Fan on daly is running when ESP is connected

[DetlefR]

Hello,

I have buld a new battery with a 500A daly BMS.
For monitoring, I use, like on the old battery, daly2mqtt. The ESP use the 3.3V power from BMS and has only RX/TX connected. The software is working well (version 2.14).
Strangely, the fan on BMS is running if I plug in the ESP and going off if I unplug it.

Any idea.
Thanks Detlef.

[softwarecrash]

this is a symptom when the bms cannot deliver enugh power to the esp, you need to power the esp external

[DetlefR]

That was it. What a pity.

Thanks for your fast answer.