"This is an identification guide for Nitecore charger users. There are two approaches:
Tool: a tiny magnet
Procedure: Place the magnet on the metal surface (battery contacting points or sliders) of the charger.
Reference: A legitimate Nitecore charger does not attract the magnet, while a counterfeit charger does the opposite.
Physics behind: The battery contacting points and sliders of a legitimate Nitecore charger are made from pure copper, a non-magnetic material with high electrical conductivity. Therefore Nitecore chargers do not attract magnets. The battery contacting points and sliders of counterfeit chargers are mostly made from iron, a material with poor corrosion resistance and electrical conductivity, and easily attaches to magnets."
Parece que en el mío, el imán se une con fuerza al negativo, no así al positivo. ¿Vuestras experiencias?