Power bank module, power bank and method for operating a power bank module
Patent Information
- Application Number
- EP2023834074
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-28
- Filing Date
- 2023-12-18
- Publication Date
- 2025-11-05
AI Technical Summary
The increasing energy requirements of helmet accessories, such as helmet lights and headsets, lead to a heavy and impractical energy storage unit that is difficult to wear on safety helmets, necessitating frequent deactivation and replacement, which disrupts the energy supply to electrical consumers.
A power bank module with a PCB that manages multiple battery ports and a control controller to establish isolated circuits for each battery pack, allowing for simultaneous connection of multiple energy storage devices and electrical consumers, enabling efficient energy distribution and communication between components, while cyclically switching between battery packs to maintain balanced charge states.
This solution allows for a compact and efficient energy supply to helmet accessories, preventing interruptions in power and maintaining balanced battery states, simplifying voltage regulation and charging control, and enabling continuous operation without the need for frequent battery changes.
Smart Images
Figure 1.1
Abstract
Description
[0001] Power bank module, power bank and method for operating a power bank module
[0002] The present invention relates to a power bank module, a power bank and a method for operating a power bank module.
[0003] For many jobs, especially in forestry, wearing a protective helmet is required. A corresponding protective helmet comprising a helmet shell with an interior liner comprising a head-contacting assembly, which in turn consists of at least a carrying basket, a headband, and a neckband, and having means for attaching this assembly to the helmet shell, is known, for example, from document DE 87 14490 U1.
[0004] This well-known safety helmet represents a basic helmet that can be adapted to different tasks in different operating conditions by changing attachments. The safety helmet consists of a helmet shell and a minimum of internal fittings. The internal fittings include a cross-strap with which the helmet is worn on the head and which ensures an impact-absorbing distance between the head and the helmet shell. The safety helmet has a projection on its outer circumference that encircles the sides and rear of the helmet. At the bottom, this projection contains four recesses for attaching the cross-strap and further recesses for attaching additional attachments. The basic version of the helmet can be used as a simple universal helmet without any attachments. The attachments can be added or removed as needed.
[0005] Helmet accessories that are useful to attach to a safety helmet include a helmet light, which, similar to a headlamp, provides additional illumination of the work area of the helmet wearer. Such additional illumination of the work area or other areas can be useful not only during dawn and dusk and after dark, but also in areas shielded from daylight, such as twilight under a closed tree canopy. To operate the helmet light, a suitable energy storage device is required, for example in the form of at least one rechargeable battery or a battery pack. Other helmet accessories may also rely on an electrical power supply, such as a headset with a radio receiver or Bluetooth headphones.
[0006] However, the disadvantage is that the energy requirement increases with the number of electrical devices on the helmet and also increases proportionally with the duration of use, i.e., the operating time of the electrical devices. Therefore, due to the limited energy density of batteries or battery packs, the weight of the large energy storage device required may make it impossible or at least impractical to wear it directly on the helmet. At the same time, changing a smaller energy storage device on the helmet is disadvantageous, especially given the temporary deactivation of the electrical devices required during the change.
[0007] The object of the invention is to at least alleviate the above-mentioned problem.
[0008] This problem is solved with the help of the subject matter having the features of the independent claims. Useful embodiments and further developments arise from the dependent claims.
[0009] The power bank module according to the invention comprises a PCB with a control controller arranged thereon, a plurality of battery ports arranged on the PCB, which are configured to establish a functional connection between a number of battery packs that can be connected to the plurality of battery ports, and the power bank module, at least one supply connection arranged on the PCB, to which a consumer can be connected, wherein the supply connection is configured to establish a functional connection between the connected consumer and the power bank module, a charging connection arranged on the PCB, to which an energy source can be connected, wherein the charging connection is configured to establish a functional connection between the energy source and the power bank module, and wherein the control controller is configured to open and close circuits between the plurality of battery ports,the at least one supply connection and the charging connection such that a closed circuit comprising the at least one supply connection always comprises only one battery port of the plurality of battery ports, while all others of the plurality of battery ports are electrically separated from the supply connection. In this way, a plurality of energy storage devices connected to the battery ports of the power bank module can be mechanically connected simultaneously to the power bank module arranged on the power bank module, to which, in turn, electrical consumers can be connected. A mechanical replacement of an individual monolithic energy storage device, which leads to an interruption of the energy supply to a connected electrical consumer, can therefore be avoided. Electrical separation is to be understood as meaning that a current flow, in particular a supply or charging current,is prevented. The existing connections on the power bank module, i.e., the supply connection, the charging connection, and the battery ports, can, in addition to such an electrically separable current flow, also support or enable electrical communication between the connected / existing components, i.e., the electrical consumer, the battery packs connected to the battery ports, the possibly connected energy source, and the power bank module itself. The electrical connections provided via the power bank module between the existing / connected components can thus also exchange information with each other, for example, type information or current status or operating information.which may be relevant for the operation of the system including the power bank module. The power bank module can therefore act as a data bus or hub for the connected components and actively participate in the ongoing communication or even control it.
[0010] Usefully, the control controller can be further configured to control the opening and closing of circuits between the plurality of battery ports, the supply port, and the charging port such that the battery port encompassed by the closed circuit alternates cyclically. This measure allows the battery packs connected to the various battery ports to be loaded essentially evenly, so that their charge level, temperature, etc., remain similar to one another during use of the power bank.
[0011] Furthermore, the cyclical switching between the battery ports can be time-controlled or based on another measurable parameter. This allows the states of the various battery packs connected to the battery ports to be even better aligned during operation. For example, the age, maximum battery capacity, current battery capacity, or similar factors of the various battery packs can be taken into account.
[0012] Advantageously, it can be provided that the power bank module comprises at least two supply connections, and wherein the control controller is configured to control the opening and closing of circuits between the plurality of battery ports, the at least two supply connections, and the charging connection such that two separate closed circuits, each comprising one of the at least two supply connections, always comprise only one battery port of the plurality of battery ports, while all others of the plurality of battery ports are electrically separated from the respective supply connection. In particular, it can be provided that the two battery ports in the two separate closed circuits are different. By dividing the circuits into separate circuits, each consumer connected to a supply connection can always be powered from a single battery pack.This simplifies the voltage regulation required for the operation of the power bank module, as there is no need to consider either a parallel or series connection of the battery packs, which may have different performance data.
[0013] It can also be provided that the control controller is further configured to control the opening and closing of circuits between the plurality of battery ports, the supply connection, and the charging connection such that the battery port encompassed by the two closed circuits alternates cyclically. This allows charging of the connected battery packs while the power bank module is operating to supply one or more connected consumers, while ensuring that the operating state of the connected battery packs is maintained at a similar level.
[0014] Usefully, the control controller can be further configured to control the opening and closing of circuits between the plurality of battery ports, the supply connection, and the charging connection such that the charging connection and the at least one supply connection are always electrically isolated from one another, and such that a closed circuit including the charging connection always includes only one battery port of the plurality of battery ports, while all other battery ports of the plurality of battery ports are electrically isolated from the charging connection. This prevents a charging current from "looping through" to a connected load. Furthermore, charging control of the individual connected battery packs is simplified, since no parallel or serial charging of multiple connected battery packs occurs.To maintain the operating states of the connected battery packs essentially the same, cyclic switching between the battery packs can be provided. The other parameters mentioned above in connection with supplying an electrical load can be used to control the switching.
[0015] Advantageously, the plurality of battery ports arranged on the PCB can each comprise a first magnet and a second magnet. The magnets can hold the battery packs in their connected position at the respective battery port. The electrical contacts themselves can be realized via individual spring-loaded pins, which, under load, are telescopically pushed together in their extension direction and thereby press against flat or smooth corresponding electrical contact surfaces ("pogo pins").
[0016] Also described is a power bank comprising such a power bank module and at least two battery packs that are functionally connected to the power bank module. The battery packs themselves can also comprise two magnets that interact with magnets possibly provided on the battery ports to hold the battery packs in their connected position, thereby providing an anti-twist lock.
[0017] The described power bank module can thus be part of a power bank that, in addition to the power bank module, includes at least two battery packs connected to the battery ports. The power bank, in turn, can be part of a battery system in which the power bank is connected to an electrical load in the form of another battery pack. The battery system, in turn, can be part of a helmet light system, with the helmet light of the helmet light system being powered by electrical energy from the battery pack, which is connected to the power bank as an electrical load.
[0018] The method according to the invention for operating a power bank module provides that a control controller controls the opening and closing of circuits between the plurality of battery ports, the at least one supply connection, and the charging connection such that a closed circuit comprising the at least one supply connection always encompasses only one of the plurality of battery ports, while all other battery ports of the plurality of battery ports are electrically isolated from the at least one supply connection. In this way, the advantages and special features of the helmet light according to the invention can also be implemented within the framework of a method.
[0019] Usefully, it can be provided that the power bank module comprises at least two supply connections, and wherein, by the control controller, an opening and closing of circuits between the plurality of battery ports, the at least two supply connections and the charging connection is controlled such that two mutually separate closed circuits, each comprising a supply connection of the at least two supply connections, always comprise only one battery port of the plurality of battery ports, while all others of the plurality of battery ports are electrically separated from the respective supply connection of the at least two supply connections.
[0020] Advantageously, it can be provided that, by the control controller, the opening and closing of circuits between the plurality of battery ports, the at least one supply connection and the charging connection is controlled such that the charging connection and the at least one supply connection are always electrically separated from one another, and that a closed circuit comprising the at least one charging connection always comprises only one battery port of the plurality of battery ports, while all others of the plurality of battery ports are electrically separated from the charging connection.
[0021] They show:
[0022] Figure 1 is a schematic representation of an exemplary power bank;
[0023] Figure 2 is a plan view of a stylized exemplary PCB;
[0024] Figure 3 is a three-dimensional view of an exemplary battery pack; and
[0025] Figure 4 shows a three-dimensional representation of an example helmet light.
[0026] In the following designations, like reference numerals designate like or functionally similar elements. Figure 1 shows a schematic representation of an exemplary power bank 10. The power bank 10 shown essentially consists of a power bank module 12, on which a first battery port 14, a second battery port 14', and a third battery port 14" are arranged. It is optionally possible for additional battery ports to be arranged on the power bank module 12. A supply connection 16 and a charging connection 18 are also provided on the power bank module 12. Figure 1 shows a charging cable 20 plugged into the charging connection 18, via which electrical energy can be supplied to the power bank 10 from an external source. This supplied electrical energy can be stored by the power bank 10.For this purpose, in Figure 1, a first additional battery pack 100' is plugged into the first battery port 14, a second additional battery pack 100" is plugged into the second battery port 14', and a third additional battery pack 100'" is plugged into the third battery port 14". A control logic of the power bank module 12 can suitably store the electrical energy supplied via the charging cable 20 in the additional battery packs 100', 100" and 100'", wherein the additional battery packs 100', 100", 100'" are charged during this process. The charging of the additional battery packs 100', 100", 100'" can be designed such that the individual additional battery packs 100', 100", 100'" are charged alternately, so that the respective charge states of the individual additional battery packs 100', 100", 100'" should be kept at a similar level.
[0027] The control logic of the power bank module 12 can thus be configured such that only one battery pack of the additional battery packs 100', 100", 100'" is charged at a time, wherein the control logic of the power bank module 12 can simultaneously ensure, by cyclically switching between the additional battery packs 100', 100" and 100'", that the respective charge states of the additional battery packs 100', 100", 100'" remain or are maintained substantially the same.
[0028] The further battery packs 100', 100", 100'" can in particular be designed identically, which consequently means that the first battery port 14, the second battery port 14' and the third battery port 14" are also designed identically.
[0029] The power bank module 12 also features the aforementioned supply connection 16, to which a connecting charging cable 22 is plugged in Figure 1. This charging cable, in turn, terminates in a charging plug 24 with contact pins 42, which are only indicated in Figure 1. Starting from the supply connection 16, an electrical load, not shown in Figure 1, can be coupled to the power bank 10 via the connecting charging cable 22 with the charging plug 24 and the contact pins 42. Optionally, the power bank module 12 may have more than one supply connection 16.
[0030] The control logic of the power bank module 12 can be designed such that an electrical consumer connected to the power bank 10 at the supply connection 16 via the connecting charging cable 22 and the charging plug 24 is electrically connected at any given time to only one of the additional battery packs 100', 100", 100'". Accordingly, electrical energy is drawn from only one of the additional battery packs 100', 100", 100'" at a time to supply the connected electrical consumer.In order to keep the charge level of the additional battery packs 100', 100", 100'", essentially the same as when charging the additional battery packs 100', 100", 100'", in this context it can be provided that the control logic of the power bank module 12 switches cyclically between the additional battery packs 100', 100" and 100'", so that essentially the same amounts of energy are alternately drawn from each of the additional battery packs 100', 100", 100'" during a discharge process and supplied to a connected electrical consumer.
[0031] It is conceivable that during a discharging process of one of the further battery packs 100', 100", 100'", another of the further battery packs 100', 100", 100'" is charged at the same time. It is also possible for the power bank module 12 to be connected to another power bank via the charging port 18 and the charging cable 20 arranged thereon, wherein the power bank 10 can then be regarded as an electrical consumer for the other power bank (not shown). It is also possible for the charging cable 20 to terminate in a commercially available charger which is supplied with electrical energy, for example, from a public power grid, and to supply this energy to the power bank 10 in a suitable manner.
[0032] The cyclical switching between the additional battery packs 100', 100", 100'" during the charging / discharging processes can, for example, be time-controlled. It is conceivable, for example, that a switch during a charging / discharging process is carried out by the control logic at least every 15 minutes, preferably after 10 minutes, particularly preferably after 5 minutes. The exact time period after which a switch to the next additional battery pack 100', 100", 100'" should take place can, for example, be stored in the respective additional battery pack 100', 100", 100'" as a parameter readable by the power bank module. In addition to a simple cyclic time control for switching between the additional battery packs 100', 100", 100'", a control based on another measurable parameter is also possible, for example a temperature of the additional battery packs 100', 100", 100'", to limit a temperature difference between the additional battery packs 100', 100", 100'", the amount of energy drawn, etc.
[0033] If the power bank 10 has multiple supply connections 16, the control logic of the power bank module 12 can be designed such that each of the additional battery packs 100', 100", 100'" is electrically connected to exactly one of the supply connections, so that virtually every electrical consumer connected to the power bank 10 via one of the supply connections 16 is electrically connected to its own additional battery pack 100', 100", 100'" and is supplied with electrical energy by it. Here, too, a cyclical switching between the existing additional battery packs 100', 100", 100'" can be provided. Electrically connecting only one additional battery pack 100', 100", 100'" to the charging connection 18 or the supply connection 16 simplifies voltage regulation, since neither a parallel connection nor a series connection of the existing additional battery packs 100', 100", 100'" needs to be taken into account.
[0034] The control logic of the power bank module 12 can enable communication between the power bank 10 and all components connected to the power bank module 10, for example, via a UART protocol. Thus, the electrical load connected to the supply connection 16 can communicate both with the control logic of the power bank module 12 and with the additional battery packs 100', 100", 100'" connected to it. The same applies to the control logic of the power bank module 12 and to a charger or another power bank that may be connected to the power bank 10 via the charging cable 20. For example, it is conceivable that a mobile phone is connected to the power bank 10 via the charging connection 18, whereby the provided communication between the control logic of the power bank module 12 and the connected mobile phone can enable the power bank 10 to use various functions of the mobile phone.For example, the mobile phone can be used to locate the Powerbank 10 via GPS. It is also possible to send an emergency call via the mobile phone or to control devices connected to the Powerbank via the mobile phone.
[0035] The supply port 16 and the charging port 18 can be pin-compatible, so that it is irrelevant for the power bank 10 or the power bank module 12 where an electrical consumer is connected or where a charger is connected. Whether the respective port acts as a supply port 16 or a charging port 18 can be determined, for example, using the established communication between the connected device and the control logic of the power bank module 12.
[0036] Figure 2 shows a simplified top view of an exemplary PCB 32. The illustrated PCB 32 comprises the battery ports 14, 14' and 14", already known from Figure 1, the supply connection 16 and the charging connection 18. In addition to the supply connection 16, further supply connections 16', 16" are shown. As already explained in connection with Figure 1, the connections 16, 16', 16", 18 can be pin-compatible. For example, it is possible for the connections 16, 16', 16", 18 to each be designed as USB-C connections. The provision of other connection types, for example jack plugs, is of course also possible, as is the different design between the supply connections 16, 16', 16" and the charging connection 18. The PCB 32 of the power bank module 12 carries, in addition to the connections 16, 16', 16" and 18, the battery ports 14, 14', 14", which are also already known from Figure 1.These are shown in Figure 2 in a top view, so that each of the additional battery packs 100', 100", 100'" would be inserted (from above into the plane of the page). The additional battery packs 100', 100", 100'" are pushed into a respective frame 40, 40', 40" until they finally touch the base of the respective battery port 14, 14', 14". The respective connection contacts 38 will then form electrical connections with the corresponding electrical contacts of the additional battery packs 100', 100", 100'". On both sides of the connection contacts in the respective battery ports 14, 14', 14", first and second magnets 36, 36' are shown as examples in Figure 2, which can hold inserted additional battery packs 100', 100", 100'" in the inserted connection position.In order to provide anti-twist protection when inserting the additional battery packs 100', 100", 100'", the additional battery packs 100', 100", 100'" can also have magnets which, when suitably oriented in interaction with the first magnet 36 and the second magnet 36', exert attractive (correct orientation) or repulsive (incorrect orientation) forces on the respective additional battery pack 100', 100", 100'".
[0037] The control of the power bank 10 or the power bank module 12 in the form of control logic, indicated above by way of example in connection with Figure 1, is carried out by way of example in Figure 2 by a control controller 34, which is connected to the other components of the power bank module 12 arranged on the PCB 32 via conductor tracks (not shown) and can communicate with them. Of course, the control controller 34 is to be understood merely as an example, so that all or at least some of the described functionalities can also be implemented with separate electronic components. Complete integration into a single microchip is therefore conceivable but not required. For reasons of space, it is conceivable that the control controller 34 is arranged on the side of the PCB 32 opposite the battery ports 14, 14', 14", in order to save space.
[0038] Figure 3 shows a three-dimensional view of an exemplary battery pack 100. The battery pack 100 shown can be identical to the other battery packs 100', 100", 100'" with regard to its technical specifications, in particular its capacity, its internal structure, and its communication capability. However, in Figure 3, the battery pack 100 is not inserted into the power bank module 12, but is connected via a connecting plug 28 and a connecting cable 26 to an exemplary helmet light 30 shown three-dimensionally in Figure 4, which acts as an electrical consumer for the battery pack 100. At the same time, the battery pack 100 is connected to the power bank module 12 via the charging plug 24 with the connecting cable 22 already known from Figure 1, so that the battery pack 100 acts as an electrical consumer for the power bank 10, which is connected to a supply connection 16 of the power bank module 12 and is charged in this way.
[0039] The configuration described above, in which the helmet light 30 shown in Figure 4 is first electrically connected to the battery pack 100 and then the battery pack 100 is in turn connected to the power bank 10, ensures that the battery pack 100 remains substantially charged until the additional battery packs 100', 100", 100'" arranged in the power bank 10 are completely discharged. Even after removing the power bank 10 from the battery pack 100, i.e., by unplugging the charging plug 24 on the battery pack 100, there is no interruption in the power supply to the helmet light 30, which remains connected to the battery pack 100.
[0040] The power bank 10 can have retaining elements (not shown), such as loops, by which the power bank 10 can be attached to a belt, for example. It is also conceivable for the power bank 10 to have a hook-and-loop surface, with the aid of which it can be releasably secured, for example, in a storage bag. The storage bag can be, for example, an inside pocket of a jacket, such as a cut-resistant vest. The features of the invention disclosed in the above description, in the drawings, and in the claims can be essential for the implementation of the invention both individually and in any combination.
[0041] List of reference symbols
[0042] 10 power banks
[0043] 12 power bank module
[0044] 14 first battery port
[0045] 14' second battery port
[0046] 14" third battery port
[0047] 16 Supply connection
[0048] 16' additional supply connection
[0049] 16" additional supply connection
[0050] 18 Charging port
[0051] 20 charging cables
[0052] 22 connection charging cables
[0053] 24 charging plugs
[0054] 26 connecting cables
[0055] 28 connectors
[0056] 30 helmet light
[0057] 32 PCB
[0058] 34 control controllers
[0059] 36 first magnet
[0060] 36' second magnet
[0061] 38 connection contacts
[0062] 40 frames
[0063] 40' frame
[0064] 40" frame
[0065] 42 contact pins
[0066] 100 battery pack
[0067] 100' first additional battery pack
[0068] 100" second additional battery pack
[0069] 100'" third additional battery pack
Claims
Claims 1. A power bank module (12) comprising: a PCB (32) with a control controller (34) arranged thereon; a plurality of battery ports (14, 14', 14") arranged on the PCB (32), which are configured to establish a functional connection between a number of battery packs (100', 100", 100'") connectable to the plurality of battery ports (14, 14', 14") and the power bank module (12); at least one supply connection (16) arranged on the PCB (32) to which a load can be connected, wherein the supply connection (16) is configured to establish a functional connection between the connected load and the power bank module (12); a charging port (18) arranged on the PCB (32) to which a power source can be connected, wherein the charging port (18) is configured to establish a functional connection between the power source and the power bank module (12);wherein the control controller (34) is configured to control the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least one supply connection (16) and the charging connection (18) such that a closed circuit comprising the at least one supply connection (16) always comprises only one battery port of the plurality of battery ports (14, 14', 14"), while all others of the plurality of battery ports (14, 14', 14") are electrically separated from the supply connection (16); 2. The power bank module (12) of claim 1, wherein the control controller (34) is further configured to control the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the supply port (16), and the charging port (18) such that the battery port (14, 14', 14") encompassed by the closed circuit alternates cyclically.
3. Power bank module (12) according to claim 2, wherein the cyclical change between the battery ports (14, 14', 14") is time-controlled or based on another measurable parameter.
4. The power bank module (12) according to any one of claims 1 to 3, wherein the power bank module (12) comprises at least two supply connections (16, 16', 16"), and wherein the control controller (34) is configured to control the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least two supply connections (16, 16', 16"), and the charging connection (18) such that two separate closed circuits, each comprising one of the at least two supply connections (16, 16', 16"), always comprise only one battery port of the plurality of battery ports (14, 14', 14"), while all others of the plurality of battery ports (14, 14', 14") are electrically separated from the respective supply connection (16, 16', 16").
5. The power bank module (12) according to claim 4, wherein the control controller (34) is further configured to control the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least one supply connection (16, 16', 16"), and the charging connection (18) such that the battery port (14, 14', 14") encompassed by the two closed circuits alternates cyclically.
6. The power bank module (12) according to any one of claims 1 to 5, wherein the control controller (34) is further configured to control the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least one supply connection (16, 16', 16"), and the charging connection (18) such that the charging connection (18) and the at least one supply connection (16, 16', 16") are always electrically separated from one another, and such that a closed circuit comprising the charging connection (18) always comprises only one battery port of the plurality of battery ports (14, 14', 14"), while all other battery ports of the plurality of battery ports (14, 14', 14") are electrically separated from the charging connection (18).
7. The power bank module (12) according to any one of claims 1 to 6, wherein the plurality of battery ports (14, 14', 14") arranged on the PCB (32) each comprise a first magnet (36) and a second magnet (36').
8. Power bank (10) comprising a power bank module (12) according to one of claims 1 to 7, and at least two battery packs (100', 100", 100"') which are functionally connected to the power bank module (12).
9. A method for operating a power bank (10) according to claim 8, wherein, by a control controller (34), an opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least one supply connection (16, 16', 16") and the charging connection (18) is controlled such that a closed circuit comprising the at least one supply connection (16, 16', 16") always comprises only one battery port of the plurality of battery ports (14, 14', 14"), while all others of the plurality of battery ports (14, 14', 14") are electrically separated from the at least one supply connection (16, 16', 16").
10. The method according to claim 9, wherein the power bank module (12) comprises at least two supply connections (16, 16', 16"), and wherein, by the control controller (34), an opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least two supply connections (16, 16', 16") and the charging connection (18) is controlled such that two separate closed circuits, each comprising a supply connection of the at least two supply connections (16, 16', 16"), always comprise only one battery port of the plurality of battery ports (14, 14', 14"), while all others of the plurality of battery ports (14, 14', 14") are electrically separated from the respective supply connection of the at least two supply connections (16, 16', 16").
11. The method according to claim 9 or 10, wherein, by the control controller (34), the opening and closing of circuits between the plurality of battery ports (14, 14', 14"), the at least one supply connection (16, 16', 16") and the charging connection (18) is controlled such that the charging connection (18) and the at least one supply connection (16, 16', 16") are always electrically separated from one another, and that a closed circuit comprising the at least one charging connection (18) always comprises only one battery port of the plurality of battery ports (14, 14', 14"), while all the others of the plurality of battery ports (14, 14', 14") are electrically separated from the charging connection (18).