The Battery DA is programmed to "lose" the lightning bolt when the battery goes into trickle charge. This isn't an intuitive course for the Battery DA to follow. The user's manual on page 96 says that "when the power adapter is plugged in, the Battery DA will show a lightning bolt through the battery graphic." This is not happening.
The PowerBook user manuals are being updated to address errors that were discovered, including the one you've identified. Current product inventory will still have the original manuals.