JBD BMS Toast?

[europa1]

I have a JBD 100A BMS running a 270Ah 12v 4 cell Lifepo.
Suddenly, using the Overkill app, the battery started to discharge about 4amps without ANY power attached. So I disconnected battery from system and took the following reading from the Overkill App.
1. 3.105
2. 1.983
3. 0.046
4. 2.270

Please note cell 3 voltage

I then remove the BMS and tested each individual cell with a multimeter, results as follows:

1. 3.098
2. 3.053
3. 3.085
4. 3.125

As you can see the, the voltage difference, especially Cell 3, is amazing, I,m assuming unless someone can advise differently that the BMS is blown and requires replacing. I am already running a JBD on another 270Ah battery, which was wired in parallel to the above apparently faulty battery. Do I have to purchase a replacement JBD or can I use another BMS from a different maker
Many thanks

 

[Rogerb]

Check the sense leads to the JBD to verify the app voltage readings.
If they are the same as the app, the connections at the battery are suspect.
If they are the same as the individual voltages, the BMS may have failed.

Let us know what you find.

 

[LakeHouse]

Do I have to purchase a replacement JBD or can I use another BMS from a different maker

No need to use a JBD for the replacement.

 

[Juptron]

No need to use a JBD for the replacement.

What is the best replacement for a JBD Bms?

 

[Daddy Tanuki]

sorry but this sounds like bad connections more than anything... did you check your buss bars and your BMS connections? honestly thats what it looks like on paper.

Edit: my answer to the OP.

to @Juptron any BMS will work if setup properly. some fo them better some of them worse, but they all basically work.

 

[LakeHouse]

What is the best replacement for a JBD Bms?

I’m partial to the JK BMS, but it’s also the only BMS I have experience with.
Lots of people here have lots of different opinions.

 

[meetyg]

In my opinion, JBDs are work horses, but lack active balancing. You can really tweak the parameters with JBD.

JK are also good, but there have been some reliability issues, especially with heated versions.
I find JKs easier to configure, as there are less parameters than JBD (but still a whole lot, enough for a good DIY build).

There is also a small bug with JKs: If discharge MOSFET is off (either because of LVP or manually), if a charge is applied, it doesn't open the discharge MOSFET like it should, untill charge voltage is high enough (don't recall how much higher). In effect, this means that charging is also disabled. JBDs don't have such a bug.