Happy holidays from Washington DC!
I’m working on a small electronics project with my sons and could use some insight on a unexpected snag after encapsulating our PCB with a polyurethane resin. We created a small printed circuit board (PCB) and soldered it with a Micro ATTiny85 and Adafruit LoRa module as part of a small receiver. We then separately connected the PCB to a 3V coin battery and LED which lights up when receiving a LoRa signal. It works perfectly. The snag came in when we covered just the PCB with a polyurethane resin from Electrolube which claims to be perfect for electronic potting. The PCB and LED worked after the resin cured but we were surprised that after only 1 day the battery voltage dropped from 3.2V to 1.3V. Yes the battery was connected to the PCB but we certainly didn’t think the battery life would drop so much by simply having it wired to the PCB. Do such coatings drain batteries that fast or should we use a different approach to weatherproof our PCB??