At first I had a low-priced USB cable, the advantage here is that the 3DS also can load on your PC or car charger. Unfortunately the cable was broken after about 1/2 year.
After that, I got me a discount by 5 charger, not original. While playing a charge was not possible, the device is always jumping between "invites" and "not charging" (I think the tension was wrong), in the off-state, it was not a problem.
Now I have yet invested 3 more and gained me a original charger. Everything is great here. Loads quickly and easily in any condition, device is not hot OAU, as I expect from an original me.
My Emfehlung: saves you the frustration with cheaper replicas, take equal the original (even if I do not understand why Nintendo does not simply attaches a charger for 3DS)