I've now gone through 2 of these chargers. The first one appeared to have overheated while charging 2 AA batteries; fortunately, it died within the 30 day return period, and Amazon proptly sent me a new one. The 2nd unit failed after about 6 months, and so far, I have not received any response from Ansmann USA or Ansmann DE regarding the warranty (which is supposedly 3 years). The 2nd unit appears to have overheated as well. All-in-all, it was a waste of money.