Patent ID: 7052105

Claim:
A battery residual capacity detection method in a printing apparatus operable with at least a battery power source, said method comprising: a detection step of detecting a battery voltage thereby detecting a battery residual capacity while printing is performed on a printing medium by reciprocate-scanning a printhead mounted on the printing apparatus; a determination step of determining whether or not the battery residual capacity detected at said detection step is equal to or less than a predetermined threshold value; and a detection control step of controlling driving of a carriage motor to reciprocate-scan the printhead and driving of a conveyance motor to convey the printing medium so as to provide a time zone where a load on the carriage motor and that on the conveyance motor do not overlap in accordance with the determination result at said determination step, and controlling said detection step so as to detect the battery residual capacity in the time zone where the loads do not overlap, wherein the time zone in which the loads do not overlap includes a time zone after excitation to stop the conveyance motor to stop conveyance of the printing medium and before driving of the carriage motor to move the printhead.