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EP-4386404-B1 - CONSUMPTION METER AND CONSUMPTION METER SYSTEM

EP4386404B1EP 4386404 B1EP4386404 B1EP 4386404B1EP-4386404-B1

Inventors

  • JENSEN, Mads Erik Lund
  • SAVOLAINEN, Juha-matti

Dates

Publication Date
20260506
Application Date
20221215

Claims (15)

  1. Consumption meter (2) comprising a battery (7) for energy supply, a temperature sensor (2) and an accumulation module (10), wherein the accumulation module (10) is configured for accumulating a first quantity over a time period to obtain a first accumulated quantity, wherein the first quantity is based on a product of at least a current drawn from the battery and a duration over which the current was drawn from the battery (7), and wherein the accumulation module (10) is further configured for transmitting the first accumulated quantity at regular or irregular intervals to a battery lifetime estimation module for calculating a remaining battery lifetime on basis of a nominal battery capacity, the received first accumulated quantity and an operating time of the battery (7), characterized in that the accumulation module (10) is configured for accumulating a second quantity over a time period to obtain a second accumulated quantity, wherein the second quantity is a product of a temperature at the consumption meter (2) and a duration for which the temperature was observed, and for transmitting the second accumulated quantity to the battery lifetime estimation module (3) for calculating a remaining battery lifetime additionally based on the received second accumulated quantity.
  2. Consumption meter (2) according to claim 1, wherein the first quantity is based at least on a product of the current drawn from the battery (7) and the duration over which the current was drawn from the battery (7) and preferably also a voltage at which the current was supplied from the battery (7).
  3. Consumption meter (2) according to claim 1 or 2, wherein the accumulation module (10) is configured for estimating the first quantity based on an operation of the consumption meter (2) or wherein the consumption meter (2) comprises means for measuring the current drawn from the battery (7), wherein the consumption meter (2) preferably comprises means for measuring a voltage at which the current is supplied by the battery (7) and/or means for measuring the duration over which the current is drawn from the battery (7).
  4. Consumption meter (2) according to any of the preceding claims, wherein the accumulation module (10) is further configured for determining the first quantity based on a temperature sensed by the temperature sensor (11).
  5. Consumption meter (2) according to any of the preceding claims, wherein the accumulation module (10) is configured for accumulating the one or more quantities from the time the battery (7) is initially placed in the consumption meter (2) until the battery (7) is removed from the consumption meter (2) or Wherein the accumulation module (10) is configured for accumulating the one or more quantities over the entire lifetime of the consumption meter (2).
  6. Consumption meter system (1) comprising a consumption meter (2) according to any of the preceding claims and a battery lifetime estimation module (3), wherein said battery lifetime estimation module (3) is configured for receiving the first accumulated quantity from the accumulation module (10) and calculating a remaining battery lifetime on basis of a nominal battery capacity, the received first accumulated quantity and an overall operating time of the battery (7).
  7. Consumption meter system (1) according to claim 6, wherein the battery lifetime estimation module (3) is configured for calculating the remaining battery lifetime by subtracting the first accumulated quantity last received from an available battery capacity to obtain a remaining battery capacity and estimating the remaining battery life by dividing the remaining battery capacity by an expected future discharge of the battery (7).
  8. Consumption meter system (1) according to claim 7, wherein the battery lifetime estimation module (3) is configured for estimating the available battery capacity by applying a correction factor to the nominal battery capacity, wherein the battery lifetime estimation module (3) is preferably configured for calculating an average current drawn from the battery based on the received first accumulated quantity and determining the correction factor for estimating the available battery capacity based on the calculated average current and/or wherein the battery lifetime estimation module (3) is preferably configured for determining the correction factor based on a peak current drawn from the battery (7).
  9. Consumption meter system (1) according to any of claims 6 to 8 comprising a consumption meter (2) according to claim 4, wherein the battery lifetime estimation module (3) is configured for receiving the second accumulated quantity from the accumulation module (10) and calculating a remaining battery lifetime also on basis of the received second accumulated quantity, wherein the battery lifetime estimation module (3) is preferably configured for correcting a received first accumulated value based on a received second accumulated value to account for temperature-dependent current consumption and/or wherein the battery lifetime estimation module (3) is preferably configured for determining the correction factor based on the received second accumulated quantity.
  10. Consumption meter system (1) according to claims 9, wherein the battery lifetime estimation module (3) is configured for calculating the correction factor based on all second accumulated quantities received since the battery (7) has been placed in the meter.
  11. Consumption meter system (1) according to any of claims 6 to 10, wherein the battery lifetime estimation module (3) is configured for estimating the expected future discharge based on at least some of the received first accumulated quantities and preferably by estimating the expected future discharge from selected received first accumulated quantities, wherein further preferably an average of at least some of the received first accumulated quantities is determined.
  12. Consumption meter system (1) according to claim 11, wherein the battery lifetime estimation module (3) is configured for excluding at least some of the received first and/or second accumulated quantities when estimating the expected future discharge.
  13. Consumption meter system (1) according to any of claims 6 to 12, wherein the consumption meter (1) comprises the battery lifetime estimation module (3).
  14. Consumption meter system (1) according to any of claims 6 to 12, wherein the battery lifetime estimation module (3) is part of an external control device which is arranged remotely from the consumption meter (2).
  15. Consumption meter system (1) according to claim 14, wherein the battery lifetime estimation module (3) is configured to estimate the remaining battery lifetime of the batteries (7) of a plurality of consumption meters (2).

Description

The present invention is directed to a consumption meter comprising a battery for energy supply and an accumulation module. The invention is further directed to a consumption meter system comprising a consumption meter and a battery lifetime estimation module. Consumption meters for measuring the consumption of, for example, heat, cooling liquid, gas or water are well-known in the prior art. Originally, these meters were purely mechanical meters. However, today's meters operate electronically and thus require a power source such as a battery. The battery may be used to power the actual metering circuitry which measures the consumption. Further, the battery may be provided to power a display which shows the current status of the meter and, in particular, the consumption of water, heat or cooling liquid measured by the meter. Further, the battery may also be used to power a communications module in case that the measured values shall be transmitted to a remote receiver. Consumption meters are usually left in place at the metering side for a long time, for example, several years or even more than a decade. During this time, the battery is never replaced. Thus, any battery serving as the power source in the consumption meter has to be highly reliable and have a low self-discharge. Certain battery types are particularly suitable for this kind of application. Preferably, the battery technology provides a high energy density and a low leakage current. One example type of such a battery is a lithium thionyl chloride (Li-SOCl2) battery. The disadvantage of these batteries is that the voltage supplied by the battery is not correlated with the remaining capacity as it is commonly known from batteries. Thus, contrary to conventional batteries it is not sufficient to measure the voltage across the battery to estimate the remaining capacity. In order to ensure that the consumption meters always remain operational, it is important that the meter's battery is exchanged in due time. Thus, accurately determining or estimating the remaining capacity or lifetime of the battery is important. Given that the battery is the only means of powering the meter, estimating the remaining battery capacity should be made with as little impact as possible on the battery runtime. JP 2021 179397 A discloses a battery life prediction system for lithium thionyl chloride batteries. The battery capacity is estimated based on a current consumption value which is calculated by summing up the product of the operating time of every operation and the current consumed per hour for that operation. Christopher Osterloh, et al. "Usage based low battery indication method and system", IP.COM, IP.COM.INC, West Henrietta, N.Y. discloses a method for determining the coulomb consumption and remaining coulomb capacity of a battery. The remaining capacity of the battery is calculated by subtracting the consumed coulomb over the battery life from the initial coulomb capacity. The coulomb consumption is determined by tracking the operation, the duration of an operation mode, and the temperature of the device. CN 113 447 830 A discloses a method for estimating the remaining battery capacity of a lithium battery. The capacity is estimated based on the current use for every working cycle which is multiplied by the number of times the working cycle is operated. Hence, it is an object of the present invention to provide a consumption meter as well as a consumption meter system comprising a consumption meter which enables accurately estimating the remaining battery lifetime of the battery used in the meter while keeping the overall battery consumption as low as possible. The problem underlying the present invention is solved by a consumption meter according to independent claim 1 as well as a consumption meter system according to claim 6. Preferred embodiments of the invention are described in the dependent claims. In a first aspect a consumption meter comprising a battery for energy supply and an accumulation module is provided. The accumulation module is configured for accumulating a first quantity over a time period to obtain a first accumulated quantity. The first accumulated quantity is based on a product of a current drawn from the battery and a duration over which the current was drawn from the battery. The accumulation module is further configured for transmitting the first accumulated quantity at regular or irregular intervals to a battery lifetime estimation module for calculating a remaining battery lifetime based on a nominal battery capacity, the received first accumulated quantity and an operating time of the battery. In other words, the consumption meter or short meter comprises at least a battery and an accumulation module. The battery supplies the energy required for operating the meter, e.g., for powering the metering circuitry and the accumulation module. The accumulation module is used to determine at least a first quantity representing a consumption