Problems with charging (overcharge, voltage increased rapidly over 3.5V)

[MrNatural22]

According to Ampster and SteveS though it can.
Because three of mine did. So maybe the cells are bad? Hmmm.
Just a thought.

EDIT: The powersupply I am using is the LONGWELL 30 volt, 10 amp version.

Anyhow, I am waiting to see from Xuba [who read my chat but hasn't responded] what will be done.

I almost caused an overcharge on my longwei 30v 10a power supply by fiddling with the CV control while charging thinking I could turn it up a bit and luckily I was watching when I had one cell take off and immediately shut things down before the BMS went to cell over voltage and disconnected. I’ve learned to pre set the CV and leave it alone til the current drops to zero.
Then be done. Lucky I caught it quickly.

 

[Deleted member 9967]

I almost caused an overcharge on my longwei 30v 10a power supply by fiddling with the CV control while charging thinking I could turn it up a bit and luckily I was watching when I had one cell take off and immediately shut things down before it did damage. I’ve learned to pre set the CV and leave it alone til the current drops to zero.
Then be done. Lucky I caught it quickly.

Oh no. I was warned about that a LOT. Also I was fortunate enough to read the instructions first AND lots of commentary here in the forum.
Nope, I was smart [for a change LOL ] and I set the voltage BEFORE attaching ANY of the wires.
Oh yeah, someone here set it after they added the wires and got a bloated cell. A very powerful warning in picture form.

So yeah, the power supply was never touched after it was set.
I am kind of smart that way LOL. Only took me 60 years or so. ?

EDIT: Again for the newbies. Set the powersupply BEFORE you attach ANY wires. And then LEAVE IT ALONE.

 

[Ampster]

If mine had not warned me then the vent would have popped and my place would be filled with lithium powder etc. Not pleasant at all.

Years ago, I had a 10 Ahr Headway vent and all I got was a whiff of ether.
Back to my original question? Let me suggest we try to find out why your BMS set off alarms but did not stop charging. What can you tell us about the BMS?

 

[Sharky722]

EDIT: Again for the newbies. Set the powersupply BEFORE you attach ANY wires. And then LEAVE IT ALONE.

I second that, do not fiddle with psu while connected.
Were you charging is series or parralel?
I didn't think a bms works in parallel connection or did I just learn something? Or monitoring cell voltage with something.

 

[Just John]

According to Ampster and SteveS though it can.
Because three of mine did. So maybe the cells are bad? Hmmm.
Just a thought.

EDIT: The powersupply I am using is the LONGWELL 30 volt, 10 amp version.

Anyhow, I am waiting to see from Xuba [who read my chat but hasn't responded] what will be done.

If you have them in a pack without a BMS, it is a dead cell waiting to happen. The BMS should shut off charging when any cell hits 3.65 volts.

 

[Ampster]

The BMS should shut off charging when any cell hits 3.65 volts.

To me the issue is, why that did not happen. The buzzer and lights went off but the charger did not stop when the alarms went off. The solution is to find a way to turn off the charger. It could be done by using the same signal that turned on the lights and buzzer to turn off the charger.

 

[Just John]

To me the issue is, why that did not happen. The buzzer and lights went off but the charger did not stop when the alarms went off. The solution is to find a way to turn off the charger. It could be done by using the same signal that turned on the lights and buzzer to turn off the charger.

Yes, not a problem with the cells. The BMS is either set wrong, or doesn't know how to stop the charger. If the BMS is a Chargery or sbms0 (and many others), you have now learned why the FET based BMS are popular. I am not sure this is a vendor problem.

 

[Deleted member 9967]

No relays so no stopping.
The BMS let out a warning sound.
As I was right beside it I literally pulled the plug.
Not all BMS come with relays.

 

[Deleted member 9967]

To me the issue is, why that did not happen. The buzzer and lights went off but the charger did not stop when the alarms went off. The solution is to find a way to turn off the charger. It could be done by using the same signal that turned on the lights and buzzer to turn off the charger.

I turned the switch to the "off" position. It took seconds.

 

[Deleted member 9967]

I mean, I did type out a long statement. So did anyone read it or no?
Or should I just say the heck with this and leave?
Oh well.

 

[Ampster]

No relays so no stopping.
The BMS let out a warning sound.
As I was right beside it I literally pulled the plug.
Not all BMS come with relays.

I turned the switch to the "off" position. It took seconds.

Okay, then you are the relay. I think I understand some of the history. Two questions:
Did you notice the pack voltage when that happened or just before that happened?
Do you have a link to the BMS you are using and a diagram or picture of how it is set up?

 

[Ampster]

I did type out a long statement. So did anyone read it or no?

I have read and understand the history. Do you agree that the issue is that the BMS did not turn off the inverter like most BMSs typically do? That is the problem that I am trying to help you solve.

 

[Deleted member 9967]

Okay, then you are the relay. I think I understand some of the history. Two questions:
Did you notice the pack voltage when that happened or just before that happened?
Do you have a link to the BMS you are using and a diagram or picture of how it is set up?

Actually I have videos of it.
I will again post a link as it was lost in the other thread.
https://www.youtube.com/channel/UCz2CSFMvzJL_gPr-eWj-qpA

 

[Deleted member 9967]

I have read and understand the history. Do you agree that the issue is that the BMS did not turn off the inverter like most BMSs typically do? That is the problem that I am trying to help you solve.

What inverter? I never have owned nor wish to buy an inverter. So no clue what you are talking about here.
I never even mentioned an inverter in the LONG part I wrote about all of this earlier either.

 

[Deleted member 9967]

Ok just to reiterate in short form once again.
Essentially I was charging it to 3.5 volts. I started it the power supply and set it. Then I plugged in the wires.
Then I turned to my computer. Then an alarm went off and literally as I was turning the power supply off the cells went up to 4 volts and more.
It took seconds.

 

[Ampster]

What inverter?

I meant charger.

 

[Ampster]

Ok just to reiterate in short form once again.

I understand the history. I can only help you, if i understand what BMS you are using. Can you answer the question?

 

[Deleted member 9967]

I meant charger.

The BMS is iSDT BattGO [<--Note: this is not a BMS]
The charger or power supply is the Longwei 30 volt 10 amp

 

[Ampster]

The BMS is iSDT BattGO

Like this?

Amazon.com

 

[Deleted member 9967]

Like this?

Amazon.com

Yes