We've been using this battery charger for about one year now it's keeping us from buying batteries for our TV remote controls, and other electronics, we also have a Seiko Motion Melody Clock that requires 4 D size batteries, I put the batteries in March of 2016 and now it's mid February the clock is keeping good time, it's playing the melodies and the clock face when it's going though the clock dance with no signs of slowing down. I'm impressed with the long life this charger puts in to these batteries. The charger is easy to use, and we have not had any problems with to this point.Update: 3-20-17: The four D size batteries are still continue to operate our Seiko Motion Melody Clock, it's been one year and the clock continues to keep good time, I'll update when we have to change them out, but for now these batteries are working great.Update: 3-13-18: The same four batteries are still doing their job after two years they've been operating this clock and it's been keeping good time, the double A's are pretty good too cause we use them in our remote controls, and kitchen wall clock and that's been going for a long time now. I'll update my review again when I have to charge them and put them back into the clock, thanks for reading my review.Update: 11-22-2018: I would not have believed this but the original 4 D batteries that I put in the Seiko Motion Melody Clock back in March of 2016 have finally ran out, so that's about 2 years and 8 months, and I replaced them with 4 new ones of the same brand and I expect they'll last just as long, thanks again for reading my review.