Trustfire chargers making humming noise


Hi all. I would like to know if it’s normal for this trustfire chargers to make a humming noise…


Hello Kyril,

Is it only humming when it is charging batteries or even when it just plugged in?

Also be sure to charge batteries on 3.0v and not 4.2v.

Also is it both chargers or just one of them? Can you further describe this humming noise?


i dont hear now when i plug in w/o battery. but it does while charging yesterday. still i finish charging all those battery though. the humming noise are slow but noticeable