Abstract: The disclosure provides a battery device, a detection method thereof, and a screening method and device of a battery unit. A difference between characteristic values of any two battery units within a preset range is controlled. The characteristic value reflects the difference between polarization internal resistances of different battery units, thereby reflecting the consistency difference between different battery units. The solution can dynamically monitor the consistency of each battery unit in the battery device, which can reflect the consistency of the battery unit during the usage process to implement the online monitoring of the battery unit, thereby providing guidance for the subsequent use of the battery device.

Abstract: The invention discloses a battery device, a detection method thereof, and a screening method and device of a battery unit. A difference between characteristic values of any two battery units in the target charge state within a first preset range is controlled. Through the difference in overpotential of different battery units, the polarization difference between different battery units is reflected, thus reflecting the consistency difference between different battery units. The solution may dynamically monitor the consistency of various battery units, which may reflect the consistency of the battery unit during use, realize the online monitoring of the battery unit, and provide guidance for use of the battery device in subsequent process.

Abstract: The present disclosure provides a method for measuring an internal resistance of a battery, after discharging/charging the battery under a preset constant-current, acquiring voltages of the battery within a period from ending the discharging/charging to a time when the voltage reaches stable, and then calculating different corresponding internal resistances caused by ohmic polarization, electrochemical polarization and concentration polarization separately. Since it is different for the orders of the magnitude of the characteristic time which these different polarizations need to get back into new equilibrium state after ending the discharging/charging, the method of the present disclosure classifies the internal resistances caused by these polarizations and calculated different internal resistances corresponding to the polarizations.

Abstract: The present disclosure provides a method for measuring an internal resistance of a battery, after discharging/charging the battery under a preset constant-current, acquiring voltages of the battery within a period from ending the discharging/charging to a time when the voltage reaches stable, and then calculating different corresponding internal resistances caused by ohmic polarization, electrochemical polarization and concentration polarization separately. Since it is different for the orders of the magnitude of the characteristic time which these different polarizations need to get back into new equilibrium state after ending the discharging/charging, the method of the present disclosure classifies the internal resistances caused by these polarizations and calculated different internal resistances corresponding to the polarizations.