unbalanced cells and charging?

[BobbyMac]

After the obligatory 3 month wait, I finally have my first Ali shipment. I bought a 200ah pack but the cells are at 3.2v and 3.1v while the 2 others are at 1.2v and 1.3v. What do I do? Do I assemble the cells and BMS and attempt to charge? I have a Victron charger. Should I arrange the cells in any particular way like the lower charged cells at the + and - ends? Links and advice are greatly appreciated....

 

[John Frum]

After the obligatory 3 month wait, I finally have my first Ali shipment. I bought a 200ah pack but the cells are at 3.2v and 3.1v while the 2 others are at 1.2v and 1.3v. What do I do? Do I assemble the cells and BMS and attempt to charge? I have a Victron charger. Should I arrange the cells in any particular way like the lower charged cells at the + and - ends? Links and advice are greatly appreciated....

If those are LFP cells you should seek a refund.
2.5 volts is dead empty.
If you decide to keep them.
Charge them individually at very low amperage until they get to 2.5 volts as measured at the battery terminals.
After that you can turn up the amperage.
Then capacity test each cell.
Then let the individual cells sit full for up to a month to see if they hold a charge.
They will naturally settle quite a bit in the first 24 hours and very little for the rest of the month.
Record you findings.

 

[Bubba1]

Bummer.

 

[time2roll]

If you want to test the cells, parallel charge the set to 3.65 volts together.

 

[John Frum]

If you want to test the cells, parallel charge the set to 3.65 volts together.

@BobbyMac please don't do this.
The low cells may short internally during the first charge.
If you connect them in parallel you risk the rest of the cells.

 

[time2roll]

If those are LFP cells you should seek a refund.
2.5 volts is dead empty.
If you decide to keep them.
Charge them individually at very low amperage until they get to 2.5 volts as measured at the battery terminals.
After that you can turn up the amperage.
Then capacity test each cell.
Then let the individual cells sit full for up to a month to see if they hold a charge.
They will naturally settle quite a bit in the first 24 hours and very little for the rest of the month.
Record you findings.

There is a time limit to requesting a refund. Need to cram this into 7 days or less.

 

[Steve_S]

PLEASE don't connect those together in Parallel ! Get the two UP if possible to 3.200, then the others can be connected and again, slowly to 3.400 full saturation (taking 1A or less) then push up to 3.600-3.650 and saturate again.

Honestly the two cells that are below 2.500 should have Stayed in China.... this does not bode well for the other cells either as they could be anything. Typical Battery Broker bulk cells. You should also share this experience openly, link to POOR Vendor & Product they flogged at you to help prevent others from getting phookered.

 

[BobbyMac]

 

[BobbyMac]

I requested a refund. We will see.... so what to I do with 100ah 6v battery?

 

[time2roll]

I expect the seller will simply say to charge the cell and put it in service. Good luck.
The money hurts but it kills to start the 90 days over. Sorry for the trouble.

 

[BobbyMac]

If those are LFP cells you should seek a refund.
2.5 volts is dead empty.
If you decide to keep them.
Charge them individually at very low amperage until they get to 2.5 volts as measured at the battery terminals.
After that you can turn up the amperage.
Then capacity test each cell.
Then let the individual cells sit full for up to a month to see if they hold a charge.
They will naturally settle quite a bit in the first 24 hours and very little for the rest of the month.
Record you findings.

I have a meanwell variable voltage AC to DC charger but it puts out 23.3A. What type of charger should I get. BTW, I got a refund for 2 of the cells.

 

[John Frum]

I have a meanwell variable voltage AC to DC charger but it puts out 23.3A. What type of charger should I get. BTW, I got a refund for 2 of the cells.

23.3 amps is ok.
You mention charger, does that mean it supports charge termination?
Or is this a power supply?
Please post a product link.

 

[Steve_S]

One thing about Meanwell and other power supplies like that, far too often people undersize the wire for the amperage they can deliver, even if it is slightly warm, it's too thin, you need real wire & real connections, those Aligator Clips are plain and simple Evil.

 

[BobbyMac]

23.3 amps is ok.
You mention charger, does that mean it supports charge termination?
Or is this a power supply?
Please post a product link.

MEAN WELL original LRS-350-15 15V 23.2A meanwell LRS-350 15V 348W Single Output Switching Power Supply https://www.amazon.com/dp/B06VYDWKL...abc_5AA6DHB215MBB4YCGACZ?_encoding=UTF8&psc=1

 

[BobbyMac]

One thing about Meanwell and other power supplies like that, far too often people undersize the wire for the amperage they can deliver, even if it is slightly warm, it's too thin, you need real wire & real connections, those Aligator Clips are plain and simple Evil.

I'll use 10gage because I have a ton of it.

 

[John Frum]

MEAN WELL original LRS-350-15 15V 23.2A meanwell LRS-350 15V 348W Single Output Switching Power Supply https://www.amazon.com/dp/B06VYDWKL...abc_5AA6DHB215MBB4YCGACZ?_encoding=UTF8&psc=1

ok its a power supply.
Assuming its a constant current, constant voltage power supply you can use it to charge your cells and your battery as a 12 volt nominal pack if you have a 4s bms.
The power supply doesn't do charge termination so It won't terminate the charge on its own.
As I said above If you have the time I suggest your charge and capacity test each cell independently.

 

[BobbyMac]

ok its a power supply.
Assuming its a constant current, constant voltage power supply you can use it to charge your cells and your battery as a 12 volt nominal pack if you have a 4s bms.
The power supply doesn't do charge termination so It won't terminate the charge on its own.
As I said above If you have the time I suggest your charge and capacity test each cell independently.

I am going to try and charge the 2 bad cells before I create the 13.3v w/bms.

 

[John Frum]

I am going to try and charge the 2 bad cells before I create the 13.3v w/bms.

Why 13.3 volts?

 

[BobbyMac]

Why 13.3 volts?

I should have said charge to 13.3v. I will not be constantly discharging and charging so the 13.3 us more for storage.

 

[John Frum]

I should have said charge to 13.3v. I will not be constantly discharging and charging so the 13.3 us more for storage.

So you are not going to top balance?