Drowning. Need help JK BMS B5A25S60P (have 2)

Sorry in advance for all the ignorance from me on this. I’m caught in a trap that I had no intention of entering. Assumed I could swap out LA battery bank for Lifepo4 from China. Battery for battery 48v system. Have lived Offgrid for 6 years. Need help.

Anything really (preferably a wiring diagram in English). I’ve watched several videos from Andy (offfrid garage) by necessity and have learned very little as nothing seems to apply to my situation. Thanks in advance!! Here’s what I have:

I purchased 32 - 280ah 3.2 v CATL batteries. Doing two strings in parallel of 16 batteries in series. Found out I need a BMS for each string of 16. Purchase two JK B5A25SA60P and two 16s equalizers (pic attached). The BMS has a shunt (pic attached). To attach my battery cables I purchased lugs to go 4/0 cable to 1/4” terminals (pic attached).

For my current system I have 2 Magnum Energy MS4448PAE inverters and two midnite solar classic 150 charge controllers.

Where to begin?!?! - an English manual would be awesome. JK has not provided. Any links they’ve shared and all I see or can find is a Chinese manual.

I live in Saskatoon Sk Canada. Did not intend to trail blaze this one on my own. Happy to pay someone who can draw me an install diagram that applies to my hardware. My magnum energy panel has some built in breakers for the current battery bank so I want to avoid redundancy.

Does anyone have any experience with these inverters/charge controller and this specific BMS doing a lifepo4 upgrade?

Again I apologize for the ignorance and very much appreciate any help!!! This my first forum post ever.

Desperate and grateful,

Luke

Some sort of manual in English is here.
Or see here.
-

The JK-BMS has built in cell balancing of 2A. I would suggest using the BMS balancer and not the other product. In either case, it is not advisable to use both at the same time.

BentleyJ said:

The JK-BMS has built in cell balancing of 2A. I would suggest using the BMS balancer and not the other product. In either case, it is not advisable to use both at the same time.

Click to expand...

That is great advice. I thought these were capacitors when I purchased them, the bot or whoever monitors their inbox in Alibaba suggested I buy capacitors so I assumed these were them. They look the same from the picture.

Maybe I don’t need a capacitor?

Thank you so much for the helpful advice this does certainly simplify my setup which I love!! ???

I’m tempted to bypass a BMS and let my charge controllers do the equalizing. If that’s even possible. They did them for my LA banks.

Don B. Cilly said:

Some sort of manual in English is here.
Or see here.
-

Click to expand...

Wow this is huge. I’ve downloaded a copy and will now spend today reading it. You’ve saved me hours of time looking and banging my head against the wall haha. God bless you!

LukeL said:

I’m tempted to bypass a BMS and let my charge controllers do the equalizing. If that’s even possible. They did them for my LA banks.

Click to expand...

Nope absolutely not, use the BMS.

Quattrohead said:

Nope absolutely not, use the BMS.

Click to expand...

Thank you . I suspected this was the case but I’m glad you guys have removed all doubt.

LukeL said:

Sorry in advance for all the ignorance from me on this. I’m caught in a trap that I had no intention of entering. Assumed I could swap out LA battery bank for Lifepo4 from China. Battery for battery 48v system. Have lived Offgrid for 6 years. Need help.

Anything really (preferably a wiring diagram in English). I’ve watched several videos from Andy (offfrid garage) by necessity and have learned very little as nothing seems to apply to my situation. Thanks in advance!! Here’s what I have:

I purchased 32 - 280ah 3.2 v CATL batteries. Doing two strings in parallel of 16 batteries in series. Found out I need a BMS for each string of 16. Purchase two JK B5A25SA60P and two 16s equalizers (pic attached). The BMS has a shunt (pic attached). To attach my battery cables I purchased lugs to go 4/0 cable to 1/4” terminals (pic attached).

For my current system I have 2 Magnum Energy MS4448PAE inverters and two midnite solar classic 150 charge controllers.

Where to begin?!?! - an English manual would be awesome. JK has not provided. Any links they’ve shared and all I see or can find is a Chinese manual.

I live in Saskatoon Sk Canada. Did not intend to trail blaze this one on my own. Happy to pay someone who can draw me an install diagram that applies to my hardware. My magnum energy panel has some built in breakers for the current battery bank so I want to avoid redundancy.

Does anyone have any experience with these inverters/charge controller and this specific BMS doing a lifepo4 upgrade?

Again I apologize for the ignorance and very much appreciate any help!!! This my first forum post ever.

Desperate and grateful,

Luke

Click to expand...

Ok so thanks to you guys I have a diagram for my BMS and an English manual and now know I wasted money on the capacitor (active balancer things I bought) - excellent. ???

I’ve translated the diagram to include English in chicken scratch writing (my bad). See attached for anyone else’s reference.

I watched another off grid garage video but his BMS is simpler and leaves many unaddressed concerns. (2A vs 5A, mine has a shunt, his must be built in among other things). Actually he spent about 30 seconds on a 32 min video showing the actual BMS hardware install. Still learned a few helpful things on the programming. Here’s a link for reference:


Looks like on my BMS there will be many unused ports - so far I can see I won’t be using P3 for sure (I’m only doing 16 batteries in series), P5 too (GPS) and possibly P6 (LED I believe won’t use im using the app) and much of P4 that applies to the “load”. See attached pic of BMS and reference diagram.

*Assumption: I’m hoping that since I don't need a “load” like a light bulb but will be hooking up directly to my inverter/controller or my home power that I can bipass all of these “contactors” that are going to the load. Rather my system will be continually charging/discharging from my home’s power consumption. These contactors will also be seriously resting the power flow from 4/0 cable down to 18 g of the BMS. So if they’re not necessary I don’t want to use them.

Yes I’ll be charging up and balancing the bank with a bench power supply before I actually hook up to the inverter (house).

So I’ve tried to take their diagram and transpose it to my needs. It looks like many of the BMS terminals will not be used for me - I hope. Unless someone can set me straight here. See attached pic.

My questions are specifically (other than general mistakes I may be making in findings above).


1) on the positive side from house power, whether I need the “charging contactor” or if I can go from my inverter directly to the + terminal on my batt bank with 4/0 cable so as to not reduce any current flow (I have a good panel lug to make this happen). From what I understand these contactors are super small and for low voltage. My power input from inverters are big time (4/0 cable is what we used).

2) on the negative side from the house power, from my inverter to the shunt will be 4/0 cable; from the shunt to the negative terminal on the battery bank - can this simply be 18 g or should I attempt to make it up in 4/0 using some lugs? To ensure no current restrictions.

3) *referencing above assumption about the load in the Chinese diagram: am I ok in my situation to bypass those contactors on the “load” segment of their diagram since I won’t be using one for my home power application. No clue where they would go in relationship to my home power + - terminals from my inverter panel if I do need them. Or if they’re needed - where to buy etc. I also asked Hankzor store. Waiting for reply.

Thank you thank you in advance.

I have the 2A version of this BMS and am about to install it (finally) and have found little documentation. I did find two diagrams that together tell the wiring story though.

Also posted this in the other thread for this BMS

I found this diagram which is in English.




The diagram below is from a Chinese manual I found for the JK-B2A25S-RP which has English labelled pin outs that actually match what the cables are labeled with. This is what I was guessing from the diagram posted just prior, but nice to have confirmation.

I am going to install likely today to replace my failed BMS - Balancing and power out to the display is not working. Using only one battery relay only as I have an integrated inverter/charge controller. If I had a separate charge controller I would use another relay for the charge function. I may add the charge relay in the future as I will occasionally charge the battery with a power supply as my setup is a whole house battery backup vs solar and I can run the external charger through the charge relay which will be more convenient. Using the Discharge relay outputs only, and I will wire K+/C to the load side of the Discharge relay. I am Wiring all the grounds to B-, not using the pre-Charge feature at this time so not wiring ACC+. No heaters so not using the H or Heater connections.

LukeL said:

Ok so thanks to you guys I have a diagram for my BMS and an English manual and now know I wasted money on the capacitor (active balancer things I bought) - excellent. ???

I’ve translated the diagram to include English in chicken scratch writing (my bad). See attached for anyone else’s reference.

I watched another off grid garage video but his BMS is simpler and leaves many unaddressed concerns. (2A vs 5A, mine has a shunt, his must be built in among other things). Actually he spent about 30 seconds on a 32 min video showing the actual BMS hardware install. Still learned a few helpful things on the programming. Here’s a link for reference:

Looks like on my BMS there will be many unused ports - so far I can see I won’t be using P3 for sure (I’m only doing 16 batteries in series), P5 too (GPS) and possibly P6 (LED I believe won’t use im using the app) and much of P4 that applies to the “load”. See attached pic of BMS and reference diagram.

*Assumption: I’m hoping that since I don't need a “load” like a light bulb but will be hooking up directly to my inverter/controller or my home power that I can bipass all of these “contactors” that are going to the load. Rather my system will be continually charging/discharging from my home’s power consumption. These contactors will also be seriously resting the power flow from 4/0 cable down to 18 g of the BMS. So if they’re not necessary I don’t want to use them.

Yes I’ll be charging up and balancing the bank with a bench power supply before I actually hook up to the inverter (house).

So I’ve tried to take their diagram and transpose it to my needs. It looks like many of the BMS terminals will not be used for me - I hope. Unless someone can set me straight here. See attached pic.

My questions are specifically (other than general mistakes I may be making in findings above).


1) on the positive side from house power, whether I need the “charging contactor” or if I can go from my inverter directly to the + terminal on my batt bank with 4/0 cable so as to not reduce any current flow (I have a good panel lug to make this happen). From what I understand these contactors are super small and for low voltage. My power input from inverters are big time (4/0 cable is what we used).

2) on the negative side from the house power, from my inverter to the shunt will be 4/0 cable; from the shunt to the negative terminal on the battery bank - can this simply be 18 g or should I attempt to make it up in 4/0 using some lugs? To ensure no current restrictions.

3) *referencing above assumption about the load in the Chinese diagram: am I ok in my situation to bypass those contactors on the “load” segment of their diagram since I won’t be using one for my home power application. No clue where they would go in relationship to my home power + - terminals from my inverter panel if I do need them. Or if they’re needed - where to buy etc. I also asked Hankzor store. Waiting for reply.

Thank you thank you in advance.

Click to expand...

Hi Luke

Your BMS has an active cell balancer so you only need to use that and not the separate active balancer. Your BMS is a bit different than the one Andy is using, which uses an internal bank of electronic switches to turn the power on and off. Your BMS needs external relays to work. You will need at least one relay for each of your battery banks/BMS units so the BMS can do it's job and shut down the battery if there is a problem.

The Load in the diagrams is the inverter which is true for most people
You Need a separate BMS for each of your battery packs
They would be wired in parallel so you have 48-54 volts (LifePo4 battery) going to the inverter, each battery providing half the current.

This BMS needs high amperage DC relays to switch the battery on and off, if you don't have at least one of those, this will not work.
This is the one I am using:





As wiring this BMS doesn't seem to be documented that I can find, this is my diagram, which is for one battery but trying to give an example to see how the wiring is for my plans. You will have to decide for yourself what you want to do. Yours would have the BMS managing each battery, and then both positives and negatives connecting together after the shunts. Each Pack will have a discharge relay, shunt and a BMS. And ideally a DC disconnector and DC fuse sized for the load for each battery. You could put the two POSITIVE lugs together on the + Input terminal on the Inverter, and the same for both NEGATIVE battery lugs on the - terminal of the inverter DC inputs.

Below is the updated wiring diagram. You need to connect the ACC+ to the Pre-Charge + wires in order to power the 12V releays.

Burke said:

Below is the updated wiring diagram. You need to connect the ACC+ to the Pre-Charge + wires in order to power the 12V releays.

Click to expand...

Hi Burke,

Thanks for sharing your wiring diagram. Are you also connecting the BMS communication wires to your Inverter as well? If so, are you able to share which inverter are you using? Thanks