A battery cell stack comprising: a plurality of stacked bipolar plates; battery cells placed between the individual bipolar plates; and a current collector plate electrically connected to each of a pair of end bipolar plates located at both ends in the stacking direction among the plurality of bipolar plates, wherein the corrosion potential difference between any two members in contact with each other between the current collector plate and the end bipolar plate is either: (i) 0.35 V or less, or (ii) 0.45 to 0.55 V, and the corrosion potential difference between any two members in contact with each other means the potential difference between the potential of one material and the potential of another material in artificial seawater (JIS Z 0103 1057), and the potential of each material is a potential relative to the standard hydrogen electrode, wherein two members in contact with each other between the current collector plate and the end bipolar plate are made of materials such that, when an accelerated test satisfying the following conditions 1 to 3 is performed, the electrical resistance value between the current collector plate and the end bipolar plate after the accelerated test is 1.05 times or less the electrical resistance value between the current collector plate and the end bipolar plate before the accelerated test: Condition 1 is that a cycle includes applying pressure to the inside of the battery cell stack over one minute to achieve a predetermined pressure, maintaining the predetermined pressure for one minute, and bringing the predetermined pressure back to the atmospheric pressure over one minute; Condition 2 is that the predetermined pressure is set to be the atmospheric pressure + 0.1 MPa; and Condition 3 is that the number of cycles is set to 18. a plurality of stacked bipolar plates; battery cells placed between the individual bipolar plates; and a current collector plate electrically connected to each of a pair of end bipolar plates located at both ends in the stacking direction among the plurality of bipolar plates, wherein the corrosion potential difference between any two members in contact with each other between the current collector plate and the end bipolar plate is either: (i) 0.35 V or less, or (ii) 0.45 to 0.55 V, and the corrosion potential difference between any two members in contact with each other means the potential difference between the potential of one material and the potential of another material in artificial seawater (JIS Z 0103 1057), and the potential of each material is a potential relative to the standard hydrogen electrode, wherein two members in contact with each other between the current collector plate and the end bipolar plate are made of materials such that, when an accelerated test satisfying the following conditions 1 to 3 is performed, the electrical resistance value between the current collector plate and the end bipolar plate after the accelerated test is 1.05 times or less the electrical resistance value between the current collector plate and the end bipolar plate before the accelerated test: Condition 1 is that a cycle includes applying pressure to the inside of the battery cell stack over one minute to achieve a predetermined pressure, maintaining the predetermined pressure for one minute, and bringing the predetermined pressure back to the atmospheric pressure over one minute; Condition 2 is that the predetermined pressure is set to be the atmospheric pressure + 0.1 MPa; and Condition 3 is that the number of cycles is set to 18. Condition 1 is that a cycle includes applying pressure to the inside of the battery cell stack over one minute to achieve a predetermined pressure, maintaining the predetermined pressure for one minute, and bringing the predetermined pressure back to the atmospheric pressure over one minute; Condition 2 is that the predetermined pressure is set to be the atmospheric pressure + 0.1 MPa; and Condition 3 is that the number of cycles is set to 18.