The massive capacity loss of a out of balance pack.

[James340]

I have active Balance on all my packs.Normally I never see one light up/balance but this balancer has been on often recently and I was concerned but didn't check the battery.I was going to ride this bike so put the battery on to charge.It stopped at 50.7 volt.I put another active balancer on the pack and it has been lit up for 14 hours .Seems like the balancer actually unbalanced the pack.I checked the other 5 packs are.1 volt or less.Balancer is supposed to balance at .2 volt difference.

 

[James340]

I recently had a 13s3p pack stop charging at 51v.I ran it down to LVC which happened with the pack voltage of 46 because of the low cells.I recharged it with a Amp/Watt meter attached.Pack is 14ah but only accepted 5.6ah.Series #1 to 13 voltage varies one tenth of a volt.I have active balancer that look similar to a BMS but is for balance only.Those don't balance until two tenths of a volt difference I am looking for a better Active Balancer.I don't want another app on my phone for a smart balancer but I don't want to be dumb either.Any body have experience with a active balancer that works?

 

[lnanek]

Are you sure it was actually done charging? A BMS with resistors to bleed down any parallel groups that reach max voltage often stops charging temporarily until the highest group is low enough to start bulk charging the whole thing again.

 

[James340]

Are you sure it was actually done charging? A BMS with resistors to bleed down any parallel groups that reach max voltage often stops charging temporarily until the highest group is low enough to start bulk charging the whole thing again.

I left it changing over night.I don't want to leave it on the charger for days hoping the BMS balance's it.I am really disappointed the active balancer does not start until 0.2 volt difference between cells.I didn't realize that when I bought them.

 

[James340]

This is the balancer I have

 

[docw009]

Charger stops at 51V? That's 3.92V/cell for a 13S, not even 80% charged. Maybe your active balancer is interfering with the BMS.

 

[James340]

Charger stops at 51V? That's 3.92V/cell for a 13S, not even 80% charged. Maybe your active balancer is interfering with the BMS.

The balancer is connected to the battery not BMS.The first 3 series are 3.7 v the next 2 series 3.8 v ect by the 11 series it's 4.2 v.

 

[James340]

I have a 18650 charger.Can I do charge the first series? Will chargeing the first series charge 2,3 ect? Bringing the lowest series up to full charge? Thank you everyone for the help.

 

[lnanek]

Wow, that thing has really bad reviews:

https://a.co/d/hzVdlUh

Yes, if you have a 3s charger you can just unhook everything then wire that up to the any three p-group groups at once, 1s charger, unhook everything then just charge 1 p-group, etc.. Electricity needs a circuit to flow, so if the unused p-group groups on either side of the one you are charging aren't hooked up to any full circuit anywhere, nothing is going to happen with them. Just being part of a series that isn't hooked up to anything at either end isn't enough to activate them.

 

[wturber]

I recently had a 13s3p pack stop charging at 51v.I ran it down to LVC which happened with the pack voltage of 46 because of the low cells.I recharged it with a Amp/Watt meter attached.Pack is 14ah but only accepted 5.6ah.Series #1 to 13 voltage varies one tenth of a volt.I have active balancer that look similar to a BMS but is for balance only.Those don't balance until two tenths of a volt difference I am looking for a better Active Balancer.I don't want another app on my phone for a smart balancer but I don't want to be dumb either.Any body have experience with a active balancer that works?

A few things. First, a 13s3p back is probably not 14 ah. That would suggest that each cell is 4666 mah capacity. Typical cell capacities range from 2600 mah to 3300 mah. I think the highest capacity 18650 cells are around 3600 mah.

If you are charging the full battery normally with a normal charger on the charge port of your battery and the battery stops charging at 51v, then it is likely that one or more banks have one or more defective cells. I think you need to track down the defective cells.

Whether or not you should start trying to charge cells with an 18650 charger has everything to do with how easy it is to separated cells.

 

[James340]

Wow, that thing has really bad reviews:

https://a.co/d/hzVdlUh

Yes, if you have a 3s charger you can just unhook everything then wire that up to the any three p-group groups at once, 1s charger, unhook everything then just charge 1 p-group, etc.. Electricity needs a circuit to flow, so if the unused p-group groups on either side of the one you are charging aren't hooked up to any full circuit anywhere, nothing is going to happen with them. Just being part of a series that isn't hooked up to anything at either end isn't enough to activate them.

This is a assembled pack so no way of separate chargeing unless I cut it apart.So I guess it's going to spend some time with the charger and see if the BMS balances it.Thanks for the help

 

[James340]

A few things. First, a 13s3p back is probably not 14 ah. That would suggest that each cell is 4666 mah capacity. Typical cell capacities range from 2600 mah to 3300 mah. I think the highest capacity 18650 cells are around 3600 mah.

If you are charging the full battery normally with a normal charger on the charge port of your battery and the battery stops charging at 51v, then it is likely that one or more banks have one or more defective cells. I think you need to track down the defective cells.

Whether or not you should start trying to charge cells with an 18650 charger has everything to do with how easy it is to separated cells.

It's 21700 cell but battery builders tend to exaggerate

 

[wturber]

It's 21700 cell but battery builders tend to exaggerate

So you were going to rig up some wires to use an 18650 charger on your 21700 cells?

 

[James340]

So you were going to rig up some wires to use an 18650 charger on your 21700 cells?

The voltage is the same only capacity is different

 

[docw009]

The balancer is connected to the battery not BMS.The first 3 series are 3.7 v the next 2 series 3.8 v ect by the 11 series it's 4.2 v.

If it's connected to the cells, it's connected to the BMS.

 

[Hillhater]

You probably have a bad (open circuit or dry contact) cell somewhere in there preventing full charge / discharge of the pack.
Its going to be hard to identify which one.

 

[James340]

Wow, that thing has really bad reviews:

https://a.co/d/hzVdlUh

Yes, if you have a 3s charger you can just unhook everything then wire that up to the any three p-group groups at once, 1s charger, unhook everything then just charge 1 p-group, etc.. Electricity needs a circuit to flow, so if the unused p-group groups on either side of the one you are charging aren't hooked up to any full circuit anywhere, nothing is going to happen with them. Just being part of a series that isn't hooked up to anything at either end isn't enough to activate them.

I don't understand what you are telling me.I was wondering if this idea will work.Use the wires to the balance board and the buck converter to charge/discharge a series?I can adjust the converter to what ever voltage the series is to charge.Using the light & converter to discharge a series.Is this possible? This idea is to do 1 series at a time.Discharging highest seems safest.The watt meter makes it easier to monitor as it is happening

 

[James340]

Thank you for the time.I really appreciate it