Battery pack with reduced magnetic field emission

Abstract

Implementations of a battery pack with reduced magnetic field emission are provided. The battery pack is configured to reduce or eliminate the magnetic field normally generated while electrical current is being drawn from cylindrical-steel electrochemical cells (e.g., AA batteries) by a connected electrical device. In some implementations, a battery pack with reduced magnetic field emission comprises two or more electrochemical cells positioned in a coaxial configuration. In this coaxial configuration, the supply path is through the center of each electrochemical cell, and the return path is through a conductive sleeve positioned about each electrochemical cell of the battery pack. In this way, the supply path and the return path are as close as is physically possible, thereby minimizing any magnetic field generated between the conductors (i.e., between the electrochemical cells and their conductive sleeves). An insulating layer of material separates each cylindrical-steel electrochemical cell from the conductive sleeve positioned thereabout.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This is a divisional application claiming the benefit of U.S. patent application Ser. No. 15 / 676,986, filed on Aug. 14, 2017, which claims the benefit of U.S. Provisional Application Ser. No. 62 / 449,727, which was filed on Jan. 24, 2017, both applications are incorporated herein by reference in their entirety.TECHNICAL FIELD[0002]This disclosure relates to implementations of a battery pack with reduced magnetic field emission.BACKGROUND[0003]In general, a magnetic field is generated when electrical current (or current) flows through a wire. Similarly, a magnetic field is generated when current is drawn from a battery by a connected device. If a wire having current flowing therethrough, or a battery having current drawn therefrom, is too close to a device that is sensitive to magnetic fields (e.g., an electronic compass—magnetometer), it will interfere with the proper function (e.g., orientation) of the device.[0004]As an example, the magne...

AI Technical Summary

Benefits of technology

The present patent text describes some ways to reduce the magnetic field generated by battery packs that use cylindrical-steel electrochemical cells. This can be done by minimizing or eliminating the loop area of the electrical conductors, which reduces the magnetic field generated by the battery pack. The patent also suggests a coaxial configuration with a thin layer of insulating material between the electrochemical cells to further minimize the magnetic field. Overall, this technology improves the performance and safety of battery packs by reducing the magnetic field and its related effects.

Problems solved by technology

If a wire having current flowing therethrough, or a battery having current drawn therefrom, is too close to a device that is sensitive to magnetic fields (e.g., an electronic compass—magnetometer), it will interfere with the proper function (e.g., orientation) of the device.

As an example, the magnetic fields generated by the flow of electrical current are a problem in the field of remotely piloted vehicles and unmanned aerial systems / drones (UAS).

As such, reliable autonomous flight is not possible if the electronic compass is unable to work properly due to magnetic interference.

Since a strong magnetic field is generated by the battery and wiring of an unmanned aerial system during operation, their dependence on an electronic compass is a major safety issue.

In this condition, due to the electronic compass being unable to provide accurate direction references, the flight controller attempts to achieve a position in space as instructed by the operator, or other system, but the sensors of the UAS cause it to “fly away” in a random direction.

The “fly away” condition is dangerous because the operator is no longer in control of the UAS and is therefor unable to keep it within the confines of a designated safe operating area.

Also, magnetic field interference is a leading cause of UAS crashes.

Thus, obtaining pouch cells with new chemistry typically requires a high volume purchase, the cost of which makes using pouch cells impractical for many applications.

This reduces the likelihood of a battery fire following the crash of a UAS.

The primary challenge with utilizing cylindrical-steel electrochemical cells in UAS applications is the presence of iron in the steel cylinder.

This magnetic field can cause an electronic compass (e.g., a magnetometer) to malfunction if it is positioned near the power source (i.e., one or more cylindrical steel electrochemical cells) of an UAS, making the use of cylindrical-steel electrochemical cells impractical on small / compact UAS.

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