Abstract: A battery, usable with one or more battery support units and/or electronic devices, contains a memory which contains a mailbox. The battery receives a request from a battery support unit or an electronic device to write error data in the mailbox. In response to this request, the battery stores the error data in the mailbox. The battery then receives a request from a battery support unit or electronic device to read the error data from the mailbox. In response to this request, the battery transmits the error data to the battery support unit or electronic device that requested it.

Abstract: A battery support unit, such as a defibrillator battery charger, tests a battery having a memory for an error condition. If the battery support unit finds an error condition with the battery, it transmits error data to a mailbox located in the battery's memory. Other battery support units or electronic devices, or even this battery support unit at a later date, can read the error data in the mailbox and take an appropriate action. For example, the battery support unit can read the mailbox and, if it finds error data placed there by itself, another battery support unit, or an electronic device, enable an indicator, such as an indicator that informs a user that maintenance needs to be performed on the battery. When battery maintenance has been selected, the battery support unit reconditions the battery by charging and discharging the battery a predetermined number of times, and also performs additional testing on the battery.

Abstract: An electronic device, such as a defibrillator/heart monitor, monitors a battery having a memory for an error condition while the battery is operating the device. If the electronic device finds an error condition with the battery, it transmits error data to a mailbox located in the battery's memory. Other electronic devices or battery support units, or even this electronic device at a later date, can read the error data in the mailbox and take an appropriate action. For example, the electronic device can read the mailbox and, if it finds error data placed there by itself, another electronic device, or a battery support unit, enables an indicator, such as an indicator that informs a user that maintenance needs to be performed on the battery.

Abstract: An intelligent battery having an advance low battery warning for a battery powered device is provided. The intelligent battery comprises a battery suitable for powering a battery powered device and a charge monitor circuit. The charge monitor circuit continuously measures the amount of electrical charge input and output from the battery. When the amount of charge remaining in the battery goes below a threshold amount, an advance low battery warning is generated, wherein the charge remaining in the battery is calculated by subtracting the amount of electrical charge output from the battery from the amount of electrical charge input into the battery. The low battery warning occurs independently of the output voltage of the battery such that an advance low battery warning may be provided for a battery that maintains a substantially constant output voltage until just prior to complete discharge.

Abstract: A system having a battery, a battery support unit, and an electronic device provides for the exchange of information between the battery support unit and the electronic device via a mailbox in memory in the battery. When the battery is placed in the battery support unit, the battery support unit tests the battery for an error condition. If the battery support unit finds an error condition with the battery, it transmits error data to a mailbox located in the battery's memory. When the battery is then removed from the battery support unit and placed in an electronic device, the electronic device can read the error data in the mailbox and take an appropriate action. For example, the electronic device reads the mailbox and find the error data placed there by the battery support unit. In response to finding this error data, the electronic device enables an indicator, such as an indicator that informs a user that maintenance needs to be performed on the battery.

Abstract: A method and apparatus is disclosed for providing to the body of a patient a defibrillation pulse having a magnitude calculated to induce in that particular patient a desired defibrillation current. The patient's response to a defibrillation pulse is characterized in advance of defibrillation by repeatedly sampling the patient's transthoracic impedance to a small alternating current excitation signal. The sample having the lowest magnitude is taken to represent the patient's true transthoracic impedance. This lowest sampled impedance value is normalized to take into account the shape of the expected waveform and is then multiplied by the desired current to yield the target charge level to which an energy storage device must be charged to induce the desired current to flow in the patient on discharge. Charging of the energy storage device desirably begins before measurement of transthoracic impedance is completed and continues until the target charge is reached.