A process and system for measuring internal faults in an electrochemical cell is provided. The process for detecting an internal fault in an electrochemical cell includes measuring a voltage difference or a rate of change in voltage difference between a common terminal of a first electrochemical cell and a second electrochemical cell. The first electrochemical cell or second electrochemical cell is accepted based on the measuring, or first electrochemical cell or second electrochemical cell is rejected based on the measure of the internal fault of the electrochemical cell.

A pinhole determination method for a fuel cell includes steps of: blocking air supply to a fuel cell stack by a controller; measuring a cell voltage value of each of unit fuel cells of the fuel cell stack; and determining whether or not a pinhole is present by comparing the cell voltage value with an average cell voltage value.

An energy storage unit for a motor vehicle battery is provided, having an energy store, particularly configured as a battery cell module, for storing and delivering electric power. A measuring device measures electrical properties of the energy store. An evaluation unit, connected to the measuring device, ascertains the operational status of the energy store from the measurement results of the measuring device. An indicator unit is connected to the evaluation unit for depicting the operational status of the energy store. By ascertaining and depicting the operational status and not just the state of charge of the energy store, it is possible to dispense with separate complex measurements when fitting the energy store, so that an energy storage unit can be checked quickly and efficiently when fitted into a motor vehicle.

An inspection method of a fuel battery by using an electrical charge existing in a fuel battery stack includes a supplying step in which the electrical charge is supplied from an external power supply to the fuel battery stack.

A method for screening a lithium ion battery is provided. A number of lithium ion batteries are galvanostatically discharged a to an inflection point voltage at an inflection point of a discharge curve at a first constant current I.sub.1. The number of lithium ion batteries are rested for a first rest time T.sub.1 to raise an open circuit voltage of the number of lithium ion batteries to U.sub.1. U.sub.1 is greater than the inflection point voltage. The number of lithium ion batteries are galvanostatically discharged to the inflection point voltage at a second constant current I.sub.2, in which I.sub.2<<I.sub.1. The number of lithium ion batteries are rested for a second rest time T.sub.2 and the batteries are screened based on a self-discharge of the number of lithium ion batteries.

The present invention relates to a device and method which can measure, in real time, the resistance, depending on pressure changes, of a separator that is immersed in an electrolyte, and enables analysis of the resistance properties of a separator reflecting the real operating state of a secondary battery.

A method of manufacturing a lithium-ion secondary battery of the present invention includes at least four steps as follows: an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to initial charging, under a temperature environment ranging of equal to or higher than −20° C. and equal to or lower than 15° C.; an aging step of leaving the lithium-ion secondary battery under a temperature environment ranging of equal to or higher than 30° C. and equal to or lower than 80° C. after the initial charging step; a short circuit detecting step of detecting the presence or absence of a short circuit of the lithium-ion secondary battery by measuring a voltage drop quantity of the lithium-ion secondary battery and comparing the voltage drop quantity with a reference value; and a sorting step of sorting out a lithium-ion secondary battery in which no short circuit is detected.

The present invention relates to an eddy current sensor for deriving an eddy current and sensing the derived eddy current in order to detect a crack in a battery cell, the eddy current sensor comprising: a core unit in which a coil is wound around a magnetic member; and a case for accommodating the core unit of which there are at least two, and which are respectively arranged so that the central axis of the coil is oriented in the thickness direction of the battery cell. The eddy current sensor of the present invention enables one-point sensing, thereby improving crack detection capability without a non-inspection area while having high detection resolution.

Certain embodiments are described that provide a method and computer readable media for testing battery cells. A unique identifier (e.g., barcode) is affixed to a battery cell which allows it to be tracked across separate tests as a cell, in a module, string, pack, etc. Using a GUI, the unique identifier is recorded in a database along with at least a battery cell manufacturer and a battery cell model. A designation of the particular tester channel or module or string location is entered into the database in association with the unique identifier. Test results of the first test are electronically transferred from the first tester to the database along with the corresponding channel designations.

The present invention relates to a method and an apparatus for diagnosing low voltage of a secondary battery cell. The method for diagnosing low voltage of a secondary battery cell according to an embodiment of the present invention includes pre-aging a battery cell, charging the battery cell according to a preset charging condition, measuring a parameter for determining low voltage failure of the battery cell, comparing the measured parameter with a reference parameter, and performing formation when the battery cell is determined to be normal.