Dear community, I have a question about ESD protection of battery powered devices. The battery is non-replaceable and non-rechargeable and will be connected to the boost DC/DC converter. The device is a water flow sensor, which will consists of few PCBs mounted inside IP68 aluminium chassis with a cut-out in the top cover for a glass, to see the display through it. Whole chassis will be painted outside. The device will have antenna connector on the one side of the chassis and another industrial connector for communication interfaces e.g. RS485 on another side. I planned to connect negative battery terminal (0V) directly to the chassis, to provide common potential (negative battery terminal: 0V) for every PCB and improve EMI in terms of radiated emission and immunity. Could it be problematic/dangerous because of ESD? There is no legal requirements about earthing such devices. We can assume, that underground pipes could be grounded. Nevertheless, should I add some earthing point on the ch assis?

My latest video on how to design the PDN for low EMI is out, and you can watch it here: https://youtu.be/5yUmlSl6JUI Please leave a like on the YouTube video, to continue supporting more free content ;) Enjoy! Dario