Abstract: A system for monitoring energy consumption of an electrical appliance. The present invention provides an elegant means of monitoring energy consumption by legacy appliances such as a HVAC system. The energy consumption is monitored by the use of new and innovative wireless sensing device that is placed adjacent to or in contact with the appliance while it is operational. Appliance usage pattern information and power consumption information is communicated by the wireless sensing device and is collected by a gateway (and in some embodiments, an energy pump device, an intelligent power meter or a collector device). User behavior is modified by recommending approaches to cut energy consumption by the appliances thereby providing savings and reducing the cost of operation.

Abstract: Apparatus for monitoring the voltage of electricity supplied on a cable (121) are described. The apparatus includes a sense electrode housed in an electrically-insulative housing to form a capacitive coupling (127) between the sense electrode and the cable. The housing may be of the clamp-on type. A sense capacitor (128) of known capacitance is included, which is electrically coupled to the sense electrode and a local ground. Suitable voltage measurement circuitry (126) is connected to the sense capacitor and is responsive to voltage produced across the sense capacitor to provide an output signal representative of the voltage on the cable. The measured voltage waveform can be filtered to give the fundamental of the supply voltage, which can eliminate or reduce the effects of changes in capacitance within one cycle. A secondary capacitive (130) coupling can be formed with a related neutral wire (122) to improve stability of the voltage waveform measurement.

Abstract: A system and method for evaluating power usage, applicable to a power consumption environment provided among a power supplying device, a battery, and a power supplying network, are provided. The method includes: receiving, by a receiving module, information about power usage, information about characteristics of the power supplying device, information about characteristics of the battery, and information about characteristics of the power supplying network entered by a user; storing the above-mentioned information to a storing module by the receiving module; and analyzing or comparing the above-mentioned information by an evaluating module according to a preset rule or algorithm so as to calculate information about power consumption. The system and method are effective in analyzing, evaluating and optimizing power consumption behavior of users, thereby assisting users in deciding on the best power consumption mode according to the calculated information about power consumption.

Abstract: A method of identifying energy consumption associated with at least one appliance is provided. The method includes measuring an energy consumption signal, obtaining publicly available information of a location of the at least one appliance and estimating a plurality of probabilities of energized appliances based on the energy consumption signal and the publicly available information. The method further includes generating a new combination of the estimated plurality of probabilities of energized appliances and decomposing the at least one energy consumption signal into constituent individual loads and corresponding energy consumption.

Abstract: In one aspect, the present disclosure relates to a method to read energy-related data in a power meter. In one exemplary embodiment, the method includes the step of sending a request message to an on-premise processor, directing the on-premise processor to read energy-related data from a power meter, using an 802.11 X-based wireless protocol. The method further includes the step of retrieving energy-related data stored in a memory of the power meter by the on-premise processor, using the 802.11 X-based wireless protocol, and the step of receiving a response message sent at a host processor, communicated from the on-premise processor, using the 802.11 X wireless protocol. The method further includes the step of recording the energy related data in a data structure in memory of the host processor, along with a date and time information.

Abstract: Packet formats and associated metering infrastructure for filtering meter reading data that is being transmitted by utility meters are disclosed. In one embodiment, a method suitable for being implemented in a metering environment is provided that filters meter reading data being received by multiple collectors. Specifically, the method includes ranking the relative ability of the plurality of collectors to capture transmissions from the same utility meter. Based on the relative ranking, at least one collector from the plurality of collectors is identified that will be configured to disregard transmissions that originate from the utility meter. Then, the method provides the collector with a read list for differentiating between transmissions containing meter reading data that will be forwarded to a utility service provider from transmissions that originate from the utility meter.

Abstract: In a method for detecting anomalies in a sensor-networked environment, packages of data are received from a plurality of sensors located in the environment. At least one candidate problem location in the environment is identified based upon data contained in the packages. A principal components analysis is performed on the data collected from sensors associated with the identified at least one candidate problem location to identify a number of hidden variables and the number of hidden variables are analyzed to detect anomalies in the environment. In addition, detected anomalies are outputted. An analyzer for performing the method is provided.

Abstract: A monitoring system capable of being operationalized. Power consumption is electrical devices is monitored by the use of new and innovative consumption power monitoring device in accordance with the present invention. Power consumption information is collected by an intelligent power hub that is communicatively coupled to a remote server that presents overall power usage displays. A method of operationalizing a power usage monitoring system comprises powering up an energy pump device when the energy pump device is plugged into a first power socket, setting the energy pump device automatically to a SET mode to acquire new monitoring devices, and discovering the presence of a power consumption monitoring device.

Abstract: A system is provided that allows the aggregation of a plurality of inputs from an electrical grid and the display of the plurality of inputs on a single integrated display for a network operator. The system accepts signals from electrical loads and generation devices and analyzes the inputs to determine potential issues or trends, including fault predictions and recommends contingency plans. The system presents these potential issues and possible corrective actions to the network operator. The network operator may initiate actions, such as dispatching loads or activating generation capacity for example, in response.

Abstract: A system and method is provided for managing energy data. The system includes a energy transformation device, a central energy data management system and a database containing carbon dioxide credit information. Managing the energy data includes measuring an amount of power produced or consumed by an energy transformation device, measuring an amount of carbon dioxide emitted, converted or sequestered by the energy transformation device, creating a dataset of the power produced or consumed and the amount of carbon dioxide emitted or sequestered, and transmitting the dataset and characteristic data to a central energy data management system. The method also includes, receiving energy measurements and characteristic data from an energy transformation device, obtaining carbon dioxide credit information and comparing the received energy measurements and the characteristic data with the received carbon dioxide credit information to obtain a carbon dioxide credit for the energy transformation device.

Abstract: A communication and control system for a high voltage power line using an energy harvesting power supply to avoid batteries in the communication components maintained at line voltage. The energy harvesting power supply utilizes scavenged backscatter power received from a transceiver maintained at ground potential or a power supply with a super-saturating magnetic flux core, such as a mu-metal core, to harvest electromagnetic field energy from the power line. The communication equipment maintained at line voltage communicates information to the transceiver maintained at ground potential by modulating backscatter energy reflected from the beam transmitted by the ground level transceiver to minimize the power requirement of the communication equipment maintained at line voltage. Response equipment includes capacitors, voltage regulator, voltage sag supporter, circuit interrupter, remote communication equipment, reporting and analysis system.

Abstract: The present invention is a method and system for monitoring the continuous flow of power delivered by multiple DC Direct current operated starter motors used to start engine driven electrical generators. The method and system comprise the closing of a starter battery system and an associated starter control switch, causing the starter battery system to discharge through a shunt whereby current is fed into a starter motor. The shunt is optionally provided as a precision resistor with a pre-calibrated voltage drop in millivolts DC proportional to a current passing through it. The shunt directs current to a meter relay, which is calibrated by establishing two set points, or desired trigger ranges, for the meter relay. If the current falls outside a range established by the two set points, then a meter relay alarm output is activated; and, if the current remains within the range, then the meter relay alarm output is not activated.

Abstract: Embodiments of methods and apparatuses for collecting, analyzing, and transmitting real-time electron sources of an electrical grid are disclosed herein. In various embodiments, a computing device may be configured to collect data describing present generating source or sources for one or more present supplies of electricity to an electrical grid. Additionally, the computing device may be configured to analyze the data, and determine an amount of a present electricity flow on the electrical grid being generated from one or more renewable sources. Further, the computing device may be configured to generate and transmit a signal or message to one or more devices associated with consumption and/or storage of electricity supplied by the electrical grid, based at least in part on the result of said analysis and determination. Other embodiments may be described and claimed.

Abstract: A computer processor implemented method of determining system configuration information of a monitored electrical system without the need for user input by constructing a data set of a standard performance curve for at least one system type; defining at least one characteristic feature for each system type; determining the required data to identify at least one system type according to at least one of the standard performance curve and characteristic feature; remotely acquiring the required data; comparing system acquired electrical system data to at least one system type and correlated standard performance curves and correlated characteristic features to provide system configuration information for at least one monitored electrical system to provide the specific type of monitored electrical system.

Abstract: Apparatus and methods are provided for the measurement of power consumption at points of interest, such as circuit breakers, machines, and the like. Accordingly, means are provided for measurement of power consumption for each electrical sub-network that is controlled by a circuit breaker. Each apparatus is enabled to communicate its respective data, in an environment of a plurality of such apparatuses, to a management unit which is enabled to provide finer granularity power consumption profiles. Challenges of measuring relatively low supply currents, wireless operation in an environment of a large number of apparatuses, and self-powering are addressed.

Abstract: A novel load-reporting circuit breaker having load sensing and a wireless transmitter providing a corresponding load signal and an identification signal of the distribution panel(s) and circuit. A receiver common for several or all load-reporting circuit breakers provides a signal corresponding to the received individual circuit loads and corresponding identifications or address data, to an accounting device, e.g. computer that aggregates all loads for each user to which such load is allocated.

Abstract: The present invention is directed to a method of (1) providing continuous monitoring of various operating and environmental characteristics using RFID technology or similar wireless technology and (2) capturing data on historical events that have occurred on the circuits used for the transmission and distribution of electric power. The invention has the additional capability to communicate the information to operators at the site, in remote locations, or to other equipment (peer to peer). The invention provides a low cost method and apparatus to monitor and store operating characteristics and events on the electric power distribution circuit. The information can be used to reduce the duration of outages, for improving system reliability, to study the impact on the power grid of various environmental factors, to enhance the ability to react to operating conditions such as overloads, etc.

Abstract: A monitoring system for collection and distribution of power consumption information. It comprises a first monitoring device that is employed between, and electrically coupled to, a power socket and a first electrical appliance. The monitoring system also comprises a collector device that collects an energy consumption data from the first monitoring device and communicates it to a remote server. The collector device receives monitoring data from a number of electrical appliances with which it is communicatively coupled. Communication between the collector device that receives monitoring data from a number of electrical appliances and the monitoring devices occurs over a power line.

Abstract: In a wireless battery operated medical component (10), a battery life monitor, particularly a voltage monitor (16), takes voltage readings of a battery (12) to assess charge level as the battery (12) drains. The monitored charge level and medical data are transmitted (20) to a receiver (22) associated with a remote host unit (24). The host unit includes historical and typical battery level information and estimates remaining life of the battery (12). Battery life and medical information are displayed on a user interface (42). Typical battery operated medical components include EKG sensors, pulse sensors, blood oxygen sensors, blood measure sensors, brain wave sensors, temperature sensors, perfusion pumps, IV drip controllers, patient identification tags or wrist bands, pacemakers, respirators, x-ray detectors, and an MRI coils.

Abstract: A solar panel monitoring device and method is disclosed. The solar panel monitoring smart device comprises at least one power source or input; at least one sensor connected to the input, where the at least one sensor is adapted to responsively generate monitoring information on the input with which it is associated; a processor for receiving the monitoring information regarding the input from each of the sensors, and adapted to forward the received monitoring information; and a transmission chip for receiving the monitoring information, packetizing the monitoring information, and transmitting to a remote location.

Abstract: Information relating to electrical energy usage for a given account is associated with a time segment that corresponds to a period when the electrical energy was received from an electrical energy distribution system. Electrical energy generation carbon impact information is retrieved for the corresponding time segment specifying when the electrical energy was received from an electrical energy distribution system. A carbon credit is calculated according to the retrieved electrical energy generation carbon impact information, and the retrieved electrical energy usage information associated with the time segment. The calculated carbon credit is then used to update a display of carbon credit related information, such as account balance, rate of carbon credit usage, currently applicable “cost” for carbon credit usage. Notifications can be provided to the consumer if any of this information crosses a threshold value.

Abstract: Device and system for measuring the power consumption of individual power consumers in an office and the like. A simple device provides coupling to the respective consumer and sends the signal originating therefrom, with the aid of preferably ZigBee technology, to a central receiver, where it is processed. If appropriate, feedback is provided to the respective consumer. The central processing unit can not only be configured to provide information about the respective consumption to the consumer of the system but can also be programmed to display a comparison with the desired consumption. If appropriate, separate consumers can each be displayed. A circuit can be provided wherein the passage of power to one of the users is disconnected if a specific power consumption or the like is exceeded. It is also possible, for example for an energy company, to disconnect and connect a consumer which is coupled to the device remotely.

Abstract: A device is disclosed, in particular a power quality meter and power quality device, for determining and recording data relating to an electrical power supply system on the basis of analog electrical signals, in particular voltage, current and frequency, which are output and/or derived from the electrical power supply system and are passed to the inputs of the device. In at least one embodiment, the device includes a measurement channel, which is connected downstream from the inputs, for measuring the electrical signals, and a software-controlled processor, which is connected downstream from the measurement channel, for determining the data. In order to determine the quality of power supply systems with little effort, in at least one embodiment a communication channel is provided which has a communication interface which is likewise connected to the inputs and via which the device can communicate by cable via the electrical lines of the power supply system with correspondingly equipped other devices.

Abstract: A network device including: a power utilization monitor for monitoring and determining the power usage for the network device, the power usage being associated with a predetermined time value when the power usage was monitored; a data traffic monitor for determining the traffic flow of the network device, the traffic flow being associated with a predetermined time value when the traffic flow was measured; and a data correlator for correlating the power usage of the network device to the data traffic of the network device by associating the predetermined time value when the power usage was monitored with the predetermined time value when the data traffic flow measurement was made is described.

Abstract: Provided is an apparatus and method for customization of a protective device. The apparatus and method includes coupling programmer programmable memory to a microprocessor for processing select logic schemes. The programmer programmable memory is adapted to be modifiable by only a programmer of said protective device. Elements associated with some of the logic schemes are implemented into the programmer programmable memory in the form of a compiled settings structure having a plurality of allocation fields.

Abstract: A system for electric grid utilization and optimization, comprising a communications interface executing on a network-connected server and adapted to receive information from a plurality of iNodes, the plurality of iNodes comprising a source iNode, a sink iNode, and a plurality of transmission or distribution iNodes, an event database coupled to the communications interface and adapted to receive events from a plurality of iNodes via the communications interface, a modeling server coupled to the communications interface, and a statistics server coupled to the event database and the modeling server, wherein the modeling server, on receiving a request to establish an allocation of at least one of transmission losses, distribution losses, and ancillary services to a specific sink iNode, computes at least one virtual path for flow of electricity between a source iNode and the specific sink iNode and wherein the modeling server further computes, for each transmission or distribution iNode included in the computed

Abstract: A fractional smart metering system, comprising a processor coupled to a packet data network and a server software module executing on the processor and coupled to an operational database containing at least energy usage information pertaining to an energy consumer and obtained from meter readings at the consumer's premises, wherein the server software module is adapted to receive information over the network from a plurality of client software modules associated with energy resources further associated with the energy consumer, and wherein the server software module computes a measure of energy usage for a specific time interval for the consumer, said measure being determined at least in part based on a comparison between the information received from the client software modules associated with the consumer and the corresponding usage information obtained from the operational database, is disclosed.

Abstract: A resource monitoring system that includes at least one resource monitoring device. The resource monitoring device is integrated in, connected to and/or interconnected to at least one resource consuming device. A remote monitoring location can optionally be provided to receive information from one or more resource monitoring device and to provide information concerning and/or related to at least one resource consuming device.

Abstract: A system to monitor power loading in a plurality of power distribution units. The system includes a power monitoring gateway with a port configured to communicate with an internet protocol network using an internet protocol address. The power monitoring gateway is also configured to communicate with the plurality of power distribution units through a communication link that does not use internet protocol addressing. The communication link in some embodiments is a wireless link. In other embodiments, the communication link uses a single pair of wires with the power monitoring gateway and the power distribution units configured in a daisy chain topology.

Abstract: The present invention relates to an apparatus, a system and a method of user-assisted resource usage determination in a domestic setting, the method comprising defining a resource consuming user activity by the user by means of a resource consuming user activity identifier; defining an interval for metering resource usage; determining the resource usage during the defined interval; and storing the determined resource usage, the defined 5 interval and the association thereof with the resource consuming user activity identifier.

Abstract: A distributed generation power system includes a utility meter connectable to an electric utility provider and configured to communicate with a communication device of the utility provider, an inverter configured to convert distributed generation (DG) power generated by a DG power source into AC power, and an intermediate connector configured to connect the meter and inverter to constitute an integrated inverter-meter. The integrated inverter-meter is configured to communicate a measured aggregate amount of the DG power and a measured amount of power consumed on site to the communication device of the utility provider. The inverter is configured to receive at least one operating command from the meter and/or the communication device of the utility provider.

Abstract: A plurality of modules interact to form an adaptive network in which each module transmits and receives data signals indicative of proximity of objects. A central computer accumulates the data produced or received and relayed by each module for analyzing proximity responses to transmit through the adaptive network control signals to a selectively-addressed module to respond to computer analyzes of the data accumulated from modules forming the adaptive network. Interactions of local processors in modules that sense an intrusion determine the location and path of movements of the intruding object and control cameras in the modules to retrieve video images of the intruding object. Multiple operational frequencies in adaptive networks permit expansions by additional networks that each operate at separate radio frequencies to avoid overlapping interaction. Additional modules may be introduced into operating networks without knowing the operating frequency at the time of introduction.

Abstract: An exemplary embodiment includes a wind turbine system. The wind turbine system includes a wind turbine generator operable to supply wind turbine power to a utility system. A converter is coupled to the wind turbine generator and the utility system. The wind turbine system also includes a controller comprising an internal reference frame of the wind turbine generator, coupled to the converter, and configured for modulating flow of power through the converter in response to frequency disturbances or power swings of the utility system relative to the internal reference frame.

Abstract: A method and apparatus that uses the Internet protocol, TCP/IP, for a home control network. The apparatus also provides embedded servers, email clients at the electrical boxes. The apparatus integrates the Internet to the electrical outlet, switch or appliance boxes using a low cost embedded web server.

Abstract: A method and system for monitoring the operation of a wind energy installation. State data relating to the wind energy installation is recorded and discrepancies are found between the state data and an associated comparison value. A failure probability of the wind energy installation is determined based on any found discrepancy. An availability value for the wind energy installation is determined from the ratio of the actually produced amount of electrical energy to the total amount of energy which can potentially be produced. The availability value and the failure probability are then combined to form a repair priority, which is associated with the wind energy installation. Accordingly, more uniform operation of wind energy installations can be achieved.

Abstract: A panel meter including an energy test pulse device that enables the panel meter to be used for revenue applications and eliminates the need for two separate meters, one for panel indication, and the other for energy and revenue applications. The electrical panel meter including at least one sensor configured for measuring an electrical parameter; at least one analog-to-digital converter coupled to the at least one sensor for converting the measured electrical parameter to a digital signal; a display for continuously displaying at least one electrical parameter; a processor configured to receive the digital signal and calculate an amount of energy consumed; and a test pulse circuit configured to receive the calculated amount and generate a plurality of pulses equal to the calculated amount, wherein each of the plurality of pulses is equal to a predetermined amount of energy.

Abstract: A simulation system includes a simulation computer having a Web server and a client computer with an Internet browser. On the simulation computer, a process engineering process model of a technical plant is available, to which access can be made by the client computer via the Internet. In preferred embodiments, the simulation computer additionally includes an automation engineering process model of the technical plant, operation and observation software and a project engineering tool for changing the aforementioned programs in the simulation computer.

Abstract: A voltmeter/phaser includes dual hot-stick probes, each carrying a housing including a digital display, one of the housings also having a measurement circuit for measuring the sensed voltage. A plural-conductor cable interconnects the housings and carries, in two separate conductors, current between the probes and display data between the display circuits, so that identical voltage values are always displayed on the two displays.

Abstract: A method and system for monitoring and controlling a power distribution system is provided. The system includes a plurality of circuit breakers and a plurality of node electronic units. Each node electronic unit is mounted remotely from an associated circuit breaker that is electrically coupled with one of the node electronic units. The system also includes a first digital network, and a first central control unit. The first central control unit and the plurality of node electronic units are communicatively coupled to the first digital network. The method includes receiving digital signals from each node electronic unit at the central control unit, determining an operational state of the power distribution system from the digital signal, and transmitting digital signals to the plurality of node electronic units such that the circuit breakers are operable from the first central control unit.

Abstract: Methods and systems of managing node migration in a wireless network where nodes may spontaneously migrate from a first communication path to a second communication path. The system includes a first collector disposed within the first communication path and a second collector disposed within the second communication path, a network management server that determines a network state and maintains a database of the network state. When the network management server detects that a node has migrated from the first communication path to the second communication path, information associated with the node is retrieved from the first collector and downloaded to the second collector to ensure the proper operation of the node in the network.

Abstract: A method for processing meter data into a common format includes receiving, in a first transmission, meter data using a satellite communications network in a common protocol, the meter data representing information read at time intervals from associated utility meters in at least two data formats, each data format associated with a type of utility meter. The meter data in the plurality of formats is processed into a common data format. The meter data is stored in the common format as interval data for transmission to a customer.

Abstract: A method, via a processor, of forecasting energy usage including selecting a plurality of reference days with at least one feature matching a corresponding feature of a day to be forecasted and filtering the plurality of reference days with a humidity filter to identify at least one matching reference day. The at least one matching reference day is associated with a correlation coefficient greater than or equal to a minimum correlation coefficient, and a minimum number of humidity values within a range of corresponding humidity values of the day to be forecasted. The method also includes retrieving energy load values and corresponding temperature values corresponding to the at least one matching reference day, calculating a plurality of regression coefficients of a polynomial equation linking the temperature values to the energy load values, and calculating and storing a forecasted load value of the day to be forecasted according to the polynomial equation.

Abstract: An intelligent electronic device (IED) integrating a power metering unit (PMU) and a merging unit that combines signals from both analog transformers and digital transformers into a set of merged digital samples. Analog current/voltage signals from analog CTs/PTs are received at the IED's analog inputs and converted to digitized samples. Digital current/voltage samples from digital CTs/PTs are received via point-to-point connections at digital inputs of the IED. A tagging unit applies metadata tags to the digitized and digital samples. The metadata tags include the transformer providing the input signal, sampling rate, primary and/or secondary timestamps, scaling values, calibration values, and/or the location of the IED in the electrical system. The PMU performs metering and/or power quality calculations on the samples, and the calculation results are formatted and transmitted via a master-slave protocol to a requesting master.

Abstract: The method is providing an energy saving service. Customers of a household participate in an energy saving service provided by a service provider. The household prepays an amount for energy consumption in a subsequent time period. The customers determine at an end of a time period whether actual energy consumption during the time period is less than a reference energy-consumption. The household is rewarded with service points corresponding to a difference between the actual energy consumption and the reference energy consumption.

Abstract: Systems and methods for assessing and optimizing energy use and environmental impact can be designed to receive energy consumption and emission data from one or more energy consumption sources of a facility over a network. The data can be transformed into a database format that can be processed and analyzed. The data can be validated according to predefined validation rules. The data can be aggregated according to predefined time intervals and stored in memory. The data can be used to generate a report to a user, for example, via a user interface.

Abstract: A power management architecture for an electrical power distribution system, or portion thereof, is disclosed. The architecture includes multiple intelligent electronic devices (“IED's”) distributed throughout the power distribution system to manage the flow and consumption of power from the system using real time communications. Power management application software and/or hardware components operate on the IED's and the back-end servers and inter-operate via the network to implement a power management application. The architecture provides a scalable and cost effective framework of hardware and software upon which such power management applications can operate to manage the distribution and consumption of electrical power by one or more utilities/suppliers and/or customers which provide and utilize the power distribution system.

Abstract: A cable fault detection component (168) receives input data indicative of a fault in an electrical power system. The component (168) analyzes the input data to determine if the fault is indicative of a temporary or self-clearing cable fault and generates corresponding output data (276). In one implementation, the cable fault detection component (168) is implemented as a software module which operates on a computer (105) of a substation intelligence system (104).

Abstract: A power monitoring system for monitoring characteristics of power transmitted through one or more power lines comprises a meter base and multiple option modules. The meter base includes a processor and associated circuitry for processing signals derived from sensors coupled to said power lines and producing output signals representing selected characteristics of the power transmitted through the power lines, and a housing containing the processor and the associated circuitry and having a first surface adapted to be mounted on a DIN rail, and a second surface containing multiple connectors for receiving multiple modules and electrically connecting the modules to the processor and the associated circuitry.

Abstract: A system for managing consumption of power supplied by an electric utility to power consuming devices includes at least one client device and a server. Each client device operates at least partially responsive to control messages received from the server and controls operation of one or more controllable devices. Each controllable device selectively enables and disables a flow of power to one or more of the consuming devices. The server stores information, on a per client device basis, relating to power consumed by the consuming devices. When a power reduction is requested by the utility, the server selects, based on client device information stored in the database, at least one client device to which to issue a power reduction message that indicates at least one of an amount of power to be reduced and an identification of a controllable device to be instructed to disable a flow of power.

Abstract: A system and method of monitoring the amount of charge consumed from a battery powering a device, e.g., an implantable medical device, operable in at least first and second current drain states are disclosed. In each drain state, a current-sensing resistance correlated to the drain state is connected with the battery to develop a respective current drain state voltage that is converted to a current drain state count established over the duration of the drain state. The first and second current drain state counts are accumulated as cumulative first and second current drain state counts that are indicative of the amount of charge consumed from the battery. A battery charge state may be estimated from the cumulative first current drain state count and the first current state resistance and the cumulative second current drain state count and second current state resistance.