault.
If the throttle is fine, and you proved it's not the BMS shutting it down, then it has to be the controller. If so, there must be something wrong with it, because a 1000W controller is incompatible with the little geared hubbie because it is too powerful and could more easily burn up the motor. There must be something wrong in the controller to trip it's over-current protection at such low power draw....maybe a solder whisker somewhere or a dry solder joint, especially on the shunt, which could make the controller think it's passing more current than it really is.
A poor connection somewhere along a phase wire could have a similar effect, so when too much current passes it heats up the connection and it loses contact enough to make the controller think there's a phase wire fault.
chrashing
100 mW
Thank you for continuing with the ideas and suggestions.
Hello John in CR,
I just inspected the controller soldering, didn't find any obvious shorts. Managed to get it back together without extra parts. Will retry it later this week. I don't expect anything fixed (or more broken.). We had tested with the wheel off the ground, and the throttle worked properly. Had re-connected the connectors, all seemed tight.
Hello Dnmun
Measured the 60V with a meter, while the battery was charging. The 10 year old meter seems good, but has never been calibrated. I though after charging, it is normal for the voltage to drop to 56V or so. Yeah, ok, don't plan to jumper the batter directly to the controller, circumventing BMS the again, that was just a quick test.
Hello Agniusm,
I'm still hoping a couple charge cycles will improve the 3.34V cell group.
The replacement controller is going to take at least another week to arrive. Sure hope it fixes the problem.
Hello John in CR,
I just inspected the controller soldering, didn't find any obvious shorts. Managed to get it back together without extra parts. Will retry it later this week. I don't expect anything fixed (or more broken.). We had tested with the wheel off the ground, and the throttle worked properly. Had re-connected the connectors, all seemed tight.
Hello Dnmun
Measured the 60V with a meter, while the battery was charging. The 10 year old meter seems good, but has never been calibrated. I though after charging, it is normal for the voltage to drop to 56V or so. Yeah, ok, don't plan to jumper the batter directly to the controller, circumventing BMS the again, that was just a quick test.
Hello Agniusm,
I'm still hoping a couple charge cycles will improve the 3.34V cell group.
The replacement controller is going to take at least another week to arrive. Sure hope it fixes the problem.
chrashing
100 mW
Thank you for helping me diagnose this to the correct component. The new controller arrived today. It fixed the problem with the motor cutting out with anything but a light throttle.
Still do not have a technical explanation why the 1000W controller did not work with the 350W motor, but switching to the smaller 500W controller resolved the problem.
I'll keep an eye on the battery cell voltage after I get some charge cycles.
I've learned a lot, and found that I have a lot more to learn.
Still do not have a technical explanation why the 1000W controller did not work with the 350W motor, but switching to the smaller 500W controller resolved the problem.
I'll keep an eye on the battery cell voltage after I get some charge cycles.
I've learned a lot, and found that I have a lot more to learn.
bowlofsalad
100 kW
chrashing said:
Excellent.
Ykick
1 GW
Thanks for the update. Enjoy the ride!
