Portable computers (or notebooks) typically include a single main battery that is charged and stores energy from an external alternating current to a direct current (AC/DC) adapter. Currently the main battery is a lithium ion battery and adds approximately one pound to the overall weight of the portable computer. The main battery degrades and may need to be replaced in one to five years. Degradation of the main battery may be due to use or due to failures in the cooling systems of the portable computer. Failures in the cooling system (e.g., a fan or heatsink) may be caused by collection of dust and debris, which will cause the entire portable computer to get hotter and hotter to the touch and for the cooling system to become louder over time.
The summary that follows describes some of the example embodiments included in this disclosure. The information is proffered to provide a fundamental level of comprehension of aspects of this disclosure.
An example embodiment of the present invention includes a portable computer and corresponding method. The portable computer may include at least one heat generating component and a battery cell thermally coupled to the at least one heat generating component. The heat generating component may be a processor, e.g., a central processing unit (CPU) chip or a graphics processing unit (GPU) chip, which may be thermally bonded to the battery cell. The battery cell may be a prismatic aluminum cell or a positive electrode. The battery cell may be oriented under the palm rest of the portable computer. The battery cell may have a heat capacity that is greater (e.g., at least an order of magnitude greater) than the heat capacity of the heat generating component. A thermal attachment block or heat pipe may be thermally coupled between the at least one heat generating component and the battery cell.
Another example embodiment of the present invention includes at least one radiating wall of the battery cell having an enhanced surface area with extruded heat sink/features (e.g., fins, pins, or the like). Additionally, the battery cell may be coupled to a cooling assembly, which may include a fan to direct airflow across the radiating wall of the battery cell. The battery cell may also be enclosed in a shield to protect the battery cell from direct heat radiation.
An example embodiment of the present invention may also include a motherboard of the portable computer and the battery cell may be coupled to the motherboard, for example, using a clip to allow for detachment.
A battery cell may be embedded within the motherboard of the computer in another example embodiment of the present invention. The battery cell may also be located on top of, within, or spanning the motherboard of the portable computer.
Another example embodiment of the present invention may include a plurality of cells within a battery cell pack housing and coupled to the at least one heat generating component. The cell pack housing may be located under the palm rest of the portable computer.
An example embodiment of the present invention may include charge management control that preferentially charges the battery cell during times when cooling is required.
Another example embodiment of the present invention may include additional portable computer components (e.g., hard disk, optical drive, etc.) that are enclosed in a shield and the shield is configured to protect the hard disk from direct heat radiation.
An example embodiment of the present invention may also include a plurality of cells distributed within a portable computer housing and each of the plurality of cells are individually, thermally coupled to the at least one heat generating component. The plurality of cells may be individually enclosed in a shield to protect from direct heat radiation. The plurality may also be coupled to a motherboard of the portable computer, for example using at least one clip to allow for detachment. The plurality may be comprised of prismatic aluminum cells and located under the palm rest of the portable computer.
Current notebook personal computers (or notebook PC) typically include an external battery that is enclosed in a plastic case and designs attempt to minimize heat transfer from the notebook to the battery pack because heat is known to degrade battery cells in their present form. Embodiments of the present invention may allow for battery cells to be embedded into the notebook PC design and for the embedded battery cells to act as a heat sinks if a means exists for transporting the heat out of the notebook PC. The battery cells may be adjacent to surfaces made out of material having high thermal conductivity, e.g., metal, engineered thermal materials, or the like. Using the embedded battery cells may minimize the amount and size of dedicated heat sinks, heat pipes, fans and other means of thermal management inside the notebook PC. The reduction of the need for both passive and active thermal management inside the notebook PC saves cost, space, and allows the manufacturer of the notebook PC to have more freedom in the overall designing process.
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
The present application is directed to a device comprising: at least one heat generating component and a battery cell thermally coupled to the at least one heat generating component. The device may be portable. The battery cell may be rechargeable, which includes lithium in a cathode of the battery.
Several configurations of the present invention for thermal management of a device using a battery are illustrated in
Another configuration shown in
The present application is also directed to a portable computer comprising at least one heat generating component and a battery cell thermally coupled to the at least one heat generating component. The heat generating component may be a processor (e.g., central processing unit chip or graphics processing unit chip), which may be thermally bonded to the battery cell. As used herein, “thermally bonded” means a pathway for thermal conduction, such as between a heat source and a battery that is better than what would occur in the absence of the pathway, while continuing to maintain electrical insulation between these same components. Examples include the use of thermally conductive epoxy, adhesive or electrical insulator film materials. Common terms for some such materials include “gap filler” and “gap pads” that describe the role of such materials to allow for efficient heat conduction between two components, such as a heat source and battery, without creating an electrically conducting path. This would allow taking advantage of the heat sink properties of the battery as described in this invention. Some examples of acceptable materials for thermal bonding include, but is not limited to, multiple Bergquist products, for example, Sil-Pad, Gad Pad, and Gap Filler brand name products, as well as multiple Emerson & Cuming products, such as, Stycast brand name epoxy. The battery cell may be a prismatic aluminum cell. The heat capacity of the battery cell is greater than the heat capacity of the heat generating component, such that the heat capacity of the battery cell is at least an order of magnitude greater than the heat capacity of the heat generating component. The portable computer may also include charge management control that preferentially charges the battery cell during times when cooling of the at least one heat generating component is required.
The battery cell may have at least one radiating wall, which includes an enhanced surface area. The radiating wall may include fins, pins, extruded features or the like. The battery cell may be coupled to a cooling assembly, which includes a fan to direct airflow across the radiating wall of the battery cell.
As shown in
Alternatively,
A portable computer may also include the motherboard of the portable computer and the battery cell may be coupled (e.g., using at least one clip) to the motherboard of the portable computer.
The ability of designers to place batteries on the printed circuit board provides additional design flexibility. For example, the battery cell may be detached from the motherboard; the battery cell may be embedded within or located on top of or spanning the motherboard of the portable computer; or the battery cell may be oriented under the palm rest of the portable computer. Employment of configurations, or features, that permit removal of battery 235 from printed circuit board 231, such as a compression clip 236, as shown in
In another approach, the battery may be thermally coupled 254 directly to the surface of a printed circuit board 251, as shown in
Distributed notebook battery cells may be mounted to the circuit board using techniques described in the descriptions of
The portable computer may also include plurality of cells distributed within the housing of the portable computer. The plurality of cells may be individually, thermally coupled to the at least one heat generating component. The plurality of cells may also be individually enclosed in a shield, which protects the plurality of cells from direct heat radiation. In addition, the plurality of cells may be coupled (e.g., using at least one clip) to a motherboard of the portable computer. The plurality of cells may also be detached from the motherboard. The plurality of cells may be comprised of prismatic aluminum cells. The plurality of cells may also be located under the palm rest of the portable computer. The portable computer may also include a thermal attachment block that is thermally coupled between the at least one heat generating component and the battery cell. The portable computer may also include a heat pipe thermally coupled between the at least one heat generating component and the battery cell.
Another placement, shown in
As illustrated by
As such, examples of suitable batteries for the present invention includes batteries having a high ratio of surface area to volume include batteries that have at least one relatively planar surface, such as prismatic battery cells, as illustrated by
In the embedded design, the can of the battery cell employed can be specially designed to have a larger, or enhanced, surface area for heat transfer. Two examples are shown, in
The present application is also directed to a method for using a battery cell to assist in heat transfer within a portable computer comprising thermally coupling at least one heat generating component of the portable computer to the at least one heat generating component. The battery cell may then be coupled to a cooling assembly. The cooling assembly may be used to direct airflow across at least one radiating wall of the battery cell, wherein the at least one radiating wall of the battery cell has an enhanced surface area. The battery cell may be enclosed in a shield that protects the battery cell from direct heat radiation. The battery cell may be coupled to the motherboard of the portable computer, wherein coupling the battery cell includes using at least one clip. The battery cell may also be detached from the motherboard. The method may further include for charging the battery cells (preferentially) when cooling is required.
The method may further comprise including the battery cell in a plurality of battery cells distributed within a portable computer housing and individually, thermally coupled to the at least one heat generating component. In addition, the method may also include maintaining the temperature difference between each battery cell to within a difference of at least less than 10° C. or at least be less than 2° C. The method may also allow for maintaining the capacity difference between each cell to within a difference of at least less than 60 mAH.
The method may further comprise individually enclosing the plurality of battery cells in a shield configured to protect a respective battery cell from direct heat radiation. The method may also include coupling the plurality of battery cells to a motherboard of the portable computer or configuring the plurality of cells for detachment. The method may further comprise regulating processing speeds of the portable computer based on the temperature of the at least one heat generating component.
In the embedded design, the battery charging process, which is an endothermic (heat absorbing) process, may be coordinated with by using a method to control the thermal management of the computer. To do so, an algorithm can be employed to optimize the charging process to coordinate with a major heat source inside a portable computer, for example CPU or GPU chips. An example for the algorithm is shown in
When the notebook computer is plugged in at 603 with an AC adaptor, the user may select 609 a charge profile either to charge the cells to a full charge (normal mode) 611, or allow a smart module to control the charge (charge cooling mode) at 613. Under the second alternative, when the electronics detect that the temperature of the CPU is over the pre-set limit (overheated) at 615, it will start the charging process at 619 to cool the CPU down by lowering the temperature of the battery (which operates at a lower temperature during charging). In addition, the module can also generate a buffer charging zone when the CPU temperature is low. In this case, the electronics switch to battery power until the state of charge (SOC) of the battery is below or equal to a pre-determined value (low voltage (LV) of SOC) even though the AC adaptor is plugged in, when it detects that the CPU temperature is low. In this way, the battery may be charged when it is needed to increase heat dissipation. The LV and high voltage (HV) may be set, for example, anywhere from 20% to 90% of SOC, preferably 40% to 80%.
If the AC adapter is not plugged in at 603, the portable computer is maintained in normal power mode 607. If the AC adapter is plugged in at 603, the user may select battery cooling at 609. If the user does not select battery cooling 609, the portable computer may be placed in normal charge mode 611. If the user selects battery cooling at 609, the algorithm may then approximate whether the SOC of the battery is greater than LV at 613, and the algorithm may approximate whether the CPU has overheated at 615. If the CPU has not overheated at 615, the portable computer may be powered at 617 using the battery until the LV of SOC has been reached. If the CPU has overheated at 615, the portable computer may be placed in normal power mode at 619. If the SOC is not greater than LV at 613, the portable computer may be placed in normal charge mode until LV of SOC has been reached at 621. The algorithm may then approximate if the CPU has overheated 623. If the CPU has not overheated at 623, the portable computer may be placed in normal power mode at 625. If the CPU has overheated at 623, the algorithm may decide to charge the battery to HV at 627, and the algorithm may repeat the approximation of whether the SOC is greater than LV at 613.
The portable computer may also include a plurality of cells contained within a battery cell pack housing and coupled to the at least one heat generating component.
The battery cell pack housing may be located under the palm rest of the portable computer.
In another embodiment, the invention includes battery pack 710, an exploded view of which is shown in
In still another embodiment of a battery pack 810, shown in
Another embodiment of a battery pack 910, shown in
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
Even though embodiments have been shown and described that involve CPUs and GPUs, it should be understood by one with ordinary skill in the art that additional embodiments are available.
It should also be understood that the flow diagram of
This application claims the benefit of U.S. Provisional Application No. 61/191,846, filed on Sep. 12, 2008, and U.S. Provisional Application No. 61/194,382, filed on Sep. 26, 2008 for Embedded Battery Cells and Thermal Management of Personal Computers by Per Onnerud, Phillip E. Partin, Scott Milne, Yanning Song, Richard V. Chamberlain, II, and Nick Cataldo, the teachings of both of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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61191846 | Sep 2008 | US | |
61194382 | Sep 2008 | US |