Battery module state detection method

摘要

The present invention provides a battery module state detection method. The battery module includes a battery unit and is connected to a load. The method for detecting the battery module status includes the following steps. First, measure an on-load voltage value of the battery unit and a load current value of a load. Next, calculate an instant resistance value of the battery unit according to a no-load voltage value of the battery unit, the on-load voltage value and the load current value. Finally, obtain an operating state of the battery unit according to the instant resistance and a relationship between the internal resistance and discharging time. By the method of the present invention, the user can monitor the remaining energy of the battery module accurately in real time and therefore prevent the electrical hazard caused by over-discharging the battery module.

主权项

1. A battery module state detection method applied to a battery module state detection device (1) for a battery module,
the battery module comprising one or more lithium iron phosphate battery unit of an initial internal resistance value and being connected to a load, the battery module state detection device (1) comprising:
a detecting unit (11), comprising a plurality of test terminals connecting respectively a positive electrode and a negative electrode of the battery unit for measuring an on-load voltage value and a no-load voltage value of the battery unit,a shunt (12), anda control unit (10) for obtaining an internal resistance value of the battery, the battery module state detection method comprising the following steps of: (a) measuring an on-load voltage value of the battery unit and a load current value of the load; (b) calculating an instant internal resistance value of the battery unit by first subtracting the on-load voltage value from the no-load voltage value, and then dived by the load current; (c) obtaining an operating state of the battery unit according to the instant internal resistance value and a relationship between internal resistance and discharging time; (d) obtaining a numerical value of a quality reference by dividing the instant internal resistance value with the initial internal resistance value of the battery unit, with the numerical value of the quality reference value initialized to 1 when the battery unit is just about to discharge for the first time; (e) defining a safe remaining energy value of the battery module as the lowest of the numerical value of the quality reference obtained for the one or more battery unit; and activating a protection mechanism for the quality reference value exceeding a preset threshold value greater than 1.