It appears Olympus has made the BLN-1 battery very proprietary. There are some aftermarket semi-copies out there, but they require their own charger, and will not charge in the OEM charger. I really do not wish to carry two chargers and have to pay attention as to which battery is inserted into which charger. It has something to do with "decoding" the battery/charger, i.e. they "talk" to one another with unique handshaking. I suspect it goes beyond the new law in Japan. All this would not be so bad, but presently there is not a BLN-1 battery available anywhere, at any price in the U.S.