A printing apparatus comprising: a printing unit configured to print received information on a recording sheet; a power supply including a rechargeable battery ; a charger , coupled to the power supply , and configured to charge the rechargeable battery , wherein the charger includes a charging circuit , a setting circuit configured to receive a feedback voltage from the rechargeable battery and a charging voltage from the charging circuit , and a first switch coupled to the charging circuit ; a second switch ; and a diode coupled in parallel to the second switch , wherein the second switch and the diode are coupled to the rechargeable battery , wherein, in a state where the feedback voltage from the rechargeable battery is supplied to the setting circuit , the setting circuit closes the first switch , the voltage from the rechargeable battery causes a reverse voltage to be applied to the diode , and the voltage from the rechargeable battery causes a forward voltage to be applied to the second switch and close the second switch , to supply power from the rechargeable battery to the printing unit , and wherein, in a state where the charging voltage from the charging circuit is supplied to the setting circuit , the setting circuit opens the first switch , the charging voltage from the charging circuit causes a forward voltage to be applied to the diode , and the charging voltage from the charging circuit causes a reverse voltage to be applied to the second switch and open the second switch , to charge the rechargeable battery by a current flowing through the diode and supply no power from the rechargeable battery to the printing unit . a printing unit configured to print received information on a recording sheet; a power supply including a rechargeable battery ; a charger , coupled to the power supply , and configured to charge the rechargeable battery , wherein the charger includes a charging circuit , a setting circuit configured to receive a feedback voltage from the rechargeable battery and a charging voltage from the charging circuit , and a first switch coupled to the charging circuit ; a second switch ; and a diode coupled in parallel to the second switch , wherein the second switch and the diode are coupled to the rechargeable battery , wherein, in a state where the feedback voltage from the rechargeable battery is supplied to the setting circuit , the setting circuit closes the first switch , the voltage from the rechargeable battery causes a reverse voltage to be applied to the diode , and the voltage from the rechargeable battery causes a forward voltage to be applied to the second switch and close the second switch , to supply power from the rechargeable battery to the printing unit , and wherein, in a state where the charging voltage from the charging circuit is supplied to the setting circuit , the setting circuit opens the first switch , the charging voltage from the charging circuit causes a forward voltage to be applied to the diode , and the charging voltage from the charging circuit causes a reverse voltage to be applied to the second switch and open the second switch , to charge the rechargeable battery by a current flowing through the diode and supply no power from the rechargeable battery to the printing unit . <EOS>