The noise is usually the fan, plus the induction circuit, but very low btw and only when charging in my experience. Reality unfortunately is that wireless charging is a big advertising scam. Samsung declares for its 15w fast wireless charger 2.0 that it's capable of charging my Note 20 Ultra in about 2 hours. I bought one (current model EP-P2400) and gave it a try. I expected it being less efficient than wired charging but... This is beyond unfair advertising... Since the heat, the charger is soon reducing charge speed from top 3a 4v = 12w to about 200 ma, making the charging ridiculously slow even with fast charging enabled and fan running. In normal summer weather here, 30+ Celsius degrees, it is impossible to have the phone cold enough to fast charge. It soon gets to 38+ degrees and wireless charging reduces as I told before. I also tried charging the phone while off. In 2 hours it only got to 60%. I was even thinking the new charger was broken but, then, I put the phone in the fridge for some minutes, took it to 15 degrees and it magically started to wireless charge at 3a 4v as expected. Not 15w but at least 12w. That could be the phone max. So, summarizing, the advertised 2 hours full charge are only true if you charge in Iceland during winter time. Shame on them for such a scam. I will never buy one of this traps anymore. Use wired chargers guys!
