JBD/LLT SmartBMS questions and info

[fessyfoo]

reference

@AlexB

Hi all, finished building my 18s6p P45B pack and did my BMS wiring yesterday. I am using a JBD SP22S003 BMS and everything seemingly went fine except for my final readout. The diagram shows leads BC16-17-18-19-20 as getting combined, however on my connector there is no lead for where BC20 would be - it skips and has the last 2 leads. I combined the 4 wires 16-19 and finished it off per the diagram, however I am getting an odd readout on the Xiaoxang app. Not sure if I should add a lead where there is one missing, and add it to the other combined leads? Even though the BMS model number is SP22, it’s listed as a 21S BMS (and the missing wire would confirm that also).

Any thoughts? Thanks in advance and happy holidays all.

@Skyart

What i normally do is remove the black plastic cover on the back of the BMS and solder those pins together at that location.

@AlexB

I just ran all 4 leads to the 16th P group since it wasn’t a long run. Do you have any idea what might be up with the funky reading? I haven’t used this BMS in particular before, only the 10-17S one before.

@Skyart

The weird reading comes from the missing lead messing up the way the BMS reads voltage. You could just solder that one to the reatbof the group, but i recomend soldering all of them together at the back of the BMS and removing all but one of those leads that go to your group 16.

After that you should be able to plug everything in and it will read lile it should. If it doesnt you will need to go into the settings menu and charge the BMS from 21s to 18s

@AlexB

Thanks, ended up jumping them on the back of the BMS and all is reading well now Now need to ride it!