Top balance mistakes could use some help

[Carpslinger]

I received 12 genfang 100ah cells and they were at 2.7 to 3.1v. I put them in parallel and used a bench charger set at 3.65v and 10amps. When positive and negative leads attached, the volts went to zero and the amps to 13 and watts were zero. After one day, they volts went up to 1.6 volts on the bench charger and the amps went down to 10.7, and the watts started to climb. Not sure what was going on, I removed the bench charger and found the all my cells were all at 0.1 volts. Did I just kill these cells? What did I do wrong? Please help

 

[Pyrofx]

Check polarity. On batts black is positive.
Did you get one backwards when paralleling?

 

[Carpslinger]

This I did not do. Any chance I was supposed to readjust the voltage after I connected the bench charger? At this point how do I recover my cells?

 

[Pyrofx]

Never adjust after connection. Are your volt readings with vom , or the charger ?

 

[Carpslinger]

Never adjust after connection. Are your volt readings with vom , or the charger

 

[Carpslinger]

Did not adjust. Used a vom on each cell. All at 0.1v now

 

[Carpslinger]

Is my bench charger faulty?

 

[Carpslinger]

I was thinking about putting them back in series and onto the charger with the BMS installed. Not sure how to recover these new but dead cells.

 

[MisterSandals]

Can you share a pic of how you had he batteries wired while charging in parallel?

 

[mikefitz]

When positive and negative leads attached, the volts went to zero and the amps to 13 and watts were zero.

That does not sound too good, either faulty power supply, incorrect connection, one or more bad cells.
I suggest disconnecting the cells from each other and testing/charging one at a time.
Before you reuse the power supple test its performance on a suitable load, if you have nothing available use a car 12v bulb.
Receiving a cell at 2.7 volts seems a little near the limit in my view.
My personal viewpoint is that each cell should ideally be evaluated individually, charged as a single cell.
Connecting many cells in parallel to 'top balance' without experience and adequate equipment may lead to damaged cells.

Mike

 

[Carpslinger]

That does not sound too good, either faulty power supply, incorrect connection, one or more bad cells.
I suggest disconnecting the cells from each other and testing/charging one at a time.
Before you reuse the power supple test its performance on a suitable load, if you have nothing available use a car 12v bulb.
Receiving a cell at 2.7 volts seems a little near the limit in my view.
My personal viewpoint is that each cell should ideally be evaluated individually, charged as a single cell.
Connecting many cells in parallel to 'top balance' without experience and adequate equipment may lead to damaged cells.

Mike

Great plan. On it!

 

[RCinFLA]

The cheap 30v 5/10amp switching power supplies are not the greatest quality. Whenever a new one is first used you should carefully watch it for first several hours of high current use to make sure it does not blow out.

Once it has some history of heavy current load use you can have more confidence in it to leave it unattended..

 

[Carpslinger]

Great plan. On it!

Set the bench charger at 3.65v 10 amps and cell did not charge. This is what the charger displays. Are they ruined? Any suggestions?

 

[mikefitz]

You may have the cell incorrectly wired. see comment on post #2 and drawing from cell data


Mike

 

[Carpslinger]

You may have the cell incorrectly wired. see comment on post #2 and drawing from cell data

View attachment 67538
Mike

Holy smokes. Black is positive. Never thought this was possible.

 

[Pyrofx]

Holy smokes. Black is positive. Never thought this was possible.

FFS. Did you not read what I said in post 2 ? You said this I did not do .

 

[Carpslinger]

FFS. Did you not read what I said in post 2 ? You said this I did not do .

I read it but I couldn't believe what I was reading I guess! I think he was just relating with a lot I was reverse Polarized and just glossed over the black is positive as I could never imagine that in wirings things. Do you think I destroyed these cells?

 

[Carpslinger]

FFS. Did you not read what I said in post 2 ? You said this I did not do .

I read it but I couldn't believe what I was reading I guess! I assumed you were asking if I was reverse Polarized and just glossed the black is positive as I could never imagine that in wiring dc. Thanks for posting twice. You think it's a good chance I ruined the cells by trying to balance them with reverse polarity?

 

[Carpslinger]

Did you test the cells before attaching a power supply? We should always test our cells when we start to work with them. What does the tester say when you attach it correctly?

I did test them but couldn't imagine them being a negative voltage and didn't pay attention to the negative sign at the very very upper corner of the voltmeter as I couldn't even believe that would be a possibility that red is negative and black is positive

 

[mikefitz]

You think it's a good chance I ruined the cells by trying to balance them with reverse polarity?

I would guess so. Have you measured the voltage on the rested cells?
You could try connecting a cell to the charger set with a low voltage and see if it accepts a low current. If it does, gradually increase the voltage and current. Kind of clutching at straws.

Mike