I turned my 6s lipo into 5s lipo WTF?

[wineboyrider]

I had a pack of 6s 20.8 ah lipo cells together and have been using them fine for around 15 cycles and I accidentally shorted something and saw some sparks etc. Well any way I went to charge the pack and the charger won't let me charge it. So I pull out my volt meter and start checking the big pack and one reads 0v. The total pack voltage is 20v (just like a 5s pack) so I break all the individual packs and every single one of them has a whole cell missing?
WTF? 8) 8) 8) 8) 8) 8)

 

[neptronix]

what did you short? balance cables?

Balance leads can vaporize if that happens.

I had to replace the pins on mine.

 

[neptronix]

or i bet you blew your serial harness.

 

[wineboyrider]

I hope like hell that's what it is, because I would rather replace them than the entire cell(s)! Or maybe I can use the packs as 5s cells?
What about the voltage of the pack?

Shouldn't it have a little more than 20 volts??


I am going to open the pack and test the voltages at the solder points.......?

 

[neptronix]

It is easier to check them with a multimeter at the back of the connector first.
Write down the cell's voltage to find out manually.

add up starting from the black wire.. to the next cell.. to the next cell..

6x 3.00v = 18v, so 20v is within the range of the battery.

Do you remember what you shorted? battery leads or balance leads?

 

[wineboyrider]

I am pretty sure it was the balance leads. A strand of from one of the positive battery leads touched the lvc board. I tried to charge the pack without the balance wires and it still is around 21 volts. All the packs measure the same voltage though and none of them look puffy or anything? 8)

 

[neptronix]

What charger are you using?
And what are the voltage outputs of each cell?

And did you check the voltage at the back of the connector? on my connectors that i fried ( see pic above ) there was visible charring inside but the back of the connector read the correct voltage..

 

[neptronix]

i also bet your charger is seeing it as a 5s pack, am i right?

 

[Philistine]

I am not sure if this is what you have done, but twice I have accidentally shorted one of my 5S packs. Basically the positive and negative wires of one 5S pack touched. When tested with a Cellog, the pack looked like a 4S pack. I opened up the end where the discharge leads come out (on a turnigy pack it is the white end wrapper), and the solder had blown at the end. I just resoldered that blown bit of solder at the end, and the packs are fine now and back to being 5S. If you like I can post photos of what I mean.

 

[Philistine]

This is the blown connection I was talking about, you can see the blob of solder I added. Worth checking anyway. Cheers, Phil.

 

[dogman dan]

I'm a bit confused as to what you mean. You say a whole cell is missing, missing when measured where? From the balance leads?

I turned a 5s into a 4s pack, but when I measured voltage at the main wires, the whole pack was reading 0v, because I'd vaporised a tab and that broke the connection on the series string in the pack. It sounds like you haven't done that, so I guess you melted a balance lead on each pack?

Don't peel the entire shrink wrap off, you only need to undo the top to get at the board and the wires.

 

[wineboyrider]

I'm a bit confused as to what you mean. You say a whole cell is missing, missing when measured where? From the balance leads?

I turned a 5s into a 4s pack, but when I measured voltage at the main wires, the whole pack was reading 0v, because I'd vaporised a tab and that broke the connection on the series string in the pack. It sounds like you haven't done that, so I guess you melted a balance lead on each pack?

Don't peel the entire shrink wrap off, you only need to undo the top to get at the board and the wires.

Nope I did that too. It's just like one of the cells is missing? Must be the last cell that series the pack together or something?
If you charge it without the balance wires my Hyperion asks 5s right?

Neptronik: i also bet your charger is seeing it as a 5s pack, am i right?

Yep. And I have 3 different chargers and they all work fine including my new Hyperion? I pulled the other good 6s parallel pack apart and charged each pack separately so I know the chargers are fine?

Philistine wrote:I am not sure if this is what you have done, but twice I have accidentally shorted one of my 5S packs. Basically the positive and negative wires of one 5S pack touched. When tested with a Cellog, the pack looked like a 4S pack. I opened up the end where the discharge leads come out (on a turnigy pack it is the white end wrapper), and the solder had blown at the end. I just resoldered that blown bit of solder at the end, and the packs are fine now and back to being 5S. If you like I can post photos of what I mean.

Might be what I did, but the last 5s pack I did that I blew a fusable link inside of it. It's still sitting on my shelf but it reads 0v?

 

[Philistine]

I am confused by your last post. So is it reading as 0 volts at the discharge leads, but 5S (ie, 1S short of what it should be, ie 6S) at the balance leads? Because if that is the case, then as Dogman says (which is what I was saying, and showed in my photo) you have probably just blown the solder at the tab. Have you checked that? Open the end and have a look, if so, put some solder over the blown connection of the tab (as in my photo) and you might be OK.

Sorry if I have totally missed or misunderstood what you are saying, but I got a bit confused through the whole thread.

 

[Alan B]

Need to open up one pack and measure the individual cells and see what is going on. If a cell sustained some damage during the short, and then drained all the parallel cells afterwards, then those cells are all likely lost. You could convert them to 5S packs.

Shorting Lipos is not really an option. The wiring and connectors need to be arranged so this cannot happen.

Sorry for your loss.

 

[neptronix]

Allright, so open up the back, record the voltages on the cells, and post pics of the carnage if there are any.

 

[dogman dan]

If reading 0 volts on the discharge leads, you've zapped one of the tabs, breaking the connection. The cell is still good, but it's tab is gone.

At some point, you and I both will be making some new packs out of two toasted ones. I have a good strong soldering iorn now. Maybe some weekend I could drive over and we could have a lipo fix party.

 

[wineboyrider]

I am confused by your last post. So is it reading as 0 volts at the discharge leads, but 5S (ie, 1S short of what it should be, ie 6S) at the balance leads? Because if that is the case, then as Dogman says (which is what I was saying, and showed in my photo) you have probably just blown the solder at the tab. Have you checked that? Open the end and have a look, if so, put some solder over the blown connection of the tab (as in my photo) and you might be OK.

No I meant that I had a different 5s pack and when I fried one of the cells it read 0 volts
My 6s lipo packs all read around 21 volts. And when I hook up any 4 of the 6s lipo packs they all show only 5 cells on the charger. The Hyperion won't let you charge them at all, but my Eco 6 will start to charge and it reads that one cell is 0 volts and stops. What's weird is that it is the same cell in all 4 packs? I will do like Neptronix said and get a reading from the battery itself and the back of the balance leads.

 

[wineboyrider]

I am confused by your last post. So is it reading as 0 volts at the discharge leads, but 5S (ie, 1S short of what it should be, ie 6S) at the balance leads? Because if that is the case, then as Dogman says (which is what I was saying, and showed in my photo) you have probably just blown the solder at the tab. Have you checked that? Open the end and have a look, if so, put some solder over the blown connection of the tab (as in my photo) and you might be OK.

No I meant that I had a different 5s pack and when I fried one of the cells it read 0 volts
My 6s lipo packs all read around 21 volts. And when I hook up any 4 of the 6s lipo packs they all show only 5 cells on the charger. The Hyperion won't let you charge them at all, but my Eco 6 will start to charge and it reads that one cell is 0 volts and stops. What's weird is that it is the same cell in all 4 packs? I will do like Neptronix said and get a reading from the battery itself and the back of the balance leads.

 

[dogman dan]

Gotta be something to do with the balance leads, or plug to balance leads then.

 

[wineboyrider]

Okay I finally had a chance to check all the voltages of one pack. The black and white wire in the middle of the 6s wire harness reads 0.2 volts. All the rest of the cells read 4.10v?
Voltages read fine through the balance wires except? the black and white wires in the middle of the harness?

So what does this mean?
8)

 

[neptronix]

Wineboy, open the pack and read the voltages from the actual cells themselves. It is not too hard to do.
You need to find out of the cell is actually bad or if the balance lead is actually bad. This is the only way to determine it.

 

[wineboyrider]

Wineboy, open the pack and read the voltages from the actual cells themselves. It is not too hard to do.
You need to find out of the cell is actually bad or if the balance lead is actually bad. This is the only way to determine it.

Did that. Cells read the same exactly.
8)

 

[liveforphysics]

Me thinks damaged JST pin.

 

[wineboyrider]

Me thinks damaged JST pin.

JST pin is this the wiring harness pin? If not then it has to be a pin inside the pack right?


Also, I opened up one pack and checked the voltage of each cell and I get the same readings?
Also, all 4 packs?????????

 

[neptronix]

Also, I opened up one pack and checked the voltage of each cell and I get the same readings?

It sounds like you are boned.
You can turn this pack into a 5s pack by removing the offending cell, bridging the gap, and then removing the offending balance leads + rearranging the others.

I would say if a cell is at 0.2v for a few days it is toast. If you try to charge said pack, my suggestion is to stick it on the charger outside and take cover.. lol