Help replacing BMS -

[Politbureau]

I've got a factory 20s11p pack with a woefully (and intentionally) underrated BMS that I am replacing, and could use a hand identifying in what order to swap cables etc. I'm ace at soldering and have a soldering station at home, but this is my first time wiring a BMS.

Old BMS is a JBD ZP series and new is a JBD SP series. I checked the wiring diagrams, and I can plug and play my balance cables to the new controller.

Here is old (L) and new (R)

View attachment JBDSmartBMSSP24S0048S_24S200A.webp

You'll notice the OEM pack design has an DZ47-125A breaker inline with the output port ().

All the tutorials I've read indicate to:

1. solder L-R starting on input side (B-)
2. insert balance cables
3. solder L-R on output side (C-)
4. connect and place the new NTM temperature sensor
5. solder the charge and display cables
6. 'wake up' the BMS by plugging in the OEM charger
7. connect app to bluetooth to confirm pack string, AH, current and temperature protection limits

Is that correct? Any missing steps?

Also - should I convert to ring terminals, or just solder directly? Thanks!

 

[Nix Liou]

I would probably solder directly, since it shouldn't need to be replaced too often. I might solder C- on before connecting the balance wires and temperature, as long as no load is going to be pulled through it. Just a matter of convenience if anything.

Sounds like a good plan.

 

[Politbureau]

I would probably solder directly, since it shouldn't need to be replaced too often. I might solder C- on before connecting the balance wires and temperature, as long as no load is going to be pulled through it. Just a matter of convenience if anything.

Sounds like a good plan.

Many thanks! I'm a tad nervous about this as I don't want to fry anything. And only reason for the wiring the balance wires after B- is the manual indicates that is the correct order? Although it being Engrisch I'm not actually sure what they mean.... Unless you can decode.

 

[Nix Liou]

Many thanks! I'm a tad nervous about this as I don't want to fry anything. And only reason for the wiring the balance wires after B- is the manual indicates that is the correct order? Although it being Engrisch I'm not actually sure what they mean.... Unless you can decode.

View attachment 387031

Yeah, you should follow what the instructions say. It's usually due to how the bms draws power from the battery, or how it does the "smart" part and figures out how many cells they are.