I dunno. Mine are 2+ years old, used almost daily. Got 5+ hours last time out on 2 internals...
Bought a pair of new ones to go with my 2 Wally/V3 batteries. I'm figuring 11+ hours now between charges, in a small lightweight form-factor (with 2 EC-90 boat anchors in the car for backup, gives me close to 24 hours of recording capability)...
Rick