ELECTRIC STORAGE DEVICE

Abstract

ELECTRIC STORAGE DEVICE:[Problem to be Solved]To provide an electric storage device that can provide notification of information regarding immersion to the outside. [Solution]An optional storage device includes: a plurality of battery packs (5) mounted to be aligned in an up-down direction within a columnar member (2); a control device (6) arranged above the battery packs (5) and controlling the battery packs (5); an immersion sensor (56) provided in each of the plurality of battery packs (5); and a notification unit (80) that provides notification of information regarding immersion to the outside.The control device (6) includes a communication unit (71) that receives information indicating immersion from an immersion sensor (56) in each battery pack (5), a determining unit (72) that determines the degree of immersion based on the immersion sensor (56) that has transmitted the received information indicating immersion, and a control unit (73) that controls a notification unit (80) to provide notification of the degree of immersion information indicating the degree of immersion determined by the determining unit (72) to the outside. Figure 1.

Description

Description ELECTRIC STORAGE DEVICE Invention Engineering Field This invention relates to an electrical storage device. Background of the Invention In recent years, various efforts have been made to reuse battery packs installed in vehicles. Because of the problem that such efforts are unprofitable when the battery packs are disassembled into cells and modules, the battery packs are reused as is. However, battery packs using small lithium-ion batteries have a small capacity, making them unsuitable for household electricity. With this in mind, one application for recycling battery packs using small lithium-ion batteries is as a power storage device for streetlights. Furthermore, streetlights can be solar-powered (hereinafter referred to as solar streetlights). Performance such as capacity and internal resistance of battery packs collected from the market deteriorate compared to new battery packs, and performance varies among battery packs. Considering such circumstances, capacity needs to be increased by combining multiple battery packs when reusing battery packs. WO2017 / 029715 discloses a storage battery control device intended for, when an anomaly occurs due to a disaster such as an earthquake, tsunami, wind and flood damage, or fire, releasing electricity stored in the storage battery and reducing the possibility of a secondary disaster occurring compared to the prior art. The storage battery control device includes an electrical control unit that, when it is determined that an anomaly has occurred based on a signal received from an anomaly detection unit, causes an electrical consumption unit to consume electricity stored in the storage battery and reduce the amount of electricity of the storage battery to be equal to or less than a set charge amount. WO2017 / 029715 discloses that the anomaly detection unit is an immersion sensor that detects the presence or absence of water immersion. According to such a configuration, the storage battery controller described in WO2017 / 029715 can detect anomalies resulting from water immersion and discharge the storage battery before the electrical storage system is damaged by water immersion. [Comparison List] [Patent Literature] [Patent Literature 1] WO2017 / 029715 Brief Description of the Invention [Technical issues] However, the storage battery control device described in WO2017 / 029715 has the problem that the information about water immersion (hereinafter referred to as immersion information) cannot be recognized outside the electric storage system. This invention has been made in view of the above, and aims to provide an electrical storage device that can provide notification of external immersion information. [Solution to problem] To achieve the above objectives, the present invention is an electric storage device comprising: a plurality of battery packs capable of supplying electricity to a predetermined load, and arranged to align the up-down direction within a column-shaped member; a control device arranged above the battery packs and controlling the battery packs; an immersion sensor provided in each of the plurality of battery packs;and a notification unit providing notification of information regarding the immersion outward, wherein the control means includes a communication unit receiving information indicating immersion from immersion sensors in each battery pack, a determining unit determining the degree of immersion based on which of the immersion sensors has transmitted the received information indicating immersion, and a control unit controlling the notification unit to provide notification of information of the degree of immersion indicating the degree of immersion determined by the determining unit outward.; [Beneficial Effects of Invention] According to the present invention, it is possible to provide an electrical storage device that can provide notification of immersion information to the outside. Short Description of Image Figure 1 is a schematic diagram of a solar street light configuration according to an example of the present invention, wherein (a) is a front view and (b) is a left side view. Figure 2 is a schematic configuration diagram of a solar street light battery pack according to the example of the present invention. Figure 3 is a block diagram illustrating the configuration of a solar street light control device according to an example of the present invention. Figure 4 is a block diagram illustrating the electrical connection outline of a solar street light according to the example of the present invention. Complete Description of the Invention An electrical storage device according to an embodiment of the present invention is characterized by including: a plurality of battery pack covers capable of supplying electricity to a predetermined load, and arranged parallel to the up-down direction within a columnar member; a control device arranged above the battery packs and controlling the battery packs; immersion sensors provided in each of the plurality of battery packs; and a notification unit providing notification of information regarding immersion outward, wherein the control device includes a communication unit receiving information indicating immersion from immersion sensors in each battery pack, a determining unit determining the degree of immersion based on which of the immersion sensors has transmitted the received information indicating immersion, and a control unit controlling the notification unit to provide notification of information of immersion degree indicating the degree of immersion determined by the determining unit outward.With this configuration, the electrical storage device according to an embodiment of the present invention can provide notification of external immersion information. [Embodiment] Next, the electrical storage device according to the example of the present invention will be explained with reference to the drawings. As illustrated in Figure 1, this example is explained using an electrical storage device used for an outdoor-mounted solar street light as an example. (Solar street light configuration) The solar street light (1) as a street light includes a column member (2), a solar panel (3), a lighting device (4) as a predetermined load, a number of battery packs (5), and a control device (6). The solar street light (1) is installed in the ground (G). Next, based on the column section (2), the illumination device (4) side is defined as the front, the opposite side is defined as the back, when looking at the front side from the back side, the left side is defined as the left, the right side is defined as the right, and the top side is defined as the top. From the side surface of the column section (2), the side surface where the illumination device (4) is installed is the front side of the solar street light (1). The columnar member (2) is formed from a square column, and is formed in a hollow form having a space inside. The columnar member (2) can also adopt a shape other than a square column, such as a prism or a cylinder. As will be explained later, a number of battery packs (5) capable of supplying electricity to the illumination device (4) and the control device (6) are installed inside the column (2). The control device (6) is positioned above a plurality of battery packs (5) within the columnar component (2). A first opening (21) and a second opening (22) located above the first opening (21) are formed on the side surface (2a) on the front side of the columnar component (2). The first opening (21) is provided at the mounting position of the multiple battery pack (5). The first opening (21) is used when performing work such as replacing the battery pack (5) and performing maintenance, for example, and is closed by a cover (21a) when work is not being performed. A second opening (22) is provided at the mounting position of the control device (6). The second opening (22) is used when operating the control device (6) or performing maintenance work, for example, and is closed by a cover (22a) when operation and work are not being carried out. In this example, the mounting area of ​​a plurality of battery packs (5) in the columnar component (2) is longer than the mounting area of ​​the control device (6) in the height direction of the columnar component (2), and therefore the first opening (21) is longer than the second opening (22) in the height direction. The drain pipe (25) embedded under the ground (G) is connected to the bottom of the column component (2). The drain pipe (25) is a pipe for draining moisture that collects at the bottom of the column component (2) down to the ground as waste water. The solar panel (3) is mounted on (23) the top of the column (2). The solar panel (3) is made up of photovoltaic modules that generate electricity using optical energy from the sun, and is adjusted to the installation location of the solar street light (1), so that the solar panel (3) is oriented to receive the maximum amount of sunlight throughout the year. The solar panel (3) is connected to a battery pack (5) and a controller (6) to supply electricity to it. The illumination device (4) is positioned at the top of the side surface (2a) on the front side of the columnar component (2), and shines light downwards from the top of the columnar component (2). A battery pack (5) is a used vehicle battery pack that has been installed in a vehicle. In this example, in order to reuse a battery pack with a small capacity used in a hybrid vehicle, a plurality of battery packs (5) are combined to increase the usable capacity of the reused battery pack (5), the performance of which varies due to different capacities and the degree of decrease in internal resistance and the like depending on the usage history. Since the remaining service life differs among the many combined battery packs (5), there is a high probability that the battery pack (5) will need to be replaced during use. In this example, by arranging a plurality of battery packs (5) within the columnar component (2) as described above, even when anomalies occur in some of the battery packs (5), operation as a street lamp can be guaranteed by the remaining battery packs (5). The battery pack (5) is formed in the form of a rectangular parallelepiped where the sides in the vertical direction are shorter than the sides in the horizontal direction when placed in the transverse direction. Placed in the transverse direction refers to how the battery (5) is placed when installed on the vehicle, and how the battery is placed so that its thickness is minimized. In this example, the battery packs (5) are arranged in such a way as to be positioned in a vertical direction within the columnar portion (2). In addition, in this example, a plurality of vertically positioned battery packs (5) are arranged to be aligned in an up-down direction within the columnar portion (2). A number of battery packs (5) are arranged in an ascending and descending direction within a columnar section (2) forming a battery pack group. In this example, five battery packs (5) are arranged in an ascending and descending direction forming one battery pack group. The number of battery packs (5) included in a battery pack group is not specified, and is not limited to five. In addition, in this example, two rows of battery pack groups are provided within the columnar component (2). Of the two rows of battery pack groups, one is referred to as battery pack group (5A), and the other is referred to as battery pack group (5B). The number of rows of battery pack groups provided within the columnar component (2) is not limited to two, and may be one, or three or more, for example. Battery packs (5) of the same battery pack group are connected to the same cable. Specifically, five battery packs (5) included in the battery pack group (5A) are connected to the cable (50A), and five battery packs (5) included in the battery pack group (5B) are connected to the cable (50B). The wiring (50A) and wiring (50B) are routed in an up-down direction within the column component (2). The positive terminal (60) and the power supply terminal (63) described later of each battery pack (5), solar panel (3), illumination device (4), control device (6), and the like of the corresponding battery pack group are connected to the respective cable (50A) and cable (50B). The battery pack group (5A) and the battery pack group (5B) form different battery pack group systems, and can function independently. For this reason, even if a problem occurs in one system, the battery pack can be operated by the other system that is not experiencing problems. The controller (6) is connected to the battery management system (BMS) (55) (see Figure 2) described later in the battery pack (5), and controls a plurality of battery packs (5) via the BMS (55). The controller (6) exchanges information with the BMS (55) via communication. The control device (6) is formed from a computer unit including a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), input ports, and output ports. The program to cause the computer unit to function as the control device (6) is stored, along with various constants and the like, in the ROM of the computer unit. That is, the CPU executes the program stored in the ROM by using RAM as a working area causing the computer unit to function as the control device (6) of this example. Various sensors (7) (see Figure 4) are connected to the control device (6). For example, sensors capable of detecting changes in the external environment such as illumination sensors are connected to the control device (6). The control device (6) may include a timer that regulates the lighting duration and the lighting time. The configuration of the control device (6) will be described in detail later. (Battery pack electrical configuration) Next, the electrical configuration of the battery pack (5) of this example will be explained with reference to Figure 2. As illustrated in Figure 2, the battery pack (5) includes a battery (53), a relay (54), a BMS (55), and a submersion sensor (56). The battery (53), the relay (54), the BMS (55), and the submersion sensor (56) are provided inside the battery pack (5). The battery (53) is formed from a secondary battery that can be charged and discharged like a lithium ion battery. The battery (53) has a positive electrode (53a) and a negative electrode (53b). The positive electrode (53a) of the battery (53) is connected to the positive terminal (60) via the relay (54) so ​​that it is electrically conductive. The positive terminal (60) is the terminal that outputs the battery voltage (53) to the outside of the battery pack (5), and is exposed to the outside of the battery pack (5). The negative electrode (53b) of the battery (53) is connected to the battery pack case (5) via the ground terminal (61). The relay (54) is a switch provided between the positive electrode (53a) of the battery (53) and the positive terminal (60), and is capable of switching between a connected state in which the positive electrode (53a) of the battery (53) and the positive terminal (60) are connected and a disconnected state in which both are disconnected. The relay (54) is switched to the disconnected state when immersion of the battery pack (5) is detected by the immersion sensor (56). The BMS (55) monitors and manages the state of the battery (53) such as the voltage value and state of charge (SOC) of the battery (53). The BMS (55) calculates the SOC based on the charging and discharging current of the battery (53). The BMS (55) controls the switching between the connected state and the disconnected state of the relay (54). The BMS (55) is connected to the controller (6) via the communication terminal (62) provided in the battery pack (5). The BMS (55) is connected to the power supply via the power supply terminal (63) and the power supply GND terminal (64) provided in the battery pack (5). In this example, the battery (53) and the solar panel (3) are used as the power supply. The immersion sensor (56) is a sensor that detects the immersion of the battery pack (5). Various immersion sensors such as sensors that detect immersion by sensing hydraulic pressure of a predetermined pressure or greater indicated immersion, sensors that detect immersion when the positive and negative terminals are immersed in water and there is continuity between the terminals, or the like can be used as the immersion sensor (56). Here, the battery pack (5) is mounted in a vertical direction within the column section (2) to be oriented so that the positive terminal (60) is located above the immersion sensor (56). Consequently, the positive terminal (60) is located above the immersion sensor (56). (Control tool configuration) Next, the configuration of the control device (6) of this example will be explained with reference to Figure 3. As illustrated in Figure 3, the controller (6) functions as a communication unit (71) that receives immersion indication information from the immersion sensors (56) in each battery pack (5). The controller (6) functions as a determining unit (72) that determines the degree of immersion on the basis of which of the immersion sensors (56) in the battery pack (5) has transmitted the received information indicating immersion. Here, the ROM of the controller (6) stores, for each battery pack (5), the height from the ground (G) to the installation position of the battery pack (5) as height information. The controller (6) can identify the battery pack (5) including the immersion sensor (56) from which the information indicating immersion has been received, and determine the level of immersion by referring to the height information of the identified battery pack (5). That is, the controller (6) can determine to what depth (how many meters) the solar street light (1) is submerged in water. The control device (6) functions as a control unit (73) that controls the notification unit (80) described later to provide notification of immersion degree information indicating the immersion degree determined by the determining unit (72) to the outside. The immersion degree information is information indicating the immersion height of the solar street light (1) at its installation location. A notification unit (80) that provides notification information regarding the outward immersion is connected to a control device (6). The notification unit (80) is formed of an analog, digital, or other type indicator, and is provided on the outer surface of the column member (2). With this configuration, the control device (6) can display the immersion height of the solar street light (1) at its installation location on the indicator. The outer surface of the columnar component (2) on which the notification unit (80) is provided is preferably a side surface (2a) on the front side of the columnar component (2), for example. In this case, in order for the notification unit (80) to provide notification to a wider area, the notification unit (80) is expected to be provided at the top of the side surface (2a) on the front side of the columnar component (2). (Solar street light electrical connection) Next, the electrical connection of the solar street light (1) of this example will be explained with reference to Figure 4. As illustrated in Figure 4, one to n (n = 5 in this example) battery packs (5) are provided in the solar street light (1) according to this example. In this example, in order to distinguish among the plurality of battery packs (5), the plurality of battery packs (5) are denoted by battery packs (5)(1) to (5)(n). When referring to a single battery pack without specifying which battery packs are (5)(1) to (5)(n), the battery pack is simply referred to as battery pack (5). In Figure 4, the battery pack (5) of the battery pack group (5A) connected to the cable (50A) is illustrated as an example of battery packs (5)(1) to (5)(n). Therefore, the cable (50B) and the battery pack group (5B) are omitted from Figure 4. Battery packs (5)(1) to (5)(n) are connected in parallel with each other with respect to cables (50A). In this example, to identify which of the battery packs (5)(1) to (5)(n) the battery (53), relay (54), and BMS (55) belong to, the battery (53), relay (54), and BMS (55) corresponding to the battery packs (5)(1) to (5)(n) are denoted by battery (53)(1) to (53)(n), relay (54)(1) to (54)(n), and BMS (55)(1) to (55)(n). Regarding batteries (53)(1) to (53)(n), relays (54)(1) to (54)(n), and BMS (55)(1) to (55)(n), when referring to a single battery, relay, and BMS without specifying which of the battery packs (5)(1) to (5)(n) are the components, the components are simply referred to as battery (53), relay (54), and BMS (55). A first switch (8) capable of switching between an ON state where the BMS (55) and the cable (50A) are connected and an OFF state where both are disconnected is provided between the BMS (55) and the cable (50A). At least one first switch (8) is provided for each BMS (55). While this example describes an instance where one first switch (8) is provided for each BMS (55), two or more first switches (8) may be provided for each BMS (55). In this example, to identify which BMS (55)(1) to (55)(n) the first switch (8) belongs to, the first switch (8) corresponding to BMS (55)(1) to 55(n) is denoted by the first switch (8) (1) to (8)(n). Regarding the first switch (8)(1) to (8)(n), when referring to a single switch without specifying which BMS from (55)(1) to (55)(n) the switch belongs to, the switch is simply referred to as the first switch (8). The control device (6) controls the switching between the ON state and the OFF state of the first switch (8). The second switch (9) is connected to one end of the cable (50A). The second switch (9) is a switch provided between the cable (50A), and the solar panel (3) and the illumination device (4), and is capable of switching between an ON state where the cable (50A) and the solar panel (3) or illumination device (4) are connected and an OFF state where both are disconnected. That is, the second switch (9) is capable of switching between the ON state which is the ON state of the power generator connecting the cable (50A) and the solar panel (3) or the ON state connecting the cable (50A) and the illumination device (4), and the OFF state not connecting the cable (50A) with either the solar panel (3) and the illumination device (4). The control device (6) controls the switching between the power generation-ON state or the discharge-ON state and the OFF state of the second switch (9). In the case where the power of the control device (6) is not turned on, such as at the time of the initial start-up of the solar street lamp (1), from the point of view of ensuring electricity to start the solar street lamp (1), it is recommended that the second switch (9) be switched to the power generation-ON state. The controller (6) is connected to the cable (50A), and receives power supply from at least one solar panel (3) and battery packs (5)(1) to (5)(n) via the cable (50A). The controller (6) controls the switching between the ON state and the OFF state of the first switch (8) and the second switch (9). In this example, the battery packs (5) are arranged from top to bottom in the order of battery packs (5)(1) to (5)(n) within the columnar component (2). The first switch (8) is arranged above the relay (54). (Solar street light operation) Next, we will explain the operation of the solar street light (1) when the installation location of the solar street light (1) is flooded. In the solar street light (1) configured as described above, when the installation location of the solar street light (1) is flooded, the following operations are performed. For example, when the immersion sensor (56) of the battery pack (5)(n) detects immersion in a state where the battery pack (5)(n) is supplying power, the first switch (8)(n1) of the battery pack (5)(n-1) set directly above the battery (5)(n) is switched to the ON state. After the first switch (8)(n-1) is switched to the ON state, the relay (54)(n-1) is switched to the connected state. After that, the relay (54)(n) of the battery pack (5)(n) is switched to the disconnected state. When relay (54) (n) is switched to the disconnected state, the first switch (8)(n) is switched to the OFF state. By operating the solar street light (1) in the above procedure, it is possible to prevent interruption of the power supply from the battery (5). In addition, even when some of the batteries (5) are submerged in water, the remaining batteries (5) can be used to continue lighting with the illumination tool (4). The control device (6) is mounted above the topmost battery pack (5) (1), and can therefore maintain the power supply from the battery pack (5) and continue lighting with the lighting device (4) until all the battery packs (5) are submerged in water. In addition, as explained above, when the installation location of the solar street light (1) is flooded, the immersion sensors (56) in the battery packs (5) are activated sequentially from the bottom battery pack (5) to the top battery pack (5) installed in the columnar component (2). In this case, as explained above, since the controller (6) is installed above the battery packs (5), the controller (6) can operate as long as the controller (6) is not immersed in water even if all the battery packs (5) are immersed in water. Therefore, the controller (6) can know whether all the battery packs (5) are immersed in water or not. On the basis of the height information of the battery pack (5) from which the information indicating immersion is received, the controller (6) determines to what height (how many meters) the solar street light (1) is immersed in water, and provides notification of the immersion level information to the outside via the notification unit (80). When receiving information indicating immersion from the immersion sensor (56) of a particular battery pack (5) among a plurality of battery packs (5) belonging to the same battery pack group, if information indicating immersion is not received from the immersion sensor (56) of the battery pack (5) lower than that of the battery pack (5) that detected the immersion, the controller (6) determines that an anomaly has occurred in the immersion sensor (56) that has sent the information indicating immersion. Note that the controller (6) can determine whether the immersion sensor (56) has transmitted information indicating normal or abnormal immersion by a majority rule regarding the receiving state of the immersion sensor (56) including the immersion sensor (56) of the battery pack (5) being lower than the battery pack (5) that has detected immersion. When receiving information indicating immersion from an immersion sensor (56) of a particular battery pack (5) belonging to one group of battery packs among a plurality of groups of battery packs, if no information indicating immersion has been received from a battery pack (5) belonging to another group of battery packs at the same height as the battery pack (5) that has detected immersion, the controller (6) determines that an anomaly has occurred in the immersion sensor (56) that has transmitted the information indicating immersion. Note that the controller (6) may determine whether the immersion sensor (56) has transmitted information indicating normal or abnormal immersion by majority rule regarding the receiving states of the immersion sensors (56) including the immersion sensors (56) of the battery packs (5) at the same height as the battery packs (5) that have detected immersion but belong to another group of battery packs. As described, in an electric storage device according to this example, a control device (6) determines a degree of immersion based on which an immersion sensor (56) has transmitted information indicating immersion, and controls a notification unit (80) to provide notification of immersion degree information indicating the determined degree of immersion to the outside. Thus, the electric storage device can provide notification of immersion information to the outside. In the electric storage device according to this example, since the notification unit (80) is an indicator provided on the side surface (2a) on the front side of the column component (2), it is possible to provide notification of the degree of immersion information to the outside, such as to the periphery of the solar street lamp (1), by the solar street lamp (1) alone. Therefore, it is possible to warn the driver of a vehicle located at the periphery of the solar street lamp (1) not to enter the area near the installation location of the solar street lamp (1) that is flooded. Note that while the notification unit (80) is formed from an indicator in this example, the invention is not limited thereto, and the notification unit (80) may be formed from an illumination device (4). In this case, it is possible to notify the driver of a vehicle that is in the flooded state of the solar street light (1) by the flashing pattern or flashing cycle of the illumination device (4). For example, the control device (6) shortens the flashing cycle when multiple battery packs (5) detect flooding. Alternatively, in the event of flooding, the illumination device (4) may be illuminated with a color other than the illumination color used for lighting at times other than flooding. In addition, a red light, for example, may be provided in the illumination device (4), and the red light may be illuminated to provide notification of the flooding state.By forming a notification unit (80) by the illumination device (4) as described above, the immersion degree information can be notified using the illumination device (4), so that a separate indicator is not required, and the configuration can be simplified. Alternatively, a notification unit (80) may be formed from a communication device that transmits the immersion level information to the outside. In this case, it is possible to notify facilities that need to monitor flood conditions from a location remote from the solar street light (1) about the flood conditions around the installation location of the solar street light (1), and immediately report the flood conditions to the local government or the like. The local government or the like can immediately take necessary measures against the flood. Alternatively, the notification unit (80) may have, in addition to the indicator, the function of a communication device that transmits flood level information to the outside. In this case, it is also possible to provide flood notification to areas other than the periphery of the solar street light (1). While this example describes a case where the electricity storage device according to the present invention is applied to a solar street lamp (1) using a solar panel (3) as a power generator, the present invention is not limited thereto. For example, the electricity storage device according to the present invention can be applied to a street lamp including an aerogenerator as a power generator. While examples of the present invention have been disclosed, modifications may be made without departing from the scope of the present invention by persons skilled in the art, as a matter of course. All such modifications and their equivalents are intended to be incorporated in the following claims. [List of Reference Marks] (1) solar street light (street light) (2 columnar members (2a) side surface (outer surface) (3) solar panel (4) lighting device (predetermined load) (5) battery pack (5A), battery pack group (5B) (6) control device (21) first opening opening (22) second (23) top (25) drain pipe Cable (50A),(50B) (53) battery positive electrode(53a) negative electrode(53b) (54) relay (55) BM (56) immersion sensor (60) positive terminal (61) ground terminal (71) communication unit (72) determination unit (73) control unit (80) ground notification unit (G)

Claims

1. An electrical storage device comprising: a plurality of battery packs (5) capable of supplying electricity to a predetermined load (4), and mounted to align the up-down direction within the column member (2); a control device (6) arranged above the battery packs (5) and controlling the battery packs (5); a submersion sensor (56) provided in each of the plurality of battery packs (5);and a notification unit (80) that provides notification of information regarding immersion to the outside, the electric storage device is characterized in that it includes a control device (6) comprising a communication unit (71) that receives information indicating immersion from immersion sensors (56) in each battery pack (5), a determination unit (72) that determines the degree of immersion based on which of the immersion sensors (56) transmits the received information indicating immersion, and a control unit (73) that controls the notification unit (80) to provide notification of information indicating the degree of immersion determined by the determination unit (72) to the outside.; 2. An electrical storage device as claimed in claim 1, wherein the notification unit (80) is an indicator provided on the outer surface (2a) of the columnar component (2).

3. An electric storage device as claimed in claim 2, wherein the electric storage device is used for a street lamp (1) wherein the predetermined load (4) is an illumination device (4), and an indicator is formed from the illumination device (4).

4. An electrical storage device as claimed in claim 1, wherein the notification unit (80) is formed from a communication device that transmits the immersion degree information to the outside.

5. An electrical storage device as claimed in claim 2 or 3, wherein the notification unit (80), in addition to the indicator, has the function of a communication device that transmits information of the degree of immersion to the outside.

6. An electrical storage device as claimed in any one of claims 1 to 5, wherein the battery pack (5) is a battery pack on a reused vehicle.