My experience with the $20 kit offering two BLN-1 equivalent batteries plus a charger and a souvenir lanyard was most likely a waste of the $20. The Olympus BCN-1 charger signals error when I try to charge them. I could fool it a bit, but didn't get a full charge. The Wasabi/Kappaken charger has only two pins, (the battery has five, Oly cameras have three). This means that charging is openloop, never a good idea with Li-ion batteries. Those extra pins monitor temperature and open circuit voltage so that charging can stop when the battery is full.
Amazon product reviews, however, are all pretty good. So has anyone here tried them and with what results?