A secondary battery pack including (a) a secondary battery block comprising a plurality of unit blocks (2, 19) connected in series, wherein each unit block comprises a plurality of secondary batteries connected in series; (b) battery adjustment sections (5, 20) that are each provided for each of the unit blocks, are connected to each secondary battery in the unit blocks, and have a function of monitoring the voltage of the secondary batteries; (c) a charge switch that is configured to break a charge path inserted into a charge and discharge path of the secondary battery block; (d) a discharge switch that is configured to break a discharge path inserted into the charge and discharge path; (e) a current detection section that is configured to monitor a charge and discharge current of the secondary battery block, (f) transmission sections (17, 21) that are each provided for each of the unit blocks, are connected to the respective battery adjustment sections, and are configured to receive information from the battery adjustment sections, wherein (g) each transmission section is connected to the transmission sections provided for the preceding or subsequent unit blocks, and is configured to output at least either information input from the preceding transmission sections or information input from the respective battery adjustment sections to the subsequent transmission sections, (h)the current detection section is configured to input its output to the battery adjustment section provided for the unit block closest to the charge and discharge path, and the battery adjustment section or the transmission section (17, 21) connected to the battery adjustment section has means configured to determine whether the output from the current detection section is in an abnormal state, (i) the transmission sections comprise a constant current transmission circuit comprising a constant current transmission function and configured to transmit, in the abnormal state, with a constant value of current, wherein the transmission sections comprise a voltage detection circuit comprising a current detection function to detect the value of the constant current, a high-resistance circuit and an OR circuit, (j) wherein the constant current transmission circuit is configured to input the constant current from the constant current transmission function of the transmission section to the high-resistance circuit, (k) wherein the voltage detection circuit is configured to detect the value of the constant current by detecting the voltage at both terminals of the high-resistance circuit and configured to output a resultant information to the OR circuit, (l) wherein the OR circuit is configured to output abnormal information when the battery adjustment section or the preceding transmission section is in the abnormal state. (a) a secondary battery block comprising a plurality of unit blocks (2, 19) connected in series, wherein each unit block comprises a plurality of secondary batteries connected in series; (b) battery adjustment sections (5, 20) that are each provided for each of the unit blocks, are connected to each secondary battery in the unit blocks, and have a function of monitoring the voltage of the secondary batteries; (c) a charge switch that is configured to break a charge path inserted into a charge and discharge path of the secondary battery block; (d) a discharge switch that is configured to break a discharge path inserted into the charge and discharge path; (e) a current detection section that is configured to monitor a charge and discharge current of the secondary battery block, (f) transmission sections (17, 21) that are each provided for each of the unit blocks, are connected to the respective battery adjustment sections, and are configured to receive information from the battery adjustment sections, wherein (g) each transmission section is connected to the transmission sections provided for the preceding or subsequent unit blocks, and is configured to output at least either information input from the preceding transmission sections or information input from the respective battery adjustment sections to the subsequent transmission sections, (h)the current detection section is configured to input its output to the battery adjustment section provided for the unit block closest to the charge and discharge path, and the battery adjustment section or the transmission section (17, 21) connected to the battery adjustment section has means configured to determine whether the output from the current detection section is in an abnormal state, (i) the transmission sections comprise a constant current transmission circuit comprising a constant current transmission function and configured to transmit, in the abnormal state, with a constant value of current, wherein the transmission sections comprise a voltage detection circuit comprising a current detection function to detect the value of the constant current, a high-resistance circuit and an OR circuit, (j) wherein the constant current transmission circuit is configured to input the constant current from the constant current transmission function of the transmission section to the high-resistance circuit, (k) wherein the voltage detection circuit is configured to detect the value of the constant current by detecting the voltage at both terminals of the high-resistance circuit and configured to output a resultant information to the OR circuit, (l) wherein the OR circuit is configured to output abnormal information when the battery adjustment section or the preceding transmission section is in the abnormal state.