A method and apparatus for repairing or testing a used battery pack from an electric vehicle include removing the battery pack from the vehicle. Battery tests are performed on at least some of the plurality of batteries and battery test results for each of the batteries tested are obtained. A cradle is configured to receive at least two different types of batteries. The cradle includes connectors to electrically couple circuitry of a battery tester to the battery.

A method and apparatus for repairing or testing a used battery pack from an electric vehicle include removing the battery pack from the vehicle. Battery tests are performed on at least some of the plurality of batteries and battery test results for each of the batteries tested are obtained. A cradle is configured to receive at least two different types of batteries. The cradle includes connectors to electrically couple circuitry of a battery tester to the battery.

A battery testing apparatus includes a battery cycler configured to position a battery cell in a cell pocket defined by a baseplate. The apparatus additionally includes a thermal control device configured to regulate thermal energy in the cell pocket, a baseplate thermistor for detecting baseplate temperature, and thermal control device thermistor for detecting thermal control device temperature. The apparatus also includes a printed circuit board (PCB) in electric communication with the thermal control device thermistor. An electronic microcontroller, in electric communication with the baseplate thermistor and the PCB, is configured to regulate operation of the thermal control device based on data from the baseplate thermistor and the thermal control device thermistor. A main controller, in electronic communication with the microcontroller, is programmed to establish set values for baseplate temperature and battery cell reference current or voltage and regulate electrical input to the battery cell in accordance with the reference values.

A method for diagnosing a battery pack having a configuration in which a plurality of cells are connected in series uses a system for obtaining detected data including the current and temperature of the battery pack and the voltage of each cell. An electric charge capacity and a state of charge (SOC) of each cell is calculated using the current and the temperature, the voltage of each cell, an open circuit voltage (OCV)-SOC function, and an OCV-resistance table. An amount of unbalance, which is an estimated value of the SOC, and the resistance for each cell when the battery pack is fully charged is calculated; and the energy capacity of the battery pack using the electric charge capacity, the amount of unbalance, and the resistances are calculated. As a result, the energy capacity of the battery pack can be calculated accurately, even in an unbalanced state.

A failure detection apparatus includes: a first switch configured to be connected to a positive electrode of a battery; a second switch configured to be connected to a negative electrode of the battery; detection resistances that are connected in series between the first switch and the second switch; and a measurement circuit that measures a voltage of the detection resistances, wherein (i) both the first switch and the second switch are turned on to form a failure-detection series-connected circuit consisting of the battery and the detection resistances, and (ii) a failure detection mode is provided to detect a failure based on the voltage measured by the measurement circuit.

A failure detection apparatus includes: a first switch configured to be connected to a positive electrode of a battery; a second switch configured to be connected to a negative electrode of the battery; detection resistances that are connected in series between the first switch and the second switch; and a measurement circuit that measures a voltage of the detection resistances, wherein (i) both the first switch and the second switch are turned on to form a failure-detection series-connected circuit consisting of the battery and the detection resistances, and (ii) a failure detection mode is provided to detect a failure based on the voltage measured by the measurement circuit.

Kelvin (4-wire) connecting cables are routinely used when performing dynamic measurements (i.e., measurements with time-varying signals) on electrochemical cells and batteries. Current-carrying and voltage-sensing conductor pairs within such cables comprise distributed-parameter two-wire transmission lines which may extend several meters in length. As with all such transmission lines, internally reflected waves can oscillate back and forth at high frequency (hf) whenever the lines are not terminated in their characteristic impedances. Such hf reflected waves, by interacting with measuring circuitry, can seriously degrade low-frequency measurement accuracy. Apparatus is disclosed herein that suppresses hf reflected waves oscillating on Kelvin connecting cables during dynamic measurements of cells and batteries.

A method and device for testing a battery that powers a body-wearable medical device. The battery is contacted via battery contacts and a capacitor is arranged in parallel with the battery contacts. During the battery test, a first capacitor voltage U1 is determined at a first time t1 and a second capacitor voltage U2 is determined at a second time t2 subsequent to time t1. A test current is drawn between time t1 and time t2. t1 is determined by the beginning of drawing the test current and time t2 is determined such that the capacitor voltage at time t2 is in a steady state and is substantially constant while the test current is being drawn. A charging state of the battery is determined from the difference in voltage between U1 and U2 and/or from a time difference between the time t1 and time t2.

The disclosure relates to accurately determining a DC energy signal, such as a DC current or DC voltage, which may be particularly useful when controlling a formation/testing current of a battery cell during formation and/or testing. In the battery formation/testing context, a current sensor is used to measure the current of the battery cell, which is used as a feedback signal for controlling the current to achieve a target current. The transfer function of the current sensor is used to improve the accuracy of the current measurement. Because the transfer function can be regularly determined during formation/testing, a lower-cost current sensor with relatively poor temperature coefficient may be used. Any change in the gain of the current sensor may be detected by the transfer function determination and corrected for. Therefore, high current control accuracy may be achieved at lower cost.

A plurality of batteries is stacked, together with spacers, in a compressed state. Charging and discharging units are arranged facing lead terminals protruding from the batteries and are independently operable for the respective batteries. The charging and discharging units each independently include substantially V-like shaped power-side and measurement-side contact elements elastically supported by compression coil springs and having floating freedom. When the batteries are moved all together toward the charging and discharging units, front end surfaces of the lead terminals are pressed against and electrically connected to flat surfaces of the power-side and measurement-side contact elements. By this, it is possible to smoothly perform charging and discharging inspection on the batteries even when the lead terminals protruding from the battery package are subjected in advance to surface treatment.