Electricity: battery or capacitor charging or discharging – Serially connected batteries or cells – Switchable to parallel connection
Reexamination Certificate
2000-05-05
2001-07-31
Wong, Peter S. (Department: 2838)
Electricity: battery or capacitor charging or discharging
Serially connected batteries or cells
Switchable to parallel connection
C320S116000
Reexamination Certificate
active
06268711
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to a battery manager that provides for switching between batteries, battery cells, or other power sources and/or for switching them singly and/or series and/or parallel. This can be used to increase the runtime of electrical and electronic-based circuits being powered, to provide increased current drive, and/or to improve utilization of batteries in specialized applications.
BACKGROUND OF THE INVENTION
Presently, a battery management system is commonly provided for very complex electrical and electronic-based circuits or devices, such as laptop computers, which typically utilize rechargeable batteries. In these applications, the battery management system typically provides a specialized serial interface, such as the SMBus, for interfacing with an external controller such as a micro-controller. These battery management systems consist of specialized circuitry which is optimized for the unique chemistry of the specific battery type being monitored and controlled, i.e. nickel cadmium, lithium, etc. The battery management system and the associated microcontroller incorporate current or voltage level monitoring techniques to switch between battery sources and/or to shut down the device being powered at a battery discharge level that is controlled by data stored in memory. These battery management systems are of a greater complexity and cost than can be justified for less expensive devices.
SUMMARY OF THE INVENTION
This invention provides a simple (single/series/parallel) battery manager that can be utilized to monitor multiple battery power sources and to control the selection of the battery/power source(s). This is useful in extending the operational life of the device being powered or for enhancing the utilization of batteries in specialized applications. The single/serial/parallel battery manager performs required monitoring and switching functions without the need for microcontrollers, associated complex circuitry and programming unique to the battery chemistry, and/or the addition of specialized interfaces such as the SMBus. The invention relates to the electrical components, functionality, and interfaces required for managing the selection of the battery source(s) which provide power for the device, as well as control of the power source interfaces to the device. The invention provides for switching between individual battery sources for the extension of operating time of the system being powered through the incorporation of serial and/or parallel connection of batteries once the individual battery sources have degraded below a voltage or current threshold level. The invention also addresses the application of the simple single/series/parallel battery manager to improve utilization of batteries for specialized applications such as uninterruptible power systems (UPS) and control of electric motors.
Rechargeable or disposable power sources/batteries of any chemistry may be managed by this invention. These batteries may be utilized individually and in a series or parallel configuration to power the interfacing load device. Under initial operating circumstances, the battery manager selects one or multiple battery sources to power the interfacing device. Then, as the device's power requirements change and/or as the power capability of the battery/(ies) degrades, the battery manager switches from one power source configuration to another or to combinations of series or parallel, as required for the specific implementation.
Battery voltage level detector circuits (typically operational amplifiers (op amp)) monitor and compare the voltage level of the various batteries to a reference voltage (V
ref
). When the voltage of one or more batteries has degraded below the level of Vref, the voltage level detector provides output(s) to the FET control logic. These signals are processed by the FET control logic, causing the battery selection FET switching matrix to switch batteries in and/or out as the power source. Batteries will be switched alone or in combinations as determined by specific device implementation requirements. For instance, this could result in the output voltage being initially provided by battery
1
until battery
1
degrades to the level of Vref, then provided by battery
2
until it degrades to Vref, and then by battery
1
and battery
2
in series.
The battery manager may be enhanced with the addition of output power monitor circuits and/or DC/DC Converter. The output power monitor provides the means to monitor the load of the device being powered and to “feed” this information back to the battery manager for use in switching batteries in/out of the circuit upon demand. The addition of a DC/DC converter on the output provides the means to extend the output voltage beyond the limitations of standard off-the-shelf battery based power sources.
The simple battery manager is typically implemented with standard logic elements for control of switching characteristics, differential op amps for comparing voltage levels, and FETs to accomplish the actual switched arrangements.
REFERENCES:
patent: 5739596 (1998-04-01), Takizawa et al.
patent: 5969505 (1999-10-01), Okamuta
Brady W. James
Luk Lawrence
Mosby April M.
Telecky , Jr. Frederick J.
Texas Instruments Incorporated
LandOfFree
Battery manager does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Battery manager, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Battery manager will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2518967