The appointed battery is precisely in terms of battery performance (duration of use) at the time as the original. But the Sennheiser station does not recognize him exactly as the original. This means that the indicator lights "red" for "empty battery is at the onset of this battery does not indicate the original battery already. The green light for" Loading / fully charged "but works. But that does not detract from the power yes, so far as we are currently completely satisfied.