Active balancing options for a pack that already has a BMS.

[rjg13]

Hi all,

I have an Eco-Worthy 48V 50ah LFP pack. It has a JBD 16s BMS. I cannot seem to find any information on this BMS, but I want to change the balance voltage. This has caused me to look for an active balancer where I can adjust the balance voltage. Currently, the balance voltage on the JBD is set to around 3.5V. I want to lower that, to 3.35-3.375. I have two options in mind so far.

1. Change the BMS to a JK BMS so I can adjust the balance voltage.
2. Add an active balancer to the battery pack, in addition to the current BMS.

In your opinion, what would be the best path forward?

Also, what are my options for manufacturers/models? I have seen JK, 100balance, and NEEY. Which manufacturer should I go with?

Thank you

 

[Rednecktek]

Either way will require futzing with the cells, and an active balancer will work along side the BMS and be cheaper and easier to set up.

 

[hwy17]

You have an ecoworthy 50Ah? Is this the one we're talking about using for a UPS? (we don't have to rehash all that here, just checking).

I'd be very curious if you open the lid to get some pics up on the forum. I haven't seen the inside of one yet or whether BMS retrofit is possible. Are they prismatic cells or pouches? I don't know yet. Maybe others do.

 

[Ampster]

In your opinion, what would be the best path forward?

If you can disable the balancing on the JBD BMS then #2 is the least expensive. I had good luck with the 2 Amp JK active balancer. I also heard good things about the Neely.

 

[rjg13]

You have an ecoworthy 50Ah? Is this the one we're talking about using for a UPS? (we don't have to rehash all that here, just checking).

I'd be very curious if you open the lid to get some pics up on the forum. I haven't seen the inside of one yet or whether BMS retrofit is possible. Are they prismatic cells or pouches? I don't know yet. Maybe others do.

Yes. I can post pics. Prismatic cells, looks like a standard pack setup, has two NTC thermistors as well, from the looks of it.

 

[42OhmsPA]

Hi all,

I have an Eco-Worthy 48V 50ah LFP pack. It has a JBD 16s BMS. I cannot seem to find any information on this BMS, but I want to change the balance voltage. This has caused me to look for an active balancer where I can adjust the balance voltage. Currently, the balance voltage on the JBD is set to around 3.5V. I want to lower that, to 3.35-3.375. I have two options in mind so far.

1. Change the BMS to a JK BMS so I can adjust the balance voltage.
2. Add an active balancer to the battery pack, in addition to the current BMS.

In your opinion, what would be the best path forward?

Also, what are my options for manufacturers/models? I have seen JK, 100balance, and NEEY. Which manufacturer should I go with?

Thank you

Does the JBD have bluetooth? Have you tried the xiaoxang or overkill solar app?
Why do you want to try to balance in flat part of the curve? It seems like a waste; from what I understand you want to balance ~4.2V.

3 JBDs here with balancing set @4.2V
(Pack #2 wasn't top balanced)

 

[Q-Dog]

None of the above. I would let the pack absorb longer, or just charge the pack to a higher voltage.

 

[rjg13]

You have an ecoworthy 50Ah? Is this the one we're talking about using for a UPS? (we don't have to rehash all that here, just checking).

I'd be very curious if you open the lid to get some pics up on the forum. I haven't seen the inside of one yet or whether BMS retrofit is possible. Are they prismatic cells or pouches? I don't know yet. Maybe others do.

Eco-Worth 48V 50ah internal pictures

So it was mentioned to me that there have been no pictures of the Eco-Worthy 48V 50ah packs. I've been messing with mine and decided to share some internal pictures. There's a phenolic resin sheet to cover the top of the battery. The handle has to be removed if you want to access the BMS. The...

diysolarforum.com

Does the JBD have bluetooth? Have you tried the xiaoxang or overkill solar app?
Why do you want to try to balance in flat part of the curve? It seems like a waste; from what I understand you want to balance ~4.2V.

3 JBDs here with balancing set @4.2V
(Pack #2 wasn't top balanced)

I cannot charge it correctly in the current application, so I need to balance at those voltages.

None of the above. I would let the pack absorb longer, or just charge the pack to a higher voltage.

Not possible, hence why I asked my question. Thanks for the input though.

 

[42OhmsPA]

I cannot charge it correctly in the current application, so I need to balance at those voltages

What voltage are you charging at?
You won't balance in the flat part of the curve, might even make it worse, need to balance in the knee.

 

[rjg13]

What voltage are you charging at?
You won't balance in the flat part of the curve, might even make it worse, need to balance in the knee.

This has been discussed at length in my other post.

 

[42OhmsPA]

This has been discussed at length in my other post.

Just skimmed through it, hope you get things working.

I've read good things about JK and would go that route myself if I didn't already have 3 JBDs in 16s that work great besides passive balancing.

 

[rjg13]

Just skimmed through it, hope you get things working.

I've read good things about JK and would go that route myself if I didn't already have 3 JBDs in 16s that work great besides passive balancing.

I ended up picking up a NEEY 4a active balancer on Aliexpress. I'm planning on just adding it into the pack as is. Seeing as the JBD seems to start balancing at 3.5, and I'm trying to balance below that, it should work.