I wanted to use rechargeables (good performance and inexpensive) and keep this in my briefcase as a backup charger.That was the theory. if you use anything other than lithium (very expensive) or alkaline (Poor performance) the positive contact will not touch. (I tried 6 different brands of rechargeables)I ended up taking it apart (disassembly is fairly easy) to put a solder blob on the positive terminal. Now it makes contact with my NiMH batteries but the battery cover on this thing is really flimsy. Add to that the blinking blue light - certainly gets your attention but it ends up being VERY annoying. I tried to charge my Moto Q in my car (while using a BT headset) and I had to cover the charger with my coat.I ended up buying a noname made in China charger for less than half the price, it has a screw on battery cover and a red LED rather than these super bright blinking blue ones. And of course, it accepted rechargables with no modifications.Basically there are better designed products out there for a lot less.