FP3 does not charge after heavy rain

[AnotherElk]

@maldini

I’m grateful for any advice

You could try to charge the battery with an external charger.

Unable to charge battery

As an example, this universal smartphone battery charger here works for the Fairphone 3 battery: It works because the 2 contact parts are thin enough and stand out enough. So, even if this particular charger might not be available somewhen somewhere, if anybody is in need, just look for universal chargers with similarly shaped contacts.