Victpower battery pack after 1 year

[wb9k]

I'm just guessing but the cells are from a recall 2yrs. a more ago and where sent to China for recycle and some of the best ones were sold early. The days of 18.50 usd cells that work is ?

No, that is not what happened, nor is the time frame correct. The campaign was about 1 year ago now. None of those cells were supposed to ever end up in China. We have recycling here in North America. Shipping scrap to China would have made no sense at all. Any recalled cells that got to China should be considered stolen.

 

[Ishikawa]

A year ago, I bought a pack of these cells for my scooter from OSN-power (16S-3P)
After half a year of operation began problemmy.
First two cells were swollen. I replaced them. Then swelled another cell.
I also replaced the damaged cell.
After that, I took apart the battery for a new project, Battery for Vectrix scooter.
I bought another 36 cells to complete the project. 42S-2P
Yesterday, I finished making the battery. Check internal resistance and voltage of all cells. Charged the battery and did test drive on Vectrix scooter.
The next day, I again found the inflated cell.
I always use BMS and the cells were never overcharged and never overdischarged.
On the old and the new scooter, I use different BMS.
I spent a lot of money these cells, time and effort.(82 cells)
I am very upset.

Sorry to hear your problem. I just wonder if you checked all of cell voltage before and after the charge? You have a BMS with the pack so I suppose you never balanced the pack, is it correct? Did you check cell voltage sometime to ensure if BMS is working correctly?

 

[999zip999]

I put mine in set's of 6 cells and parelle charged to 3.65v. after a couple days they where close and build the pack. Caveman is as Caveman does.

 

[yokneamcity]

A year ago, I bought a pack of these cells for my scooter from OSN-power (16S-3P)
After half a year of operation began problemmy.
First two cells were swollen. I replaced them. Then swelled another cell.
I also replaced the damaged cell.
After that, I took apart the battery for a new project, Battery for Vectrix scooter.
I bought another 36 cells to complete the project. 42S-2P
Yesterday, I finished making the battery. Check internal resistance and voltage of all cells. Charged the battery and did test drive on Vectrix scooter.
The next day, I again found the inflated cell.
I always use BMS and the cells were never overcharged and never overdischarged.
On the old and the new scooter, I use different BMS.
I spent a lot of money these cells, time and effort.(82 cells)
I am very upset.

Sorry to hear your problem. I just wonder if you checked all of cell voltage before and after the charge? You have a BMS with the pack so I suppose you never balanced the pack, is it correct? Did you check cell voltage sometime to ensure if BMS is working correctly?

Before assembly, I checked the internal resistance and voltage in each package. Then charge each cell separately to 3,6 volts using Icharger.
Mini BMS turns off the charger at a voltage of 3,6 volts per cell.

 

[dnmun]

what did you use for the BMS that allowed it to blow up the cells?

 

[dnmun]

usually puffing follows over discharge or over charging. that was why i asked him to let us know what BMS he was using so we can recommend people avoid it.

 

[yokneamcity]

I use the mini BMS in my Vectrix battery project.

 

[dnmun]

what is a mini BMS?

 

[999zip999]

I would run a second set of balance or sense wires so you check with a cellog.
What cells did you buy Full tab usa or half tab or ???

 

[cwah]

what is a mini BMS?

This is the mini-bms:
http://minibms.mybigcommerce.com/

 

[cwah]

I decided not to desolder the cells as this is impossible. I cut the swollen cell and the deformed one:

Now my pack is much smaller with 18 cells only. There is still one cell that looks a bit damaged (cell number 4 from the right) but as it has correct voltage I'm leaving it on it for now.


Now I have a 20s BMS and 18 cells:

Any way I can configure the BMS to have it work on 18 cells?

 

[cwah]

I decided to copy Agnisum and have a pressure strap made of wood board with my battery pack:

Closed case will look like this:

Next step I'll have to discharge the pack in order to have minimum cell size, tighten the bolt and that should be it!

 

[dnmun]

you can open the BMS so we can inspect ti to see if there is a way to hack it to 18S but the cell you saw that has the mylar shorted to the electrode is not gonna last long like i said so you may find it easier to just go directly to 16S, buy a new 16S BMS and then rewire the sense wires. i think this is the fourth time i tried to explain.

 

[cwah]

ok ok, I'm going to remove this cell and see how that goes. I'm staying with 17s for now until I have a new BMS

 

[dnmun]

first take the heat sink off the BMS and post up a picture so we can see if it is possible to hack it to 17S, or 18S. i think it uses the digital controller for HVC and LVC and i have not figured out how to hack them yet.

 

[cwah]

Here is the picture of the BMS:

 

[cwah]

Finally amputated my pack

 

[dnmun]

yes, we can hack that one.

you only need the small soldering iron and remove two of the tiny resistors in the HVC and LVC signal lines.

you can use the current sense wires up to the #17. make sure they are all in series and double check each spot on the sense wire plug, to be sure they increase in series of voltages as you move up the plug, before you plug it into the BMS after you rewire the top sense wires.

i think most of the ones you cut out were close to the top so you should only have to move a few sense wires with your soldering iron.

for the cells that you cut out you can solder a heavy wire across the space where that cell is missing.

 

[cwah]

I added a jumper for the missing cells. Connections are not very strong because it was impossible to solder on aluminium. I had to directly use the solder from the sense wire :lol:

So you say for the BMS, all I have to do is to desolder the HVC and LVC resistors? I can't see where it is in the signal line??

And also, how shall I remove this yellow board? It looks to be glued? Shall I force to open it?

 

[999zip999]

Cwah this is now a hobby battery and use like it. Charge and kepp outside as may be a little problem with high power cells and be careful.

 

[dnmun]

not sure what the yellow board means but the resistor you need to unsolder if you are down to 17S is R187. there appears to only be one signal line there for both the LVC and HVC since that is the only row of resistors i see.

i assumed you would be able to solder to the solder that was present already. you have to be certain the sense wires are correctly rewired before connecting the BMS to the sense wires again. check the cell voltages on the sense wire plug and verify they increase sequentially.

 

[cwah]

I mean the yellow pcb board just below the green one. I can't find any screw. I suppose it is glued and to remove I have to force it?

And do I only desolder the R187? Once done, is there still the HVC and LVC?

 

[dnmun]

i have no idea why you need to remove the yellow board. it does appear that the only signal line is the one on top so i am assuming that removing R187 will prevent it from shutting down the BMS for HVC and LVC.

again i warn, do not connect the sense wire plug until you confirm the voltages increase sequentially by one cell voltage on each pin of the plug.

 

[cwah]

but I need to remove the yellow board in order to desolder R187 isn't it? I can't directly do it from the top of the board I suppose?

 

[agniusm]

Sorry mate, but i must say, your box looks terrible. I know you put some work into it but you have to have another go at it.
the material i would like to use is glass epoxy sheet, at least thats whats it called in EU. It looks like this: http://www.labara.cz/hu/laminalt-szigetelanyagok/technical-laminates-sheets/153-sklotextit-g11-180dc
If you could get 2 sheets cut to 223x162mm then grooves routed for your ties, say 6mm deep in 10mm material. Get aluminum sheet, 1mm x 700mm x thickness of your pack with compression plates. Bend it twice so the whole pack slides in. Use some kapton tape on aluminum inside. Drill few 2mm holes on aluminum to secure it to the glass epoxy sheet.