JK B2a8s30p

[Scotchalan]

Has anyone got any info on the 300a jk bms model - b2a8s30p

Also I’m not sure what the C- is for ??

 

[NVS]

It looks like the c- is for charging connection. So you connect the negative lead on your charger here. Whether that be via converter or from solar.

So this BMS splits the charging and load negative wires.

 

[littleharbor2]

It looks like the c- is for charging connection. So you connect the negative lead on your charger here. Whether that be via converter or from solar.

So this BMS splits the charging and load negative wires.

So, when an AIO charges direct through the Battery cables would this particular BMS not work?

 

[littleharbor2]

Is this model number a typo? All I see when googling it is a 20P model, not 30P?

 

[NVS]

So, when an AIO charges direct through the Battery cables would this particular BMS not work?

That's correct you need to get a different BMS. You need a common port BMS not a separate port BMS.

 

[Hans Kroeger]

I bought about 30 units b2a8s20p and had no problems up till now (except for the password problem, which was resolved by an update of the app). Now I got my first b2a8s30p and I will try to figure out what all the new features are, like pre discharge etc......
I could not find any manual up till now. The only drawing I found does not explain anything to me. May be someone else is smarter than me and can explain this drawing below. I will keep you posted on this BMS once I have it running......
Cheers Hans

 

[Bob B]

I bought about 30 units b2a8s20p and had no problems up till now (except for the password problem, which was resolved by an update of the app). Now I got my first b2a8s30p and I will try to figure out what all the new features are, like pre discharge etc......
I could not find any manual up till now. The only drawing I found does not explain anything to me. May be someone else is smarter than me and can explain this drawing below. I will keep you posted on this BMS once I have it running......
Cheers Hans

I can't help with the rest of your questions, but that diagram appears to show how to wire 2 batteries in parallel using this BMS.

 

[Hans Kroeger]

That's correct you need to get a different BMS. You need a common port BMS not a separate port BMS.

Hi there,
I just connected my new b2a8s30p the same way as the b2a8s20p. Did not use the C terminal. I can confirm that it is a common port BMS.
Still don't know what the C terminal can be used for.
Cheers Hans

 

[Hans Kroeger]

I found a note in a German forum, which states that the pre discharge function is a precharge function for the high capacitance input of an Inverter. Could not figure out how it works. Will keep you posted.....

 

[Hans Kroeger]

The B2A25S-RP is based on relays, rather than MOS-FETs. IT offers a relay driver output for a pre-charge relay, and it's function is reflected in the status page of the App. May be that Jikong did not remove the concerned parameter from the B2A8S30P software?

 

[Hans Kroeger]

Has anyone got any info on the 300a jk bms model - b2a8s30p

Also I’m not sure what the C- is for ??

I own two units B2A8S30P. Both show the same problem. If you trigger an UVP switch off and the cell voltages recover back to the UVPR threshhold, the discharge MOSFETs get stuck in the OFF Position and send a warning message........
All of may B2A8S20P show not such a fault. They simply turn the discharge MOSFET back on and return to normal operations.
Any comments?

 

[meetyg]

I own two units B2A8S30P. Both show the same problem. If you trigger an UVP switch off and the cell voltages recover back to the UVPR threshhold, the discharge MOSFETs get stuck in the OFF Position and send a warning message........
All of may B2A8S20P show not such a fault. They simply turn the discharge MOSFET back on and return to normal operations.
Any comments?

I have this problem with the 20p model:

JK BMS cell UVP ‐ Prevents charging via AIO inverter

A short intro: I have a 24v DIY Lifepo4 pack, 8x105Ah EVE cells. While I got these cells from a reputable supplier (grade A), it seems one cell is a bit faulty. If I recall correctly, there was one cell in this order that made a slushing sound when I shake it, it might be this one. There was no...

diysolarforum.com

I actually have two, one of them seems to be older FW, but both have this problem.

On UVP, the discharge MOSFET turns off, and doesn't turn on while charging, untill voltage rises high enough to overcome the voltage drop on the MOSFET ( something like 0.6v, according to Andy's video).
This is problematic for me, because I have two 24v packs in parallel (each with a JK BMS) and when one goes UVP, the other will continue to charge and then when voltage is high enough, the other starts charging, but with a fair delta of voltage between them and lots of current flowing from o e to the other.
On JBD BMSs, the discharge MOSFET turns on almost immediately after a charge voltage is applied.

 

[frekvai]

I Just recived my B2A8S30P

The C- is not a charge port as far as I know, It should be an output for a heater, It should turn on in case the battery temperature drops below a certain threshold, I Will connect the Bms to my battery and see how It works.