Passive additional module for accumulators, accumulator with such a passive additional module and method for supplying energy to a passive additional module

Description

[0001] The invention relates to a passive additional module for accumulators, in particular lead-acid accumulators, with terminals for connection to two CAN bus data lines of a CAN bus-compatible charger for transmitting data packets.

[0002] Furthermore, the invention also relates to an accumulator, in particular a lead-acid accumulator, with at least two terminals which are connected via connecting lines to a charging plug for connection to a CAN bus-compatible charger with two CAN bus data lines for transmitting data packets.

[0003] Finally, the present invention relates to a method for supplying energy to a passive additional module for accumulators, in particular lead-acid accumulators, via which passive additional module the accumulator is provided with at least a unique identification or information about a charging method of the accumulator, via a CAN bus-compatible charger with two CAN bus data lines, via which data packets are transmitted.

[0004] Modern, rechargeable batteries or accumulators often have integrated electronics that can be used to support intelligent charging management. For example, modern lithium-ion batteries have battery management systems that contain certain data, such as the serial number or an identification (ID) of the battery, or information about the charging cycles, etc. Intelligent chargers, such as CAN bus-compatible chargers, can thus determine the identity of the accumulator and adapt the charging process to the respective accumulator, its age, or condition. For example, EP 3 482 998 A1 describes a system that enables the operation of an electric vehicle with different accumulators, whereby the accumulators are equipped with corresponding battery management systems and can be connected to a CAN bus.

[0005] For example, US 2014 / 0277887 A1 describes a method and a system for detecting the type and capacity of the accumulator and adapting the charging process for energy storage devices for electric vehicles.

[0006] US 2013 / 0116868 A1 describes a battery-powered vehicle and a battery maintenance system.

[0007] US 2019 / 117919 A1 discloses a respiratory therapy device which also involves a CAN bus connection, but does not contain any indication of the supply of an energy storage device of a passive additional module for a battery via the CAN bus data lines.

[0008] Finally, DE 10 2013 216 670 A1 describes a method for activating an on-board electrical system in a motor vehicle, wherein a corresponding control unit connected to a CAN bus performs the activation of the on-board electrical system. Details regarding the control unit's power supply are not disclosed.

[0009] Older batteries or certain types of batteries, such as lead-acid batteries, typically lack integrated electronics and therefore cannot be identified by intelligent chargers. Data such as serial numbers, number of charging cycles, etc., is not transferred from the battery to the charger, preventing intelligent charging management from being supported.

[0010] The object of the present invention is therefore to create the above-mentioned passive add-on module for rechargeable batteries, a rechargeable battery with such a passive add-on module, and a method for supplying power to such a passive add-on module for rechargeable batteries, by means of which an rechargeable battery without integrated electronics or a battery management system can be easily given an identity or a certain degree of intelligence. This should enable intelligent charging methods using CAN bus-compatible chargers, depending on the rechargeable battery to be charged. The passive add-on module should be as simple and cost-effective as possible and should not require its own independent power supply.After retrofitting a battery, especially a lead-acid battery, with the passive additional module, the advantages of CAN bus-compatible chargers should also be able to be used with such batteries and intelligent charging management should also be achievable with such batteries.

[0011] The object of the invention is achieved by an above-mentioned passive additional module, in which a CAN transceiver connected to the terminals for receiving and transmitting the data packets transmitted via the CAN bus data lines, a control device connected to the CAN transceiver, a voltage supply circuit for providing a supply voltage relative to a reference potential, an energy store and a data store connected to the control device for storing at least one unique identification or information about a charging process of the accumulator, and the voltage supply circuit is connected via the energy store to a charging circuit, and the charging circuit is connected to the control device and is designed toTo charge the energy storage device via the data packets sent by the CAN-bus-compatible charger, at least during communication pauses, via the voltage difference between a CAN-bus data line and the reference potential or between both CAN-bus data lines. According to the invention, the passive add-on module for accumulators has the option of communicating with the CAN bus of a CAN-bus-compatible charger. At least when no communication is taking place via the CAN bus data lines, the energy storage device of the passive add-on module is charged via the charger's CAN bus, explicitly via the voltage difference between a CAN-bus data line and the reference potential or the voltage difference between two CAN-bus data lines. Because the passive add-on module does not have its own batteries, manufacturing costs can be kept low.However, the maintenance effort for the passive add-on module can also be reduced to a minimum. Since no interventions are required in the area of the battery's connections and connecting cables during installation, retrofitting existing systems is very cost-effective and possible with little effort without compromising operational reliability. If the passive add-on module were powered via the battery's connections or connecting cables, operational reliability would only be guaranteed with greater technical effort. With the inventive power supply of the passive add-on module via the CAN bus data lines, the passive add-on module has no connection to the typically higher voltage potential of the battery. This means that operational reliability does not require additional effort. In particular, a unique serial number can be stored in the data memory of the passive add-on module.which can be used to identify the respective battery, or information about the number of charging cycles of the battery, information about the appropriate charging curve, and other information for intelligent battery management. A CAN bus-compatible charger can read the data storage of the passive additional module, process the read information, and, for example, adapt procedures, as well as change and write information to the data storage. A CAN bus-compatible charger connected to a computer network or the Internet can, using the unique serial number to identify the battery, obtain further battery-relevant information or instructions from a central or decentralized, for example, cloud-based data center, or send them to such a data center.that the charging of the energy storage device of the passive additional module is carried out at least during the pauses in communication via the CAN bus data lines, it is intended to express that even during communication via the CAN bus data lines, at least part of the energy content of the transmitted data can be used to charge the energy storage device.

[0012] This passive add-on module for rechargeable batteries is characterized by its relatively simple design and cost-effective manufacture. Furthermore, the passive add-on module can be constructed relatively compactly, which allows for quick and easy retrofitting to existing rechargeable batteries, particularly lead-acid batteries. For example, the passive add-on module can be mounted on the rechargeable battery's terminals or connecting cables or on an existing charging connector connected to the rechargeable battery. Of course, the passive add-on module can also be integrated into the rechargeable battery or charging connector during production. It should be noted at this point that a CAN bus essentially consists of the CAN-High and CAN-Low data lines.Generally, connectors for connecting the CAN bus data lines are used to connect additional lines, such as lines for so-called supply, pilot, or auxiliary contacts. Colloquially, these additional lines and their contacts are generally referred to in conjunction with the term "CAN bus." The term "CAN bus" is also often used in a generalized manner for a connection or connection to the CAN bus data lines, even if these include other lines besides these CAN bus data lines. For the sake of clarity, the CAN bus data lines are therefore referred to as CAN bus data lines. The passive add-on module has at least two connections for connecting to two CAN bus connections, namely the CAN bus data lines.

[0013] The connection of the passive additional module to a charger's CAN bus is usually established via a charging plug or charging coupling, through which the charging current for charging the battery flows. However, commercially available charging plugs usually have a limited number of connections for the CAN bus. Many common charging plugs can only be connected to two CAN bus connections (e.g. Anderson flat plugs). Since both connections of the charging plug are already occupied for communication via the CAN bus data lines, the option of conventional power supply via supply lines normally available for power supply is not available. For charging plugs with three or four CAN bus connections, power supply via the remaining CAN bus connections would be possible in addition to the CAN bus data lines.

[0014] By supplying power to the passive add-on module via the CAN bus data lines using data packets, instead of a dedicated power supply line, the spared connections on the charging connector can be used for other functions. The power and current of the power transmission via the CAN bus data lines are limited to such an extent that error messages or component damage are avoided.

[0015] The energy storage device of the passive add-on module is preferably formed by at least one capacitor. This represents a cost-effective and space-saving implementation of the energy storage device.

[0016] If the control device is connected to at least one port for connection to at least one sensor of the rechargeable battery, information about the condition of the rechargeable battery can be transmitted to the charger via the passive additional module. For example, a sensor can be a temperature sensor that can provide information about the thermal condition of the rechargeable battery. Instead of or in addition to one or more temperature sensors, further sensors can be provided, such as sensors for measuring voltage or the fill level of the rechargeable battery's electrolyte, or the like. This means that the respective condition of the rechargeable battery can be taken into account during a charging process with a CAN bus-capable charger, and if necessary, the charging current or charging voltage can be adapted to the respective condition, for example the existing temperature.

[0017] According to a further feature of the invention, the passive add-on module can be provided with a connector for connecting to a start / stop detector of the charger. This prevents the formation of an arc when connecting or disconnecting a battery to the charger. At the same time, it can be used to determine whether a passive add-on module or a battery is connected.

[0018] If necessary, the control device can be connected to an additional transceiver or a communication interface. This additional transceiver can, for example, be an NFC (Near Field Communication) transceiver. Using such an additional transceiver, which can be implemented both wired and wirelessly, it is possible to write data to the data memory of the passive additional module or read data from the data memory of the passive additional module, as well as to communicate directly with the control device. For example, a battery equipped with the passive additional module can be read using an NFC-enabled mobile phone with appropriate software or app, and information about the type, age, or capacity of the battery can be read out. In addition, e.g.When the passive additional module is newly attached to a battery, a specific serial number is assigned to it by writing this serial number from the NFC-enabled device into the data memory of the passive additional module.

[0019] The charging circuit preferably contains a diode at the input to prevent current flow from the charging circuit to the connection of the passive additional module.

[0020] Preferably, the charging circuit of the passive add-on module includes a current limiter. The current limiter is set to a value that prevents excessive charging current from flowing, at least during pauses in communication via the CAN bus, which could lead to a malfunction in the CAN bus-compatible charger.

[0021] The current limiter can be set to a current between 0 and a defined limit during communication via the CAN bus data lines. If the current limiter is set to a current of 0 amps, the energy storage device will not be charged via the charging circuit of the passive add-on module during communication via the CAN bus. If the energy storage device of the passive add-on module is completely discharged, a defined limit can also be set for the current with which the energy storage device is initially charged. If a certain amount of charging of the energy storage device of the passive add-on module is also to take place during communication via the CAN bus, a current limit is set in the current limiter that, on the one hand, allows a certain amount of charging of the energy storage device, but on the other hand, does not endanger communication via the CAN bus.Naturally, the charging of the energy storage device of the passive additional module occurs more slowly during communication via the CAN bus than during breaks in communication via the CAN bus, where more energy from the signals transmitted via the CAN bus can be used to charge the energy storage device due to a higher limit value of the current limiter.

[0022] The power supply circuit of the passive add-on module, which supplies all components with electrical energy, can be formed, for example, by a boost converter. The boost converter converts the voltage of the energy storage device to one or more voltage values required to supply the components of the passive add-on module with electrical energy.

[0023] The control device is preferably designed to switch off the CAN transceiver and charge the energy storage device via the charging circuit at the latest as soon as the voltage of the energy storage device falls below a lower threshold. In this way, depending on the charge level of the energy storage device of the passive additional module, switching can take place between communication via the CAN bus and pauses in communication. Whenever the voltage of the energy storage device falls below a lower threshold, the energy storage device is automatically charged via the CAN bus, thus ensuring that the passive additional module always functions properly. The control device can also be designed to activate the charging circuit during communication and to ensure that no more power is diverted from the communication signals for charging than is possible to maintain successful communication.The control unit detects if too much power is diverted from the communication signals for charging and reduces the charging current via the charging circuit.

[0024] If the control device is also designed to switch on the CAN transceiver at the latest as soon as an upper threshold value of the voltage of the energy storage device has been exceeded, the communication can be switched over automatically, since charging of the energy storage device is not necessary.

[0025] According to a further feature of the invention, the passive add-on module has a housing with at least one recess for accommodating at least one connecting cable of the battery. This feature facilitates the attachment of the passive add-on module to an existing battery.

[0026] If at least one fastening element, for example a cable tie or the like, can be fastened to the housing above the at least one recess, the passive additional module can be fixed in a suitable manner to the at least one connecting cable of the accumulator.

[0027] The object of the invention is also achieved by an above-mentioned accumulator, in particular a lead-acid accumulator, with at least two terminals, which are connected via connecting lines to a charging plug for connection to a CAN bus-compatible charger with two CAN bus data lines for transmitting data packets, in which a passive additional module as described above is provided with terminals for connection to the two CAN bus data lines of the CAN bus-compatible charger. The passive additional module provides the accumulator with at least one unique identification option. In particular, existing accumulators can be retrofitted with the passive additional module. For further advantages, reference is made to the above description of the passive additional module.

[0028] Two connecting cables or a single two-wire connecting cable with a corresponding charging plug can be arranged at the battery terminals. The passive add-on module is preferably attached to at least one connecting cable. This solution is particularly advantageous when retrofitting existing batteries. With new batteries, the passive add-on module can, of course, also be integrated into the battery or its housing.

[0029] As already mentioned above, at least one temperature sensor can be provided in the battery, which is connected to the passive additional module. As also mentioned above, this allows charging with a CAN bus-compatible charger to take the current temperature state of the battery into account, thus ensuring particularly gentle charging of the battery.

[0030] Finally, the object of the invention is also achieved by a method for supplying energy to a passive add-on module for rechargeable batteries, via which passive add-on module the rechargeable battery is provided with at least a unique identification or information about a charging method for the rechargeable battery, in which, at least during pauses in communication via the CAN bus data lines, an energy storage device is charged via a charging circuit using the data packets sent by the CAN bus-compatible charger via a voltage difference between a CAN bus data line and a reference potential or between two CAN bus data lines. As a result, no active energy source is required in the passive add-on module, and yet, when the rechargeable battery connected to the passive add-on module is connected to the charger via the charging plug, rapid charging of the energy storage device in the passive add-on module is ensured.This ensures that the passive add-on module functions whenever it is needed. When the charger is first connected to the accumulator equipped with the passive add-on module via a charging plug or charging coupling, the passive add-on module's energy storage device is initially charged, ensuring that all components are supplied with electrical energy. At least during pauses in communication via the CAN bus data lines, the passive add-on module's energy storage device is charged using the energy content of the data packets sent over the CAN bus data lines. Ideally, the data transmitted during pauses in communication is selected so that the transmitted data contains as much energy as possible, in order to charge the passive add-on module's energy storage device as quickly as possible.In the CAN protocol, the length of the transmitted data packets is typically limited, which is why a large number of data packets or charging messages are usually transmitted over the CAN bus data lines. With data containing as many logical "0"s as possible, more energy can be transmitted in a shorter time due to the higher voltage difference.

[0031] If the voltage of the energy storage device is measured and communication via the CAN bus data lines is switched off at the latest and the energy storage device is charged via the charging circuit when a lower threshold value of the voltage of the energy storage device is undershot, the communication function can be switched over to the charging function automatically.

[0032] If the energy storage voltage is measured and communication via the CAN bus data lines is activated at the latest when an upper threshold of the energy storage voltage is exceeded, an automatic switchover from the charging function to the communication function can also occur. A combination of these two functions enables automatic charging of the passive add-on module's energy storage whenever necessary. When the passive add-on module has sufficient energy, communication via the CAN bus is enabled, and data can be exchanged between the passive add-on module and the CAN bus-compatible charger.

[0033] When communication via the CAN bus data lines is enabled, a signal can be transmitted via the CAN bus data lines. In this variant, the passive add-on module sends a signal, for example, to the CAN bus-compatible charger to inform it that the passive add-on module's energy storage unit has been sufficiently charged. Upon receiving this signal, the CAN bus-compatible charger can automatically switch to communication mode and send specific information to the battery equipped with the passive add-on module, or exchange information between the battery and the charger.

[0034] The present invention is explained in more detail with reference to the accompanying drawings, in which: Fig. 1 shows a schematic diagram of a passive additional module according to the invention for a rechargeable battery, which is connected to a CAN bus-compatible charger; Fig. 2 shows a block diagram of an embodiment of a passive additional module for rechargeable batteries; Fig. 3 shows a block diagram of an extended embodiment of a passive additional module for a rechargeable battery; Fig. 4 shows timing diagrams of the voltage of the energy storage device of the passive additional module and the CAN bus data lines to illustrate the method according to the invention for charging the energy storage device of the passive additional module via the CAN bus data lines; Fig. 5 shows an embodiment of the housing of a passive additional module; Fig. 6 shows the passive additional module according to Fig. 5 , which is attached to the connecting cables of a battery; Fig. 7 a schematic connection by means of charging plug and charging socket in connected state; and Fig. 8 the schematic connection according to Fig. 7 in a partially open state.

[0035] Fig. 1 shows a schematic diagram of a passive additional module 1 according to the invention for a battery 2, which is connected to a CAN bus-compatible charger 6. The passive additional module 1 has at least two connections 3, 3', via which the passive additional module 1 can be connected to two CAN bus data lines CAN H, CAN L of a CAN bus-compatible charger 6. The passive additional module 1 is connected in a suitable manner to the battery 2, for example, to the respective charging plug 25 (see Fig. 3 and 6) on the side of the accumulator 2 or can also be integrated into it, as indicated by the dash-dotted line. Because the passive additional module 1 contains information, such as a unique identification or information about the suitable charging method for the accumulator 2, a CAN bus-compatible charger 6 can also be used for the intelligent charging of accumulators 2 without their own battery management system. In particular with lead-acid batteries, which are frequently used for industrial trucks in intralogistics, this allows simple battery management to be created. In the simplest case, the data memory 10 (see Fig. 2 ) of the passive additional module 1 a unique identification, which gives the accumulator 2 a unique identity.

[0036] In Fig. 2 is a block diagram of an embodiment of a passive additional module 1 for accumulators 2. A CAN transceiver 4 is connected to the terminals 3, 3', which receives the data from the CAN transceiver 40 of the charger 6 (see Fig. 3 ) or sends it to the CAN transceiver 40 of the charger 6. The CAN transceiver 4 is connected to the control device 8 of the passive additional module 1. Also connected to the control device 8 is a data memory 10, which can contain at least a unique identification or information on the suitable charging method of a rechargeable battery 2. A CAN bus-compatible charger 6 connected to the passive additional module 1 can read the data memory 10, process the read information and, for example, adapt a charging method accordingly, as well as change and write information on the data memory 10. For example, this can be connected to a computer network orThe CAN bus-compatible charger 6 connected to the Internet can use the unique serial number stored in the data memory 10 to identify the rechargeable battery 2 to obtain further information or instructions relevant to the rechargeable battery 2 from a central or decentralized, for example, cloud-based, data center or send them to such a data center. In a further embodiment, information about the nominal voltage of the rechargeable battery 2 can also be stored in the data memory 10 of the passive additional module 1. Using the information about the nominal voltage of the rechargeable battery 2, the CAN bus-compatible charger 6 is able to adapt or select a charging voltage or charging curve accordingly.

[0037] According to the invention, a charging circuit 5 is connected to at least one of the terminals 3 or 3', which is controlled accordingly via the control device 8. The charging circuit 5, which in the simplest case can be implemented by a series resistor (current limiter) and a diode to prevent discharge (see Fig. 3 ), is connected to an energy storage device 9, for example a capacitor or the like, in which the amount of energy required to supply the components of the passive additional module 1 can be stored. The energy storage device 9, in turn, is connected to a voltage supply circuit 7, which supplies all components of the passive additional module 1 with the required supply voltage V b or the required voltages relative to a reference potential GND. The voltage supply circuit 7 can, for example, be a boost converter that increases the voltage of the energy storage device 9 to a level required for the components of the passive additional module 1.According to the invention, the charging circuit 5 is designed to charge the energy storage device 9 by the CAN bus-compatible charging device 6, at least during the pauses in communication, via the voltage difference between a CAN bus data line CAN H, CAN L and the reference potential GND or the voltage difference between the two CAN bus data lines CAN H, CAN L. The control device 8 thus detects via the CAN transceiver 4 when no communication is taking place via the CAN bus and controls the charging circuit 5 accordingly, so that charging of the energy storage device 9 can take place at least during the pauses in communication via the CAN bus or the two CAN bus data lines CAN H, CAN L. In the simplest case, the control device 8 controls a corresponding switch 26 (see . Fig. 3 ) in the charging circuit 5, so that at least during the pauses in communication via the CAN bus, energy can flow via the charging circuit 5 into the energy storage device 9. In the exemplary embodiment shown, the charging current flows from the CAN bus data line CAN H via the charging circuit 5 to the energy storage device 9 and via the reference potential GND back via a resistor or a diode to the CAN bus data line CAN L . According to the invention, the passive additional module 1 is therefore supplied with appropriate energy via CAN bus data sent by the CAN bus-compatible charging device 6, which energy ensures the function of the passive additional module 1. In this way, an accumulator 2 which does not have its own battery management system can be easily retrofitted without having to use the energy from the accumulator 2 via the charging lines.Lead-acid batteries, in particular, usually do not have battery management systems and can therefore be retrofitted in a simple and cost-effective manner to enable suitable charging with CAN bus-compatible chargers 6. In the embodiment according to . Fig. 2 the passive additional module 1 is only connected to the CAN bus-compatible charger 6 via the two CAN bus data lines CAN H, CAN L.

[0038] Fig. 3 shows a block diagram of an extended embodiment of a passive additional module 1 for an accumulator 2. In addition to the embodiment according to Fig. 2 The passive additional module 1 includes a connector 12 for connecting to a sensor 13 of the accumulator 2, for example, a temperature sensor. This allows information about the thermal state of the accumulator 2 to be transmitted to the passive additional module 1, which can be taken into account when charging with the CAN bus-compatible charger 6. If multiple sensors 13 are arranged in the accumulator 2, multiple connectors 12 for connecting these sensors 13 can also be provided in the passive additional module 1, which are connected to the control device 8.

[0039] Furthermore, the passive additional module 1 is provided with a connection 14 for connecting to a start / stop detector 27 of the charger 6. This prevents the formation of an arc when connecting and disconnecting the battery 2 and thus protects the contacts of the charging plug 25 (see explanations of Fig. 7 und 8 ).

[0040] The control device 8 can be connected to a further transceiver 15 or a communication interface in order to be able to read the data memory 10 or to write data into the data memory 10. The further transceiver 15 or the communication interface can be wired or wireless, in particular formed by an NFC (Near Field Communication) transceiver. A passive additional module 1 designed in this way can also serve as a simple interface or simple translator between NFC and CAN bus, by means of which communication is enabled between an NFC-enabled terminal and another CAN bus-compatible device. Such a translator can be designed for direct connection to the CAN bus connection of a CAN bus-compatible device and is therefore not necessarily subject to the aforementioned restrictions that arise from charging plugs. For example, a service technician who, for example,has refilled the electrolyte of a rechargeable battery 2, communicate the completed refill to the charger 6 using an NFC-enabled device. This can serve the purpose of documentation or the purpose of adapting the charging process by the charger 6. The CAN bus-compatible charger 6 can, in turn, transmit information about the passive additional module 1, for example, its status, utilization, or irregularities during charging, to an NFC-enabled device. A CAN bus-compatible charger 6 can also read and write the data memory 10 of the passive additional module 1.

[0041] The charging circuit 5 according to the invention preferably has a diode 16, which prevents a current flow from the charging circuit 5 to the connection 3 of the passive additional module 1. Furthermore, the charging circuit 5 contains a current limiter 17 (for example a resistor) which limits the current flow during charging of the energy storage device 9 to a limit value IG, so that no malfunctions occur in the CAN bus-compatible charging device 6 due to an impermissibly high current I. If charging of the energy storage device 9, which can be implemented, for example, by appropriate capacitors 11, is to be prevented or switched off during communication via the CAN bus, the current limiter 17 is set to a limit value IG = 0 amperes during communication via the CAN bus data lines CAN H, CAN L. The charging circuit 5 can contain a switch 26, which is controlled accordingly by the control device 8.The switch 26 falls into the closed state when the energy storage device 9 of the passive add-on module 1 is empty or has too little charge to keep the switch 26 open. This ensures that a de-energized passive add-on module 1 is ready to charge even when the control device 8 is not active. When the control device 8 is not active, the charging circuit 5 limits the charging current to a maximum current that does not cause overload or a faulty condition. If the passive add-on module 1 is supplied with sufficient energy and the control device 8 is thereby activated, the control device 8 controls the switch 26 via the control line 30 and optionally limits the charging current of the charging circuit 5.

[0042] Alternatively, in another embodiment, the function of switch 26 can also be performed by current limiter 17. For this purpose, current limiter 17 is designed to be controllable or adjustable. This control is carried out via control line 30 (not shown).

[0043] The voltage supply circuit 7, which is connected to the energy storage device 9, can have a boost converter and possibly other circuits in order to be able to provide the voltage or voltages required to supply all components of the passive additional module 1. When the voltage VC of the energy storage device 9 relative to the reference potential GND is detected by the control device 8 (see dashed line between the energy storage device 9 and the control device 8), the charging circuit 5 can be activated and deactivated by the control device 8 depending on the charge state of the energy storage device 9 and can automatically switch between a charge state and a communication state (see Fig. 4 ). The communication state can also be maintained and, with appropriately controlled current limitation, charged during the process. A corresponding "CAN Enable" signal is transmitted to the CAN transceiver 4 via a control line 29 (see Fig. 4 ).

[0044] The energy storage device 9 is charged via the CAN bus compatible charger 6, at least during communication breaks, via the voltage difference between a CAN bus data line CAN H, CAN L and the reference potential GND or via the voltage difference between the two CAN bus data lines CAN H, CAN L. Since the voltage difference between the CAN bus data line CAN H and the reference potential GND is the largest, this is particularly suitable for charging the energy storage device 9. This preferred variant is shown in Fig. 3 shown. The charging current for charging the energy storage device 9 or capacitor 11 flows, at least during the pauses in communication, via the CAN bus data lines CAN H, CAN L from the CAN bus data line CAN H via the connection 3 into the charging circuit 5 or its diode 16, current limiter 17 and the closed switch 26 into the capacitor 11 as energy storage device 9 and via the reference potential GND back via the connections 14 to the reference potential GND in the CAN bus-compatible charging device 6. A pause in communication occurs, for example, when the passive additional module 1 is not sending any messages or receiving any information.For example, a pause in communication can have various states: the energy storage device 9 of the passive additional module 1 is not sufficiently charged or empty; the CAN transceiver 4 in the passive additional module 1 is deactivated; the passive additional module 1 does not signal readiness for communication or is not connected to a CAN bus-compatible charger 6; the CAN transceiver 40 in the CAN bus-compatible charger 6 sends charging messages. During pauses in communication, the CAN transceiver 40 in the charger 6 sends charging messages, which can be used by a connected passive additional module 1 to charge the energy storage device 9. From the perspective of the invention, sending or receiving charging messages does not constitute communication. The passive additional module 1 signals readiness for communication to the CAN bus-compatible charger 6 as soon as the energy storage device 9 is sufficiently charged.Because a passive additional module 1 is connected, the charger 6 recognizes whether the sending of charging messages to the passive additional module 1 should continue or whether it should proceed to sending queries, commands or information. To signal that the information has been received, understood or processed by the passive additional module 1, the passive additional module 1 sends a confirmation signal back to the charger 6. If the passive additional module 1 interrupts its readiness to receive or the processing during reception or processing, for example to charge the energy storage device 9, the charger 6 no longer receives a confirmation signal. If the confirmation signal is missing, the charger 6 continues to send charging messages until the passive additional module 1 signals to the charger 6 that it is ready to communicate again. The charger 6 can then resume communication from the point where it was previously interrupted.During a subsequent pause in communication, the charger 6 sends charging messages. A passive add-on module 1 that is ready for communication can, after receiving charging messages for a longer period, decide that communication readiness is not currently required and to charge the energy storage device 9 if it is not fully charged. In the embodiment according to . Fig. 3 the passive additional module 1 is connected to the CAN bus-compatible charger 6 via the two CAN bus data lines CAN H, CAN L and at least one further, here two further data lines, i.e. a total of four lines.

[0045] In Fig. 4 Time diagrams of the voltage of the energy storage device 9 of the passive additional module 1 and the CAN bus data lines CAN H, CAN L are drawn to illustrate the inventive method for charging the energy storage device 9 of the passive additional module 1 via the CAN bus data lines CAN H, CAN L. The control device 8 measures the voltage VC relative to the reference potential GND at the energy storage device 9. As soon as an upper threshold value VC,o of the voltage VC of the energy storage device 9 has been reached or exceeded, communication via the CAN bus data lines CAN H, CAN L is switched on by activating a corresponding "CAN Enable" signal on the control line 29. When communication via the CAN bus data lines CAN H, CAN L is activated, charging via the charging circuit 5 can be deactivated at the same time by switching the switch 26 in the charging circuit 5 (see Fig. 3 ) is deactivated or opened via the control line 30. As soon as the voltage VC at the energy storage device 9 reaches or falls below a predetermined lower threshold value VC,u, communication via the CAN bus data lines CAN H, CAN L can be switched off again by switching off the "CAN Enable" signal on the control line 29 and by activating or closing the switch 26 via the control line 30 of the charging circuit 5, charging of the energy storage device 9 via the CAN bus data lines CAN H, CAN L is enabled.

[0046] The closing of switch 26 by control device 8 and an optionally associated pause in communication does not depend exclusively on the value falling below the threshold value VC,u. The passive additional module 1 can also decide to emit a signal above VC,u, even before VC,o is reached, to signal to charger 6 that it is ready for communication. This can particularly shorten the waiting time until the first communication between charger 6 and passive additional module 1, whereby charger 6 can query the serial number, ID, or nominal voltage of a rechargeable battery 2 as quickly as possible. While charger 6 makes initial preparations for charging rechargeable battery 2 after receiving this information, orhas already started charging, the energy storage device 9 of the passive additional module 1 can be further charged in order to subsequently provide sufficient energy for more complex tasks of the passive additional module 1, as well as to enable longer communication without interruption.

[0047] Fig. 5 shows an embodiment of the housing 19 of a passive add-on module 1. The housing 19 has at least one recess 20 in which at least one connecting cable 21 of the accumulator 2 can be received, in order to support quick and easy attachment of the passive add-on module 1 to the respective accumulator 2. The passive add-on module 1 can be attached to the connecting cables 21 via fastening elements 22. Fig. 6 shows the passive additional module 1 according to Fig. 5 , which is attached to the connecting lines 21 of a rechargeable battery 2. The connecting lines 21 run from the connections 23, 24 of the rechargeable battery 2 to the charging plug 25 at the end of the connecting lines 21. In addition to the at least one recess 20 on the housing 19, fastening elements 22, such as cable ties or the like, can be attached to the housing 19 so that the passive additional module 1 or the housing 19 can be firmly connected to the at least one connecting line 21 of the rechargeable battery 2. In the example shown, the rechargeable battery 2 has two connecting lines 21 which run through corresponding recesses 20 on the housing 19 of the passive additional module 1 and are fixed with corresponding fastening elements 22. At least one connecting line 34 for connecting the passive additional module 1 to a sensor 13 (not shown) located in the rechargeable battery can also be provided between the passive additional module 1 and the rechargeable battery 2.The passive additional module 1 can be connected to the charging plug 25 via a connecting cable 33.

[0048] Finally, in the Fig. 7 und Fig. 8 A connection of a charging plug 25 of a rechargeable battery 2 to a corresponding charging socket 25' of a CAN bus-compatible charger 6 is schematically shown in a connected and a partially open state. The charging plug 25 connected to the rechargeable battery 2 contains the corresponding contacts for the connection to the connecting lines 21 of the rechargeable battery 2 and four contacts 35 for the connection to the CAN bus connections. The charging socket 25' connected to the CAN bus-compatible charger 6 contains the corresponding contacts for the connection to the connecting lines 21' of the CAN bus-compatible charger 6 and three contacts 35' for the connection to the CAN bus connections on the CAN bus-compatible charger 6 side. One contact 32' is somewhat shorter than the remaining contacts 35' for the connection to the CAN bus connections of the CAN bus-compatible charger 6.This shortened contact 32' is connected to the start / stop detector 27 in the CAN bus compatible charger 6 (see . Fig. 3 ).

[0049] In Fig. 7 The charging plug 25 and the charging socket 25' are fully inserted into each other or connected to each other, and all contacts are making corresponding contact. Contact 32' connected to the start / stop detector 27 in the CAN bus-compatible charger 6 is also in contact with one of the four contacts 35 in the charging plug 25.

[0050] In the partially opened state of the charging plug 25 and the charging socket 25' according to Fig. 8The shortened contact 32' of the charging socket 25' is separated from the corresponding contact 35 on the charging plug 25 earlier, before the remaining contacts 35, 35' of the CAN bus have been opened. This allows the start / stop detector 27 in the CAN bus-compatible charger 6 to detect the separation, and the charging current can be shut off before the contacts 21, 21' are separated. This prevents arcing between the contacts when the charging plug 25 is separated from the charging socket 25', thus increasing the service life of the components.

[0051] The passive add-on module 1 according to the invention can be easily arranged on existing accumulators 2, whereby the accumulator 2 can be recognized by the CAN bus-compatible charger 6, and battery or charging management can be carried out according to the recognized accumulator 2. The passive add-on module 1 is supplied with electrical energy via the CAN bus data lines CAN H, CAN L of the CAN bus-compatible charger 6 and thus does not require its own active energy source, which correspondingly reduces the manufacturing costs of the passive add-on module 1 and the need for maintenance.

Claims

1. Passive add-on module (1) for accumulators (2), in particular lead accumulators, with terminals (3, 3') for connection to at least two CAN bus data lines (CANH, CANL) of a CAN-bus-compatible charger (6), characterized in that a CAN transceiver (4) connected to the terminals (3, 3') for receiving and sending information transmitted via the CAN bus data lines (CANH, CANL), a control device (8) connected to the CAN transceiver (4), a voltage-supply circuit (7) for providing a supply voltage (Vb) with respect to a reference potential (GND), an energy storage (9) and a data memory (10) connected to the control device (8) for storing at least one unique identification or information about a charging method of the accumulator (2) are provided, and in that the voltage-supply circuit (7) is connected via the energy storage (9) to a charging circuit (5), wherein the charging circuit (5) is connected to the control device (8) and is configured to charge the energy storage (9) by means of the CAN-bus-compatible charger (6) at least during the pauses of a communication via the voltage difference between a CAN bus data line (CANH, CANL) and the reference potential (GND) or between two CAN bus data lines (CANH, CANL).

2. Passive add-on module (1) according to claim 1, characterized in that the control device (8) is connected to at least one terminal (12) for connection to at least one sensor (13) of the accumulator (2).

3. Passive add-on module (1) according to claim 1 or 2, characterized in that a terminal (14) for connection to a start / stop detector (27) of the charger (6) is provided.

4. Passive add-on module (1) according to any one of claims 1 to 3, characterized in that the control device (8) is connected to a further transceiver (15), in particular an NFC (Near Field Communication) transceiver.

5. Passive add-on module (1) according to any one of claims 1 to 4, characterized in that the charging circuit (5) comprise a current limiter (17).

6. Passive add-on module (1) according to claim 5, characterized in that the current limiter (17) is adjustable to a current (I) between 0 and a defined limit value (IG) during the communication via the CAN bus data lines (CANH, CANL) .

7. Passive add-on module (1) according to any one of claims 1 to 6, characterized in that the control device (8) is configured to switch off the CAN transceiver (4) at the latest and to charge the energy storage (9) via the charging circuit (5) as soon as a lower threshold value (Vc,u) of the voltage (Vc) of the energy storage (9) is undershot.

8. Passive add-on module (1) according to any one of claims 1 to 7, characterized in that the control device (8) is configured to switch on the CAN transceiver (4) at the latest as soon as an upper threshold value (Vc,o) of the voltage (Vc) of the energy storage (9) is exceeded.

9. Passive add-on module (1) according to any one of claims 1 to 8, characterized in that a housing (19) with at least one recess (20) for receiving at least one connection line (21) of the accumulator (2) is provided.

10. Passive add-on module (1) according to claim 9, characterized in that at least one fastening element (22), for example a cable tie or the like, can be fastened on the housing (19) above the at least one recess (20).

11. Accumulator (2), in particular a lead accumulator, with at least two terminals (23, 24) which are connected via connection lines (21) to a charging plug (25) for connection to a CAN-bus-compatible charger (6) with at least two CAN bus data lines (CANH, CANL), characterized in that a passive add-on module (1) with terminals (3, 3') for connection to the at least two CAN bus data lines (CANH, CANL) of the CAN-bus-compatible charger (6) according to any one of claims 1 to 10 is provided.

12. Method for powering a passive add-on module (1) for accumulators (2), in particular lead accumulators, via which passive add-on module (1) at least a unique identification or information about a charging method of the accumulator (2) is provided to the accumulator (2), by means of a CAN-bus-compatible charger (6) with at least two CAN bus data lines (CANH, CANL), characterized in that at least during the pauses of a communication via the CAN bus data lines (CANH, CANL) an energy storage (9) is charged via a charging circuit (5) by means of a voltage difference between a CAN bus data line (CANH, CANL) and a reference potential (GND) or between two bus data lines (CANH, CANL).

13. Method according to claim 12, characterized in that the voltage (Vc) of the energy storage (9) with respect to the reference potential (GND) is measured and the communication via the CAN bus data lines (CANH, CANL) is switched off at the latest and the energy storage (9) is charged via the charging circuit (5) when a lower threshold value (Vc,u) of the voltage (Vc) of the energy storage (9) is undershot.

14. Method according to claim 12 or 13, characterized in that the voltage (Vc) of the energy storage (9) with respect to the reference potential (GND) is measured and the communication via the CAN bus data lines (CANH, CANL) is switched on at the latest when an upper threshold value (Vc,o) of the voltage (Vc) of the energy storage (9) is exceeded.

15. Method according to any one of claims 12 to 14, characterized in that a signal is emitted via the CAN bus data lines (CANH, CANL) when the communication via the CAN bus data lines (CANH, CANL) is switched on.