JK BMS BLE Connection Issues

[webbbn]

I have a pair of B2A20S20P JK BMS that work great, but they've gotten into a mode where, if I disconnect the bluetooth connection I can't reconnect without restarting the BMS. It started on one of them a while back, and now the other one is doing it. The appear to be connected to something (the LED is solid), but I don't know what. I've turned off every bluetooth device I can think of to try to figure out what it is, with no luck. We're also far enough from our neighbors that I don't think it could reach that far.

Has anyone else had this issue and figured it out? Anyone know of a way to do a bluetooth scan to try to figure out what it's connecting to? I tried using wireshark with an SDR, and was able to see bluetooth traffic, but didn't seem the JK MAC addresses in the logs.

One of them also always just powers on when I plug it in. I have the LCD display, and the second one doesn't power on until I push the button on the LCD. Is there a setting for auto-power-on that I am not seeing?

 

[webbbn]

I'm not sure I fully understand it, but it appears to be fairly common. At least common enough that batmon-ha has a configuration option specifically to work around it (bt_power_cycle). This option power-cycles the bluetooth adapter before trying to connect, so there is no other device required. Somehow it connects to the device that you're trying to connect to it with, without that device initiating the connection.

I ran into a similar issue with a Victron shunt that had somehow gotten paired with the device that I was trying to connect to it with. I used bluetoothctl to unpair it, and now it's working well.