A secondary battery configured to effectively estimate the life or degradation of the secondary battery as the secondary battery degrades includes a packaging material, an electrode assembly, a first electrode lead, a second electrode lead, a first measuring lead, and a second measuring lead. The electrode assembly includes a stack having a plurality of first electrode plates at respective first locations within the stack and a plurality of second electrode plates at respective second locations within the stack, the first and second locations alternating with one another and having a separator interposed between each of the first and second locations. The electrode assembly further includes a first measuring plate and a second measuring plate having the same polarity as the first electrode plates and located at at least one of the first locations within the stack.

A method for characterizing at least one joined connection between at least two components, whereby an eddy-current sensor is consecutively moved several times over the at least one weld, thereby generating a plurality of data sets of the detected measuring signals in various parallel sectional planes of the weld, and whereby, on the basis of the plurality of data sets, a projection data set is subsequently determined as the measure of the spatial distribution of the measuring signals along the at least one joined connection.

A method for characterizing at least one joined connection between at least two components, whereby an eddy-current sensor is consecutively moved several times over the at least one weld, thereby generating a plurality of data sets of the detected measuring signals in various parallel sectional planes of the weld, and whereby, on the basis of the plurality of data sets, a projection data set is subsequently determined as the measure of the spatial distribution of the measuring signals along the at least one joined connection.

The current sensor includes a battery terminal part that has electrical conductivity and is fastened to a battery post constituting a negative electrode of a battery, and a shunt resistor that is conductively connected to the battery terminal part via a joint part, the shunt resistor including a first detection terminal and a second detection terminal for detecting an electric current. The battery terminal part includes a third detection terminal for detecting a voltage of the battery between the joint part and the battery post. As a result, the current sensor can properly detect a voltage of the battery together with an electric current.

The current sensor includes a battery terminal part that has electrical conductivity and is fastened to a battery post constituting a negative electrode of a battery, and a shunt resistor that is conductively connected to the battery terminal part via a joint part, the shunt resistor including a first detection terminal and a second detection terminal for detecting an electric current. The battery terminal part includes a third detection terminal for detecting a voltage of the battery between the joint part and the battery post. As a result, the current sensor can properly detect a voltage of the battery together with an electric current.

In a DC impedance measurement routine for a battery the current load from a source is initially set to a low setting. The system waits for a set time in this state for the voltage readings to stabilize. Once the voltage is stable at the low current setting, the current setting is changed to a high value and the voltage is read quickly. Then the current load is set back to the low setting immediately after the reading is made. Several consecutive measurements are performed by repeating the steps above. A DC impedance measurement system that can be used to carry out the measurement routine. A multi-battery system can be monitored via a DC impedance measurement system and the routine being performed on each battery.

In a DC impedance measurement routine for a battery the current load from a source is initially set to a low setting. The system waits for a set time in this state for the voltage readings to stabilize. Once the voltage is stable at the low current setting, the current setting is changed to a high value and the voltage is read quickly. Then the current load is set back to the low setting immediately after the reading is made. Several consecutive measurements are performed by repeating the steps above. A DC impedance measurement system that can be used to carry out the measurement routine. A multi-battery system can be monitored via a DC impedance measurement system and the routine being performed on each battery.

A current sensor includes a battery terminal portion that is conductive and is fastened to a battery post that extends along a first direction; a sensor unit that is located side by side with the battery terminal portion along a second direction that intersects the first direction and is electrically connected to the battery terminal portion to detect a current; and a housing that has an insulating property and embeds the sensor unit, in which the battery terminal portion includes a pair of plate-shaped portions, and the pair of plate-shaped portions are embedded in the housing with end portions on the sensor unit side in the second direction spaced apart from each other along the first direction.

A semiconductor device that is of a face-down mounted chip-size package type, discharges electric charges stored in an electric storage device (battery), and has a power loss area ratio of at least 0.4 (W/mm.sup.2) obtained by dividing a power loss (W) in the semiconductor device at time of the discharge by an area (mm.sup.2) of the semiconductor device, the semiconductor device comprising: a field-effect transistor of a horizontal type and a resistor that are connected in series in stated order between an inflow terminal and an outflow terminal; and a control circuit that causes a discharge current to be constant without depending on an applied voltage between the inflow terminal and the outflow terminal. A difference between a maximum temperature of a field-effect transistor portion and a temperature of a resistor portion is within five degrees Celsius in a discharge period.

A semiconductor device that is of a face-down mounted chip-size package type, discharges electric charges stored in an electric storage device (battery), and has a power loss area ratio of at least 0.4 (W/mm.sup.2) obtained by dividing a power loss (W) in the semiconductor device at time of the discharge by an area (mm.sup.2) of the semiconductor device, the semiconductor device comprising: a field-effect transistor of a horizontal type and a resistor that are connected in series in stated order between an inflow terminal and an outflow terminal; and a control circuit that causes a discharge current to be constant without depending on an applied voltage between the inflow terminal and the outflow terminal. A difference between a maximum temperature of a field-effect transistor portion and a temperature of a resistor portion is within five degrees Celsius in a discharge period.