Construction Machine Management System

A construction machine management system provided with a management device that is disposed in a position away from a construction machine including an electricity storage device and a communication device and manages the electricity storage device by receiving information of the electricity storage device transmitted through the communication device from the construction machine, characterized in that:

• the information of the electricity storage device includes:
• information including a maximum value and a minimum value of respective voltages in a plurality of battery cells configuring the electricity storage device;
• or
• information including a maximum value and a minimum value of respective charging rates in the plurality of battery cells, and
• the management device:
• stores the maximum value and the minimum value, and discharge characteristics of the electricity storage device;
• calculates an estimation maximum value and an estimation minimum value in the present or in the future by adding the discharge characteristics stored in the management device to the latest maximum value and the latest minimum value stored in the management device;
• and
• outputs information based upon the calculated estimation maximum value and the calculated estimation minimum value.