The present invention relates to a method for charging an accumulator by means of a charging apparatus, wherein the accumulator contains at least one energy storage cell, a first data interface and a wake-up circuit for activating control electronics of the accumulator, and the charging apparatus contains a second data interface, a controller, a timer and a switch apparatus, and wherein the data interfaces are connected to one another via a first and a second communication line for differential communication between the accumulator and the charging apparatus.

In addition, the present invention relates to a system containing an accumulator and a charging apparatus for performing the method according to the invention, wherein the accumulator contains at least one energy storage cell, a first data interface and a wake-up circuit for activating control electronics of the accumulator, and the charging apparatus contains a second data interface, a controller, a timer and a switch apparatus, and wherein the data interfaces are connected to one another via a communication line for differential communication between the accumulator and the charging apparatus.

Furthermore, the present invention relates to an accumulator for performing the method, wherein the accumulator contains at least one energy storage cell, a first data interface and a wake-up circuit for activating control electronics of the accumulator.

Further, the present invention relates to a charging apparatus for performing the method, wherein the charging apparatus contains a second data interface, a controller, a timer and a switch apparatus.

BACKGROUND

To store electrical energy in an accumulator (also called storage battery), the accumulator is connected to a mains-operated charging apparatus (also charger). Electrical energy in the form of a charging current flows through the charging apparatus to the accumulator and in particular to the individual storage battery cells of the accumulator.

The charging of an accumulator by means of the charging apparatus can be problematic, however, if the accumulator is almost completely discharged (i.e. less than 20% of the rated capacity) and additionally too hot (i.e. above 45° C.). A relatively long charging process, in which the accumulator is supposed to be almost completely charged again (i.e. more than 70% of the rated capacity), additionally increases the already critical temperature of the accumulator in this case. This problem arises in particular if the accumulator has been used intensively, i.e. with a long and high flow of current, as an energy source for a machine tool.

In order to protect the accumulator against possible damage when charging by means of the charging apparatus, the accumulator should be cooled before recharging and brought to below 45° C.

Possibly, however, a user does not detect the excessive temperature of an accumulator, which means that the excessively hot accumulator is recharged without appropriate cooling. Damage to the accumulator is possible as a result.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method for charging an accumulator by means of a charging apparatus that allows the aforementioned problems to be solved. In addition, it is an object of the present invention to provide a system containing an accumulator and a charging apparatus for performing the method that allows the aforementioned problem to be solved. Furthermore, it is an object of the present invention to provide an accumulator and a charging apparatus in order to solve the aforementioned problem.

The present invention provides a method for charging an accumulator by means of a charging apparatus, wherein the accumulator contains a wake-up circuit for waking control electronics of the accumulator, the charging apparatus contains a controller, a timer and a switch apparatus and wherein there is provision for a CAN data bus for differential communication between the accumulator and the charging apparatus.

According to the invention, the method contains the following method steps:setting the timer to a predetermined period of time;setting the control electronics of the accumulator to a deactivation mode, so that no charging current flows from the charging apparatus to the accumulator and no current flows from the at least one energy storage cell to the control electronics of the accumulator;sending at least one signal from the charging apparatus to the accumulator via the first and second communication lines after the predetermined period of time has elapsed;activating the wake-up circuit for activating control electronics by detecting a voltage value from the communication line, wherein the voltage value is consistent with either the dominant or recessive state of the first or second communication line;setting the control electronics to an activation mode by means of the wake-up circuit; andrequesting or releasing a charging current from the charging apparatus by means of the accumulator.

The effect that can be achieved thereby is that the accumulator can initially cool for a certain period of time before a charging process, even though it is already connected to the charging apparatus. As a result, the user does not need to check the accumulator for an excessive temperature and if need be initially cool the accumulator before the accumulator is connected to the charging apparatus to charge the accumulator. The setting of the timer in this case allows the charging process to begin automatically after the accumulator has had a certain time for cooling or has reached a certain temperature again. The cooling is achieved in particular in that the accumulator, after having been connected to the charging apparatus to recharge, is initially put into a switched-off mode or idle mode in which the control electronics of the accumulator are switched off and hence no further heat is generated in the accumulator. Additionally, no electric current flows from the energy storage cells to the control electronics either, which means that an energy storage cell that is already heavily discharged is not discharged further and possible damage to the approximately completely discharged energy storage cell can be avoided. As a result of the control electronics also not being supplied with electric current by the energy storage cells of the accumulator and consequently also not being activated thereby, the control electronics also cannot heat further.

The requesting or releasing of a charging current means that the accumulator is capable of receiving a charging current at a predetermined maximum current intensity from the charging apparatus. To this end, either an appropriate signal is sent from the accumulator to the charging apparatus indicating that a charging current at a maximum possible current intensity is supposed to flow to the accumulator, or the accumulator is capable, by measuring the current intensity of a charging current sent from the charging apparatus to the accumulator, of allowing the charging current to flow to the energy storage cells if the charging current has a current intensity below the maximum possible current intensity.

Optionally, the charging apparatus may be configured with a fan in order to cool the accumulator as appropriate before the actual charging process and after the timer has been set.

In accordance with an advantageous configuration of the present invention, it may be possible for the method step of setting the control electronics of the accumulator to a deactivation mode, so that no charging current flows from the charging apparatus to the accumulator, to be followed by a separate wake-up function of the charging apparatus for waking or activating the control electronics of the accumulator being deactivated. The deactivation of the wake-up function prevents the accumulator from being put back into an activation mode from the deactivation mode early. The accumulator's being activated or reactivated too early means that sufficient cooling of the accumulator cannot be ensured, for example.

In accordance with a further advantageous embodiment of the present invention, it may be possible for the method step of setting the timer to a predetermined period of time to be followed by a cooling apparatus being activated in order to cool parts of the accumulator and/or parts of the charging apparatus. The cooling apparatus can be a fan that is positioned in the charging apparatus such that ambient air for cooling can flow onto parts of the accumulator and/or parts of the charging apparatus. Alternatively, it may be advantageous for the cooling apparatus to be positioned in the accumulator in order to cool parts of the accumulator and/or parts of the charging apparatus.

In addition, the present invention provides a system containing an accumulator and a charging apparatus for performing the method, wherein the accumulator contains at least one energy storage cell, a first data interface and a wake-up circuit for activating control electronics of the accumulator, and the charging apparatus contains a second data interface, a controller, a timer and a switch apparatus, and wherein the data interfaces are connected to one another via a communication line for differential communication between the accumulator and the charging apparatus.

Furthermore, the present invention provides accumulator for performing the method, wherein the accumulator contains at least one energy storage cell, a first data interface and a wake-up circuit for activating control electronics of the accumulator.

In addition, the present invention provides a charging apparatus for performing the method, wherein the charging apparatus contains a second data interface, a controller, a timer and a switch apparatus.

Further advantages emerge from the description of the figures that follows. The figures depict various exemplary embodiments of the present invention. The figures, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to produce useful further combinations.

