Can't get JBD BMS to work

[Aphers]

I've just built a 4S pack with a 200A JBD.
This is my second build, and my third JBD (I previously upgraded from 120A to 200A on my first project).

I noticed that the new battery is offline. I cannot get my original Xiaoxiang app to connect to the new battery. I've downloaded a different app (Xiaoxiang electric) which does connect and let's me get in, but I cannot change any settings.

Any suggestions?

If I can't get this working I'll have to just swap out the new BMS for my old 120A which I have kept as a spare. Which would be a shame and mean new crimped connections etc required.

 

[sunshine_eggo]

Uninstall the current BMS software.
Check bluetooth devices and forget the existing BMS.
Install the overkillsolar app

 

[740GLE]

The new BMS 200a, does the Bluetooth dongle light up blue?

I also second the overkill App, works great for iOS, haven’t tried it on Android.

 

[sunshine_eggo]

The new BMS 200a, does the Bluetooth dongle light up blue?

I also second the overkill App, works great for iOS, haven’t tried it on Android.

I've only used Android, and concur it works great.

 

[Brett V]

The Bluetooth dongle lights blue when you connect to it.

 

[MisterSandals]

Any suggestions?

If I can't get this working

Why does your pic show your battery voltage to be 0.0V?

 

[42OhmsPA]

The overkill app doesn't work with all models.
I can confirm it doesn't work with the models attached.

Make sure location is enabled and access granted (on Android) before trying to connect.

 

[740GLE]

I use the overkill app with my JBD 200a 4s bought April 2022, which I believe is the same BMS of the OP.

 

[MisterSandals]

I use the overkill app with my JBD 200a 4s bought April 2022, which I believe is the same BMS of the OP.

Where do you see what BMS the OP has?

I am wondering if OP has an 8-21S BMS (as pictured by 42OhmsPA) and the balance wires are not properly connected.

 

[Aphers]

Why does your pic show your battery voltage to be 0.0V?

It's showing zero for everything- capacity, charge rate, etc. Simply was not recognising the BMS.
Since then, it has sprung in to life, no idea why.
The Overkill app will find my old BMS, but not the new one. The Xiaoxiang electric app will now find the new one, but it doesn't give me individual cell voltage information so it's not a long term solution.

 

[Aphers]

This is the new BMS

 

[Aphers]

The new BMS 200a, does the Bluetooth dongle light up blue?

I also second the overkill App, works great for iOS, haven’t tried it on Android.

It doesn't have a light, it's just a little white block of plastic.
The blue light on the main BMS comes on.

 

[MisterSandals]

This is the new BMS

I will assume you had the 5 balance wires connected correctly. Did you have the B- connected too?

 

[Aphers]

I will assume you had the 5 balance wires connected correctly. Did you have the B- connected too?

Yes, those wires are hooked up, and the B- and C-.
I bench tested the battery with a tiny load and it came to life. But at that stage I hadn't tried connecting to the BMS. After installing it, I couldn't get the app to work with the BMS, but I could tell from looking at the other BMS that it wasn't contributing anything when I applied a large load.

 

[740GLE]

Where do you see what BMS the OP has?

I am wondering if OP has an 8-21S BMS (as pictured by 42OhmsPA) and the balance wires are not properly connected.

He stated he has a 4s JBD 200a, there are only two versions both nearly identical that I’m aware of.

 

[740GLE]

Yes, those wires are hooked up, and the B- and C-.
I bench tested the battery with a tiny load and it came to life. But at that stage I hadn't tried connecting to the BMS. After installing it, I couldn't get the app to work with the BMS, but I could tell from looking at the other BMS that it wasn't contributing anything when I applied a large load.

Do you have multiple BMS functional? I’ve always had an issue with swapping apps to read my one BMS.

I’m not sure it’s similar to having multiple BMS and trying to read each one via one app. Try shutting off BT on your device, turning it back on then trying the app again.

 

[Aphers]

It seems to be working now. I have no idea what I did to get it to work.
The only thing that comes to mind is that the cells were up at 3.6v from doing the top balance a day or two ago. Is it possible that this triggered some kind of shutdown?? But surely the BMS would still have let me in. And in any case, I was able to bench test the complete battery with a small load and it gave power- I just didn't try connecting to the BMS at that point.