Originally Posted by Isoprop
No. The USB connection goes thru a charging IC on the board.
I don't know what happens when 5V is applied to the "special" USB connection (record and charge), most probably thru resistors or a regulator. The battery circuitry is certainly not built for 5V. I haven't traced the "special" connection.
I believe the small protection circuit board that comes on each battery typically has over-voltage protection as well as a LVC to protect cell, but I wouldn't want to rely on it! And as you mentioned, that bypasses the desired CC-CV charge cycle provided by the IC on the camera circuit board. I'd be concerned most with the 5V stressing the rest of the camera circuit board components.