Patent application number | Description | Published |
20080304199 | Software-implemented overcurrent protection embedded in a battery pack - An overcurrent protection mechanism is provided for a battery pack that removably attaches to a power tool. The mechanism includes: one or more battery cells disposed in a battery pack; a current sensor configured to sense current supplied by the battery; a switch in a circuit path with the battery cells; and a battery control unit implemented as software instructions in a controller embedded in a battery pack. The battery control unit is configured to receive a signal indicative of current from the current sensor and control the switch to interrupt current flow from the battery cells as a function of current and time. | 12-11-2008 |
20080309285 | Battery pack identification system - A control module is included in a battery charger that is adapted to charge a plurality of battery packs of different types or a power tool that is adapted to be powered by at least one of the battery packs. The control module includes a remote sensing module that communicates remotely with one of the battery packs. The control module also includes a battery pack connection module that determines that the one of the battery packs is in electrical communication with at least one of the battery charger and the power tool. The control module also includes a battery pack identification (ID) module that determines a first type of the battery pack based on remote sensing module signals. The control module also includes a charge control module that determines at least one of a charge setting and a discharge setting for the battery pack based on the first type. | 12-18-2008 |
20090015206 | CELL MONITORING AND BALANCING - A method for monitoring the voltage of each of a plurality of cells of a battery pack is provided. The method may include monitoring a voltage potential for each of a plurality of cells in a battery pack utilizing a single channel of battery control unit within the battery pack. If, during discharge of the battery, e.g., the battery is being used to power a hand tool, the voltage potential of any cell is determined by the battery control unit to be below a predetermined minimum voltage, the battery control unit discontinues a current flow from battery pack to the tool. Additionally, during charging of the battery pack, if a voltage differential between any one of the cells and any other one of the cells is determined to be above a predetermined maximum differential, the battery control unit reduces the voltage potential stored in the cell having the higher voltage potential. | 01-15-2009 |
20090015208 | RESET MECHANISM FOR A BATTERY PACK - A battery pack may include a plurality of battery cells; a discharge switch in series with the battery cells, a temperature sensor configured to sense temperature in the battery pack, and a battery control unit adapted to receive a signal indicative of temperature from the temperature sensor and operable to control the switch to interrupt current flow from the battery cells when the temperature exceeds an over-temperature threshold. The battery control unit may be adapted to receive a reset signal and operable to control the switch to restore current flow upon receipt of the reset signal and when the temperature is below an operating temperature threshold. | 01-15-2009 |
20090096419 | BOTTOM BASED BALANCING IN LITHIUM ION SYSTEM - A method comprises discharging each of a plurality of cells of a battery pack, stopping the discharging of a selected cell of the plurality of cells when the selected cell reaches a predetermined capacity, and charging the plurality of cells after the discharging has stopped for all of the plurality of cells. | 04-16-2009 |
20090174563 | BATTERY IDENTIFICATION FOR BATTERY PACKS WITH INTER-CELL TAPS - A battery charger comprises a first electrical contact that receives a positive contact of an attached battery pack; a second electrical contact that receives a negative contact of the attached battery pack; a plurality of inter-cell electrical contacts that selectively receive inter-cell contacts of the attached battery pack; a measurement module; and a control module. The inter-cell contacts of the attached battery pack are connected to nodes between cells of the attached battery pack. | 07-09-2009 |
20090208819 | Rechargeable Battery Pack for Power Tools - A rechargeable battery pack comprises a battery having a high voltage side and a low voltage side, a positive terminal accessible external of the battery pack and connected to the high voltage side of the battery, a negative terminal accessible external of the battery pack and connected to the low voltage side of the battery, a control terminal accessible external of the battery pack, a switching element electrically connected between the control terminal and the high voltage side of the battery, and a control module operable to control the switching element so that the control terminal is selectively coupled to the high voltage side of the battery. | 08-20-2009 |
20100085012 | SIGNAL FOR PRE-CHARGE SELECTION IN LITHIUM CHARGING AND DISCHARGE CONTROL/PRE-CHARGE FUNCTION - A rechargeable battery pack for a power tool can have a data terminal that provides a signal that is indicative of whether the voltage is below a threshold and can serve as both a pre-charge signal for a charger and as a stop-discharge signal for a power tool. A charger can include a power supply circuit and a voltage detection circuit. A charger control module can receive a signal indicative of the voltage of the battery pack and determine a pre-charge time based on the voltage and can monitor a change in the voltage of the battery pack during the pre-charge operation and stop the pre-charge operation based on the change in voltage and the time period. | 04-08-2010 |
20100085018 | SHARED CONTROL OF THERMISTOR AND DUAL PURPOSE THERMISTOR LINE - A battery pack can include a temperature sensor that can provide an output that is indicative of a temperature associated with the battery pack. A battery management unit can directly measure the temperature sensor when the battery pack is by itself or engaged with a tool. A charger can directly read the temperature sensor when the battery pack is engaged with the charger. Thus, the temperature sensor can be shared by the battery pack and the charger. The battery pack can utilize a same terminal that provides access to the temperature sensor to indicate a stop-charge signal. The charger can read the stop-charge signal on the same terminal used to directly access the temperature sensor. | 04-08-2010 |
20100085021 | METHOD FOR STEPPING CURRENT OUTPUT BY A BATTERY CHARGER - A battery charger is provided for implementing a charging method having a stepped output current. The battery charger includes: a power supply circuit that receives an AC input signal and outputs a DC output signal. The power supply circuit includes a power supply controller configured to receive a feedback signal indicative of current being output by the power supply circuit via an amplifier and operates to control current output by the power supply circuit in accordance with the feedback signal. A charger controller is interfaced with the power supply controller to implement a charging method having a stepped output current. The charger controller may set the output current level by adjusting gain of an operational amplifier having a negative feedback configuration with the feedback signal input to a non-inverting input terminal of the operational amplifier, where the charger controller sets the output current level by changing the resistance at an inverting input terminal of the operational amplifier. | 04-08-2010 |
20120286732 | SHARED CONTROL OF THERMISTOR AND DUAL PURPOSE THERMISTOR LINE - A battery pack can include a temperature sensor that can provide an output that is indicative of a temperature associated with the battery pack. A battery management unit can directly measure the temperature sensor when the battery pack is by itself or engaged with a tool. A charger can directly read the temperature sensor when the battery pack is engaged with the charger. Thus, the temperature sensor can be shared by the battery pack and the charger. The battery pack can utilize a same terminal that provides access to the temperature sensor to indicate a stop-charge signal. The charger can read the stop-charge signal on the same terminal used to directly access the temperature sensor. | 11-15-2012 |
20130038293 | Cell Monitoring And Balancing - A method for monitoring the voltage of each of a plurality of cells of a battery pack is provided. The method may include monitoring a voltage potential for each of a plurality of cells in a battery pack utilizing a single channel of battery control unit within the battery pack. If, during discharge of the battery, e.g., the battery is being used to power a hand tool, the voltage potential of any cell is determined by the battery control unit to be below a predetermined minimum voltage, the battery control unit discontinues a current flow from battery pack to the tool. | 02-14-2013 |