Abstract: A resistor ladder comprising identical resistors is disposed electrically in parallel with a multicell battery to calibrate voltage-controlled oscillators (VOCs) or analog-to-digital convertors (ADCs) for voltage balancing the battery cells in the multicell battery. Switches in a first state provide the voltage across each resistor as inputs to the VCOs or ADCs. The number of oscillations of the output signal of each VCO or ADC over a predetermined time period are compared to determine an offset error. Switches in a second state provide the voltage across each battery cell as inputs to the VCOs or ADCs. The battery cells with a higher relative voltage can be discharged until they are balanced. Some aspects describe temperature-adjusted and interpolated determinations of electrical quantities in the cells such as voltage and/or current.

Abstract: A method for controlling a charge to a battery pack via a battery management system (BMS) integrated circuit (IC) includes monitoring one or more parameters associated with the battery pack. The method also includes monitoring a charge output from a direct current (DC)-DC converter to the battery pack. The method further includes adjusting feedback to the DC-DC converter in accordance with monitoring the one or more parameters and monitoring the charge output, the feedback being a local feedback to the DC-DC converter or a reference input to the DC-DC converter.

Abstract: Disclosed are stereo sound system devices and methods for reproducing stereo sound with improved auditory experience and reduced speaker rattle. In some embodiments, the disclosed arrangement of speakers on the sound system housing and driving low frequency speakers with the same signal contribute to the improved auditory experience and reduced speaker rattle effect.

Abstract: Disclosed are stereo sound system devices and methods for reproducing stereo sound with improved auditory experience and reduced speaker rattle. In some embodiments, the disclosed arrangement of speakers on the sound system housing and driving low frequency speakers with the same signal contribute to the improved auditory experience and reduced speaker rattle effect.

Abstract: Disclosed are portable energy storage devices and methods for fast charging them using non-isolated power supplies, while maintaining device and user safety. Techniques are disclosed to reduce the size of power supplies needed to charge portable energy storage devices and reduce the charge time of these devices.