Need help - 24s headways death...

Hello, I almost finishing my build ( relation in this topic: http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=34052).
Two days ago first time was riding. Few km only.
Then back and charging first time.
I have Chinese bms and charger 2A. About one hour charger stop bulking. was on only time to time. When the charger was on voltages on the cells was growing. Even up too 3.9 V per some cells. Then charger was stoping and voltages were decreeing to about to 3.65 to 3.7 on the most charged cells. BMS was warm. So this looks like all was ok.Im were worrying to lost charging process alone on this first time so I stopped and go to sleep.
After two days was a time when I ride again few km. Then have a free time, so start charging and keep on eye on bike. After one hour when charger didn't off I checked voltages on the cells. On few was up to 4.1V! I stopped charging. Last cell (mine plus site) has a less then 1V. After a little time almost 0V (0.1V)....
SO what whose that? Bad headway cell? Bad bms? Why bms didn't stop charging process? In specification was writing that max overvoltage protection is 3.9V per each cell. What's goes wrong?
I tried to charging only this one 0.1V cell using other rc charger but notching. After few seconds when charger stopped charging process on the cell is again 0.1V...(Used ni-cd program in-spite of charging from 0V)
Should I worrying about other cells? This bad cell could drain current front others? rather not but...
Sorry if some my questions are lame, but this is my first time with bms systems and this kind of charging... Before using only rc chargers and then was always all ok...
Regards, Mike.

You have to charge the all the cells that are below 2V quickly!! You have to use a bench power supply or a multi battery type lipo charger. If you have none of this place 2 cells in paralel, the one that is below 2v and one fully charged, the voltage will rise in the lower voltage cell.
I have tryed several of those BMS and none of them worked! I have 2 of them that are always bleeding one cell. This is one of the reasons that might take that cell to 0.1V . You will need a voltmeter to test the bleedind resistors to know what cells are being drained. You mostlikely have a faulty BMS.

Well yes I checked each cell's voltage. Only last cell (on this time) has a voltage under 2V (exactly is 0.1V). This is the last cell in all configuration its mean main plus ended cell. I'll try to charging today again this cell.

Because cannot using any other program in my lipo charger then nicd/mimh started on this but about 200mah charger stopping because probably voltage dropping to 1.6V. After stop pomping current cell's voltage dropping in few seconds to 0.1V again. So I do not have a time to reconfiguring charger to charging 2V pb program. So Parallel my small li-ion charger and li-ion 18650 cell with headway cell. Voltage quickly dropping to about little more then 2V on each cell (yes I now, is possibility than I kill li-ion small cell). So I have a option (voltage over 2V) to start charging simultaneously using my lipo charger (used of course life setup).
Charger starting. I decided to used about 0.3C rate current (its mean 3.5A about). Yes I know that is to much for bad cell witch low voltage but can not charging all the time parallely with small li-ion cell (as on the foto). This current must be so big, because when I take off small liion cell and his small charger, voltage on the life headway cell dropping strongly (with smaller currents less then 2V... so charger automaticly stopping). Even using this current to charging (3.5A) Voltage regularly, slowly dropping down. After stoping charging in few minuts voltage on the bad cell again dropped to 0.1V... SO what now? Try again with a little more current and more charging time? So my bms is shitty, yes? whats now? I can buy next (but for this money I could bought two lipo chargers as I have one and using to charging and balansing this...)but no guaranty that this new one will be okey... (

Remove the low voltage cell from the Headway Pack and make a paralel with another Headway cell also removed from the pack. Let the paralel stay for 3 or 4 hours and let me know the results.

>So my bms is shitty, yes? whats now? I can buy next (but for this money I could bought two lipo chargers as I have one and using to charging and balansing this...)but no guaranty that this new one will be okey...<

i suspect the cell is so low the charger will not charge it. if you discharged it to this level it is most likely dead.

if it reached this level from sitting unused, it may recover.

why is your first assumption that the BMS is bad? do you say this from lack of knowledge of BMSs in general or is there something specific about your BMS that caused the cell to be discharged to .1V? you used the term "chinese" in your other thread as though that meant you can label it broken without any investigation. a racial bias that affects your decision making perhaps. do you realize that all the BMS are made in china? along with everything else we use these days. i doubt if it is defective, more likely just poor practices on your part led to the death of the cell, not from the BMS.

where are you measuring the voltages? you can put any other dc source on the cell to charge it, even use a cellphone charger to push charge into it.

Okey, cell is dead. I was trying charging again using lead acid acu and 21W bulb, so it gived about 1.75A current on the cell. After few hours the same situation. Stop charging - voltage on the cell drop to 0.

i suspect the cell is so low the charger will not charge it. if you discharged it to this level it is most likely dead.

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Of course - I told about it. And wrote how start charging by used parallely other li ion cell and charger to upgrading start voltage for lipo charger.

why is your first assumption that the BMS is bad? do you say this from lack of knowledge of BMSs in general or is there something specific about your BMS that caused the cell to be discharged to .1V

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Read the story in first post - First charging and balansing looks like all will be okej. Its mean when on the one of cell voltage was more then limit (about 3.9 as I measured) charger stopped, bms resistors was warm and voltage on the cells dropping down. After time charger was starting and voltage on cells growing - and again all process (limit voltage cut off charger dropping cell Voltage). That was the first time. Second charging - after hour was measured voltage on the cells and on the few was more then 4V. So I was cut off charger (steal worked and chargin inspite of bms should cut of it) Then measure all cells and on the las voltage was low. So cut off bms board. But voltage on this cell permanently droped down to 0.
The question is why on this second time charger bms not cut off charger?

ou used the term "chinese" in your other thread as though that meant you can label it broken without any investigation

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No its mean for me that this bms was made in China and was offer on some China location shop. For example I see bmses on the german sites etc. I do not remember exactly what type it is so called: "chinese". Not label as broken, that was a question.

a racial bias that affects your decision making perhaps

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Thats only your interpretation this part of this story - that's yours OPINION, not a fact.

o you realize that all the BMS are made in china?

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What do you expect? Yes I understand that probably most world electronics are made in china. So what?
All bms? this projected on this forum is made in china too? I do not understand when do you want to go in this discussion?

i doubt if it is defective, more likely just poor practices on your part led to the death of the cell, not from the BMS

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Yes? So Okey, help me and told what poor practices I do on this bms?
You know man (or a woman), I could be thinking you suggesting that I'm a racist, than that I not too smart and can't read instruction. Even if its true, and I not so familiary with bms please do not exploit this fact to proving that bms is good. This is the same opinion kind, like that the bms is bad but in other site of looking.

The Facts are: In this situation it will be three possibilities:
Bad BMS
Bad Cell
Bad connection

And still not working bike

where are you measuring the voltages

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Between cells? I do not understand...