BACKGROUND OF THE INVENTION

The invention proceeds from a method for checking the plausibility of an electronic circuit for time measurement of an electrochemical energy storage system, an electrochemical energy storage system and use of an electrochemical energy storage system.

Document U.S. Pat. No. 5,955,869 discloses a method for monitoring the remaining capacity of a rechargeable battery pack. In said method, two different processes are used to estimate the remaining capacity. In a first process, the data generated on the rechargeable battery pack are used to estimate the remaining rechargeable battery capacity; and in the second procedure, data transmitted from a host device to the battery pack are used to estimate the remaining battery capacity. The rechargeable battery alternates between said two processes under defined conditions and, in the preferred embodiment, which is described in detail in the present description, the battery block alternates from the first procedure to the second procedure when the battery current falls below a threshold value.

Document US 2018/183252 discloses a method and provides an apparatus for detecting a battery state of an electronic apparatus. The electronic apparatus comprises a battery, a charging circuit for charging the battery, a measurement circuit for testing a state of the battery and a processor, which is configured to charge the battery using the charging circuit in order to determine whether the charging process fulfils a preset condition.

SUMMARY OF THE INVENTION

The approach according to the invention in contrast has the advantage that the check for plausibility is effected by means of a cooling behavior of at least one electrochemical energy store during non-use of the electrochemical energy store, comprising the following steps:

a) detecting an ambient temperature TEnvof the electrochemical energy store;

b) detecting a temperature Tt0of the electrochemical energy store at the beginning of the non-use of the electrochemical energy store;

c) detecting a temperature Tt1of the electrochemical energy store at the beginning of a restart of the electrochemical energy store;

d) calculating a period toff of the non-use of the electrochemical energy store in accordance with the formula

toff=-τ*ln⁡(Tt⁢⁢1-TEnvTt⁢⁢0-TEnv),
wherein τ is a system constant, which comprises material properties of the electrochemical energy store in accordance with

τ=m*cpα*A,
wherein m is a mass, A is a contact area, α is a thermal conductivity and cpis a specific thermal capacity of the electrochemical energy store;

e) determining an overall error in the calculation of the period toffof the non-use of the electrochemical energy store in accordance with the formula Δtofferr=Δt1+Δt2+Δt3, whereinΔt1is a temperature measurement error during the restart of the electrochemical energy store,

Δt2is a temperature measurement error at the beginning of the non-use of the electrochemical energy store and

Δt3is a temperature measurement error of the ambient temperature;

f) checking the plausibility of the electronic circuit for time measurement by comparing a period toffClockof the non-use of the electrochemical energy store, which period is measured by the electronic circuit for time measurement, with the calculated period toffof the non-use of the electrochemical energy store; and

g) identifying an error in the electronic circuit for time measurement when Δtofferr<|toffClock−toff|.

The method for checking the plausibility of an electronic circuit for time measurement further can also comprise the following step:

h) generating an electrical, optical, acoustic and/or haptic signal when an error is identified in the electronic circuit for time measurement.

As a result thereof, for example, when an error is identified in the electronic circuit for time measurement, a user of the electrochemical energy storage system can be warned and/or the error can be stored for servicing purposes.

An electrochemical energy storage system advantageously comprises at least one electrochemical energy store, at least one sensor for detecting a temperature of the electrochemical energy store and/or an ambient temperature of the electrochemical energy store, an electronic circuit for time measurement and at least one means, in particular an electronic battery management control device, which is configured to carry out the steps of the method according to the invention.

A computer program advantageously comprises commands, which, when the computer program is executed by an electronic battery management control device, cause same to execute the method according to the invention.

The computer program is advantageously stored on a machine-readable storage medium.

An electrochemical energy storage system according to the invention is advantageously used for electric vehicles, hybrid vehicles, aircraft, plug-in hybrid vehicles, pedelecs or E-bikes, for portable telecommunications or data processing devices, for electrical hand tools or food processors, and in stationary stores for storing in particular regeneratively obtained electrical energy.

