Electrical outlets in Cuba

I did not think Cuba would have support for the North American standard electrical outlets. Well, I was wrong. The Ancon resort I stayed at has these funky outlets. They have the three round holes for the Cuban standards but upon close inspection they also have holes that match the North American 110/220V electrical plug configuration. So if anyone travels to Cuba, just bring your battery charger.

I did not bring my charger along but I did bring three batteries for my camera. Two of them worked as I expected -- the original Nikon battery and the third-party vertical grip. They were good enough for over 1000 actuations. The third battery (i.e. the cheap EN-EL3 battery I have been complaining about) has now been dissected on my table. It contains two blue large batteries -- a bit wider than the AA batteries. Each blue battery carries 4 volts. They are serially connected to give 8 volts. There is an electronic circuit board that controls the output of the battery package. It would seem that the circuit board is faulty. While I can measure 8 volts from these two batteries, the + electrode connected to the circuit board measures 0 volt.