Got myself this battery of Ayex and Hahnel HL-S5 Replacement Battery for Olympus OM-D EM 10. During Hähnel battery can be used properly in exchange with the original battery from Olympus, does the Ayex BLS-5 Battery very unreliable. Although it fits properly in the camera body, but it is relatively frequent that it is not recognized by the camera to power up. This is very annoying and usually then only be repaired by exchange for the original battery or the battery Hahnel, the plugging and unplugging of Ayex batteries does not help in such a case then, the camera will no longer responding. Therefore, for practical use in connection with the Olympus OM-D EM 10 unusable. Like the other positive reviews show he seems better harmonize with other camera models.