Commercial Fixed Wing
Maintenance Airframe; Maintenance Powerplant
Distraction; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Environment - Non Weather Related; Human Factors
While complying with the return to service from short term storage task card; there was a step to install APU battery; main battery; and the fly by wire backup battery. I had installed the main battery and the APU battery and signed off the task card block accidentally overlooking the step to install the fly by wire backup battery. The fly by wire backup battery was not installed.A lack of concentration and ensuring that all of the work performed had been properly performed is what led to the fly by wire backup battery not being installed.More focus and attention to detail when signing off work performed will prevent incidents like this from happening in the future.
Maintenance Technician reported inadvertently not installing a backup battery while complying with a return to service task card.