Method for inspecting a power storage device for short circuit, method for manufacturing the power storage device, and method for manufacturing a connected restrained-device module
A method for inspecting a battery for short circuit includes: adjusting batteries, which have been subjected to initial charging and subsequent charging and discharging, to a first device voltage; measuring a pre-leaving voltage; leaving the batteries for a leaving period with terminals in an open state; measuring a post-leaving device voltage; actually measuring an actual measured voltage drop rate; determining whether or not each voltage is short-circuited; and, prior to the determining, estimating an estimating voltage drop rate according to an elapsed time and a leaving period. In the determining, it is determined whether or not each battery is short-circuited using the actual voltage drop rate and the estimated voltage drop rate.
1 . A power storage device inspecting method, comprising:
a voltage adjusting step of adjusting a voltage of a power storage device, which has been initially charged, to a first device voltage by charging or discharging the power storage device;
a pre-leaving voltage measuring step of measuring a pre-leaving device voltage of the power storage device, wherein the pre-leaving device voltage is a voltage of the power storage device before the power storage device is left standstill;
a leaving step of leaving the power storage device, that has been measured for the pre-leaving device voltage, standstill for a leaving period with terminals of the power storage device in an open state;
after the leaving step, a post-leaving voltage measuring step of measuring a post-leaving device voltage of the power storage device, wherein the post-leaving device voltage is a voltage of the power storage device after the power storage device has been left standstill in the leaving step;
an actually measuring step of obtaining an actual measured voltage drop rate of the power storage device between the pre-leaving device voltage and the post-leaving device voltage;
an estimating step of estimating an estimated voltage drop rate to be generated in the power storage device according to
an elapsed time from completion of voltage adjustment in the voltage adjusting step until start of measurement of the pre-leaving device voltage in the pre-leaving voltage measuring step, and
the leaving period;
after the estimating step, a short-circuit determining step of determining whether or not the power storage device is short-circuited, based on the actual measured voltage drop rate and the estimated voltage drop rate; and
an eliminating step of eliminating the power storage device that is determined to be short-circuited in the short-circuit determining step.
2 . The power storage device inspecting method according to claim 1 , wherein
the power storage device is one among a plurality of power storage devices,
the power storage device inspecting method further comprises:
after the voltage adjusting step but before the pre-leaving voltage measuring step,
a restraining step of restraining, by a restraining member, the plurality of power storage devices each having been adjusted to the first device voltage, while the power storage devices are electrically unconnected to each other, to constitute a restrained-device module including a plurality of restrained devices which are the power storage devices restrained by the restraining member, and
the pre-leaving voltage measuring step, the leaving step, and the post-leaving voltage measuring step are performed on the restrained devices included in the restrained-device module.
3 . A connected restrained-device module manufacturing method, comprising:
a short-circuit inspecting step of inspecting, by the power storage device inspecting method according to claim 2 , whether or not each of restrained devices included in a restrained-device module is short-circuited; and
a connecting step of electrically connecting the restrained devices included in the restrained-device module to each other, in response to the short-circuit inspecting step determining that all of the restrained devices included in the restrained-device module are not short-circuited.
4 . The connected restrained-device module manufacturing method according to claim 3 , further comprising:
a removing step of removing at least one restrained device, that has been determined to be short-circuited in the short-circuit inspecting step, from among the restrained devices included in the restrained-device module; and
a re-restraining step of reconstituting the restrained-device module from (a) remaining restrained devices, that have been determined not to be short-circuited in the short-circuit inspecting step, together with (b) a supplementary power storage device, the supplementary power storage device having been included in another restrained-device module and determined not to be short-circuited.