Battery active balancer - extra balancer in på with JK BMS 200A 16s (non-Inverter model)

[silverstone]

I think I have a battery that is quite problematic to charge and holds the other battery back. One cell constantly hits OVP early on... Now I'm trying to add inverter communication to the jk bms, but that won't change the physical issue... One battery will always hold the other one (or several other) back.

At the same time retrofitting another balancer into this battery will require some non-trivial mechanical reworking. Which might actuly require to transplant the cells into another battery box anyways...

At least for the future batteries I'm currently building, I think it's therefore a good idea to include an extra active balancer PERMANENTLY connected.

What are good options (ideally up to 10A real no matter what the voltage difference is, I. E. not only 10A with 1V difference etc)?

- JK-B10A24S not manufactured anymore?
- NEEY???

One must-have feature is the ability to set the start balancing voltage (I use 3.45V based on Andy from off grid garage), not to let it balance all the time.

Thanks for the help

 

[Mahendra Gomanie]

Sounds like cell imbalance or mismatched at the factory etc
Jk -B10A24S is a BMs
Neey.. Is a balancer.
I currently have a neey on my battery bank and it does a great job keeping cells balanced

 

[Mahendra Gomanie]

Check out Off Grid Garage on UTube on the NEEY active balancer, There is also the Newer Smart version of this that is a bit easier to programme.

 

[silverstone]

Sounds like cell imbalance or mismatched at the factory etc
Jk -B10A24S is a BMs
Neey.. Is a balancer.
I currently have a neey on my battery bank and it does a great job keeping cells balanced

Oups

 

[silverstone]

Check out Off Grid Garage on UTube on the NEEY active balancer, There is also the Newer Smart version of this that is a bit easier to programme.

Yeah but I wonder if 4A NEEY is enough. JK BMS I have 2A and is nowhere near enough near the top of the charge process.

And I was kinda in doubt on Aliexpress at least the 10A or 15A seem to be full BMS, not only balancer.

 

[Mahendra Gomanie]

Yeah but I wonder if 4A NEEY is enough. JK BMS I have 2A and is nowhere near enough near the top of the charge process.

And I was kinda in doubt on Aliexpress at least the 10A or 15A seem to be full BMS, not only balancer.

New version of NEEy has 10/15amps balancing

 

[Mahendra Gomanie]

https://a.co/d/7R4Tqg2

Here is the link on amazon

 

[silverstone]

New version of NEEy has 10/15amps balancing

The 10A is crazy expensive though

https://www.aliexpress.com/item/1005006169132890.html?aff_fcid=97b96fdf44b444c989b981efb744531e-1710777460983-02729-_De0zNbT&tt=CPS_NORMAL&aff_fsk=_De0zNbT&aff_platform=shareComponent-detail&sk=_De0zNbT&aff_trace_key=97b96fdf44b444c989b981efb744531e-1710777460983-02729-_De0zNbT&terminal_id=4ccdca4c54d445aeb2729de9ae407349&afSmartRedirect=y

This looks more reasonable from Enerkey

https://www.aliexpress.com/item/1005006011522754.html

 

[silverstone]

https://a.co/d/7R4Tqg2

Here is the link on amazon

Unavailable it says. Thanks though

 

[Mahendra Gomanie]

Yes , the 4 amp does a pretty good job for me and if one don’t work probably get two . It would still be cheaper than the 10amp

 

[silverstone]

Yes , the 4 amp does a pretty good job for me and if one don’t work probably get two . It would still be cheaper than the 10amp

But can you configure the "Start Voltage" for Balancing so it doesn't balance all the time ? Basically only balance if one cell goes above 3.45V?

I kinda got lost with all the different versions and testing from Andy from Offgridgarage, about which does what (I don't even think they changed the product number ????)

 

[Mahendra Gomanie]

you also have to take into consideration that balancing takes time.

I am not sure I mentioned on this forum but I did quite a number of diy lifepo4 packs over the years and noticed that 1amp is a minimum while above two is better for a 100ah battery pack at 48vdc.

I came to this after I would have painstakingly top balanced several packs and still had some imbalanced issues .

Of course you only get this amount of balancing amps from active balancers or BMS with active balancing.

 

[Mahendra Gomanie]

But can you configure the "Start Voltage" for Balancing so it doesn't balance all the time ? Basically only balance if one cell goes above 3.45V?

I kinda got lost with all the different versions and testing from Andy from Offgridgarage, about which does what (I don't even think they changed the product number ????)

Yes I can , but a gain I definitely.

 

[silverstone]

you also have to take into consideration that balancing takes time.

I am not sure I mentioned on this forum but I did quite a number of diy lifepo4 packs over the years and noticed that 1amp is a minimum while above two is better for a 100ah battery pack at 48vdc.

I came to this after I would have painstakingly top balanced several packs and still had some imbalanced issues .

Of course you only get this amount of balancing amps from active balancers or BMS with active balancing.

My 1st battery behaves relatively well with the JK BMS integrating a 2A active balancer Balancer.

However, my 2nd battery behaves really bad, with one cell shooting up at 3.45 ... 3.50 ... 3.55 ... 3.60 within seconds.

That's why in my case implementing the inverter communication is so important.

280Ah each battery cell is not easy to handle with a 2A balancer (without inverter slowing down near the top of the charge curve to give it time to balance properly).

 

[Mahendra Gomanie]

Watch these:

 

[Mahendra Gomanie]

My 1st battery behaves relatively well with the JK BMS integrating a 2A active balancer Balancer.

However, my 2nd battery behaves really bad, with one cell shooting up at 3.45 ... 3.50 ... 3.55 ... 3.60 within seconds.

That's why in my case implementing the inverter communication is so important.

280Ah each battery cell is not easy to handle with a 2A balancer (without inverter slowing down near the top of the charge curve to give it time to balance properly).

Huh well this my assumption for using 1amp minimum for 100ah

I understand seem like those cells are greatly out of balanced or questionable.

Can you charge each cell using and DC power supply? That might help. Painstaking and long .

If not the neey together with the jk is suppose to handle it over a couple of charges.
Since that will bring you to around 6amps combined.

 

[silverstone]

Huh well this my assumption for using 1amp minimum for 100ah

I understand seem like those cells are greatly out of balanced or questionable.

Can you charge each cell using and DC power supply? That might help. Painstaking and long .

If not the neey together with the jk is suppose to handle it over a couple of charges.
Since that will bring you to around 6amps combined.

I had top balanced by slowly ramping up an external power supply / charger during a painstaking 36 hours. Each cell was at 3.60V at that time. In both batteries.

One week later, everything was trashed already and Battery 02 started hitting OVP again .

 

[Mahendra Gomanie]

you might want to charge those batteries separately to full then recombining them .
Large charge amps on initial charge also make it difficult to have a good balance as I mentioned you want to give it some time.
There are some things that you can’t rush.
Been there done that

If it’s any comfort my jk balancer no longer go into balancer mode because the neey would have done the job before it needs to kick in

 

[silverstone]

you might want to charge those batteries separately to full then recombining them .
Large charge amps on initial charge also make it difficult to have a good balance as I mentioned you want to give it some time.
There are some things that you can’t rush.
Been there done that

If it’s any comfort my jk balancer no longer go into balancer mode because the neey would have done the job before it needs to kick in

Yeah with the inverter communication it probably will be better. I just don't like it that it goes out of balance so quickly.

Surely it doesn't help that the cells were grade B, from Docan Power (they delivered one "spare" that was actually leaking electrolyte - thrashed that away). But cannot say for sure there is really a problem. Maybe it's just one cell having like 2% less capacity or something ...

 

[Mahendra Gomanie]

I had top balanced by slowly ramping up an external power supply / charger during a painstaking 36 hours. Each cell was at 3.60V at that time. In both batteries.

One week later, everything was trashed already and Battery 02 started hitting OVP again .

Sounds like problematic cells,
What brand are these ?
But the needy together with the jk is not a bad gamble if you already have it in hand.