So, I LOVE my sound saber, and I'm fine with having to recharge the batteries every once and a while. I have one little issue though: I'm afraid of blowing up. Whenever I start to recharge my batteries, (li-on setup, of course), I put them in the rehcarger, and for some time afterwards, it makes a rather loud and scary buzzing sound. It seems to go away after a while, but I'm still afraid that the batteries will suddenly explode or start a fire or something. It's a tad irrational, but I just wanna make sure that the quiet buzzing is normal, and not going to blow me up. Thanks!
I've got a few US chargers and none of them make any noise. I would suggest emailing US and seeing if this is an issue. Good luck!