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Discussion Starter · #1 · (Edited)
Hello!

We are working on an electric boat that is powered by 82 100 Ah Cells from Thunder Sky. We also use the BMS 100 from Thunder Sky and a charger.

So far we have connected all the cells with the BMS and they all are shown in the Display and balancing works.

But we always have the error "invalid node warning" and I don't know what to do to solve this problem.

I tried to remove all the Cells and to remove all the collecting modules, but its very strange that the the error does not go away.

I measured the cable, it ok, we have all cells in the list of the BMS on the display, the current sensor works, but we cannot charge and use the batteries because we have this strange error and the charger is switched off by the bms because of the error.

Has anybody also a BMS from TS in use and knows about that problem?
Thanks for your advice,
Best Regards from Austria,
Hermann
 
G

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I don't know what to do to solve this problem.
Remove the BMS Oooops (BS) System. Until you figure out what is happening. If you leave it connected you risk a big loss. Is there a short in one of the modules? Wires?

Pete :)
 

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Discussion Starter · #3 ·
Hi,

I have tried to figure out the problem.
I checked all cables, they are ok, no short circuit, not broken.
I tried all 10 collecting modules, its always the same.

I unplugged all collecting modules, took one after the other, set the bus chanel to 0-0.

When I start the controller without any collecting module, it says low voltage warning which is because there is no collecting module.

When I plug in a collecting module and enter the amount of cells, the display shows the cells (each voltage) and the red led on the collecting module is blinking.

After some seconds the controller starts the node invalid warning alarm......

I dont know what to do now....
Should I send it back to Thunder Sky?

I removed it from the cold garage and put it for some hours in a warm room, maybe its because of the humidity that it has an internal short-circuit.....

Thanks.
 

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Are you not getting support from TS or your distributor where you bought it? I worked in industrial electronics for decades and if you're not able to get tech support from them that's not good at all! Any reputable company has a good support system.

I'm considering TS cells but haven't decided yet. Still doing my due diligence...
 

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Can you lead me to some links about the Thunder Sky Battery Management System 100? I'm finding very little info about it. I didn't find a mention of it on the TS site, I was hoping to find instructions or pdf manuals there (they have quite a bit of info about their batteries posted.)
 

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It looks to me like that unit will be very picky about programming. The number of nodes has to be set and match what is found or it will toss a "Nods invalid alarm" [sic]. This could be programming, a single bad node, or something wrong with the head unit not "reading" correctly.

This could be hard to figure out as the company is still in the "Engrish" phase of providing documentation. It is not all that easy to read or perfectly clear (probably makes great sense in Chinese but that doesn't help me.) I would recommend a careful reprogramming in case something was missed and see where it goes from there.

I tend to be a BMS (no spaghetti allowed) guy myself but I am leaning toward Pete's advice. Don't allow cells to be hurt while trying to figure this out.
 

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Discussion Starter · #8 ·
Hi,

Yes, I think this too.
As the BMS can be used from 1 cell up to a few hundred I tried to get it run with 10 cells (=1 collecting module). So I just have one cable and this is free of short-circuits.

As one collecting module gets 14 small cables from the batteries (12 from cells and 2 from temperature sensor) this means that communication musst be ok when I see the temperature and all 10 cells in the display.

Why do you think cells could be hurt?

At the moment the cells are not connected to the collecting modules and there is no power supply for the controller.

The strange thing is that balancing works, so when all modules are connected, they balance all cells to the same value.

But I cannot charge the cells because the controller sends the node invalid warning also to the charger and this is turned off.

We charged the cells a few days ago by cutting the comunication between charger and controller to about 80% because we had to test the complete system on that day because of mounting the electric engine.

Now I wanted to let the bms take over control of charging, but this doesnt work because of this error.

So, as I said, all cells are at the moment at 3,38 V.

I hope I get an answer from China regarding this problem and I am thinking about charging the cells for another hour with 20 A and let the bms balance the cells after that before shipping the controller to them, so that we can do another test with nearly fully charged cells.

On the other hand this could be not good for the cells when the bms cannot turn off the controller because of a high delta voltage of some cells......
 

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Why do you think cells could be hurt?

At the moment the cells are not connected to the collecting modules and there is no power supply for the controller.

The strange thing is that balancing works, so when all modules are connected, they balance all cells to the same value.
If the cells are not connected to the collecting modules then I don't see any how the BMS can hurt the cells (or be a BMS in that condition. :))

The balancing works even though the BMS isn't quite working? That is where I start to get concerned. Electronics that half works sometimes do strange things. If it is hooked up please make sure it isn't draining the cells to quickly or unevenly. A BMS represents a full time load (small one, but still a load) on the pack so you may need to charge occasionally to maintain the pack.
 

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Discussion Starter · #10 ·
Yes, thats the strange thing.

When I connect all modules with batteries and the modules with the central controller everything works as it should (all cells, all temperatures on display, all red LEDs are working, the cells are getting balanced...) but I get the node invalid warning error which does not allow charging. So charger is reducing output to 4,3 Amps which would take me 3 days or something like that to charge the cells.

As we have more than 320 V in the system and a 8 kW charger, I only use it when I do some other work next to the car because I fear that something could happen and there are a lot of other expensive vehicles next to ours in the garage....

So now everything is disconnected.
So I think the cells are safe in this situation.
 
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I stopped the charge because a few batteries were in the 4 volt range. So our used pack which was originally charged with a BS system is way out of balance before the charge is even close to being done. Some batteries are just a bit over what the starting voltage was and about 8 have reached into the 4 volt range. Ouch. So I now must discharge and bottom balance all 34 batteries before I continue. Will start the photo album when we get our batteries in sync with each other.

Pete :)
 

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Discussion Starter · #12 ·
Hi again,

Finally I found the problem, it was a wrong bus adressing of one collecting module.

Now I have a question regarding the charging.

What is the best way to charge the batteries?
My charger is connected to the first and the last cell and provides a current from 0 to 23 Amps (can be choosen).

Yesterday I started charging with 17 Amps, then I tried little bit more.

It was the same like gottdi said, one cells reached 4,3 Volts when the lowest one hat 3,4.

So I unplugged the charger and over the night the BMS balanced the cells.

I did not had a look now, but I think they should all be round 3,3 or something like that now.

So whats the best Current for charging?

This would take a long time to get all of them on the same level....
The cells are new and it the first time i charge them....

Thanks.
 

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I have the same BMS that you have and the balances are not cells.
The charge of one of the cells at the top also turn it off the charger.
 

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Hi again,

Finally I found the problem, it was a wrong bus adressing of one collecting module.

Now I have a question regarding the charging.

What is the best way to charge the batteries?
My charger is connected to the first and the last cell and provides a current from 0 to 23 Amps (can be choosen).

Yesterday I started charging with 17 Amps, then I tried little bit more.

It was the same like gottdi said, one cells reached 4,3 Volts when the lowest one hat 3,4.

So I unplugged the charger and over the night the BMS balanced the cells.

I did not had a look now, but I think they should all be round 3,3 or something like that now.

So whats the best Current for charging?

This would take a long time to get all of them on the same level....
The cells are new and it the first time i charge them....

Thanks.
Are you bottom balancing? If so explain how you do it.
 

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Discussion Starter · #15 ·
I have the same BMS that you have and the balances are not cells.
The charge of one of the cells at the top also turn it off the charger.
So you think there is no balancing funktion in the system?

I dont know exactly, I charged the 82 cells with the charger and when the charger says fully charged we have 317 Volts. The highest voltage is 4,6 V and the lowest is 3,6.

What is bottom balancing?
 

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So you think there is no balancing funktion in the system?

I dont know exactly, I charged the 82 cells with the charger and when the charger says fully charged we have 317 Volts. The highest voltage is 4,6 V and the lowest is 3,6.

What is bottom balancing?
Are you saying you don't know if they're balanced? IF you have 4.6V on a cell you're in the danger zone friend! That ain't good AT ALL! It's recommended not to exceed 4V.
 

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Discussion Starter · #18 ·
Ok, we charged the battery pack again.

Now I set up that the charger should turn off when one cells reaches 4 Volts.
I have tested it, it works, when one cell reaches 4 Volts, the charger reduces the current to 0.

So know we have after 2 cycles the highest cell with 4 volts and the lowest with 3,36.

When the voltage was 3,2 all cells had the same voltage during the charging process.

As we have a small problem with our motor, we cannot use it, so I will let the BMS work and tell you about the voltages in the next days.....

Thank you very much for your answers!
 

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Why are you using a BMS system? What do you want it to do for you?


At 3,35 - 3,78 V your pack is full and ready to use. Don't worry about the apparent "imbalance" of your cells, they really are all at 100% charge or near. These batteries change voltage rapidly at their extremes.

I think you need to study how these cells behave to get a better understanding of your power system. Watch some of the videos on evtv.me about battery testing.
 
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