Charge Pump Battery Charging for Dead Multi-Cell Packs
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Solution Overview
Problem
Existing battery charging systems face inefficiencies and potential damage when attempting to fast charge a dead multi-cell-in-series battery, particularly due to high current demands that can shorten battery life.
Innovation Solution
A battery charging circuit utilizing a charge pump with an arbiter to select between multiple power supply nodes, including a third voltage source for powering the driver circuit, eliminating the need for a trickle charger and battery switch, allowing for efficient trickle charging of a dead multi-cell battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional battery charging system with trickle charger and battery switch is used, then the battery can be charged, but the area consumption and circuit complexity increase
Solution Approach 1:
The patent combines the functions of the battery switch and trickle charger into the charge pump circuit itself. The charge pump circuit directly controls the charging current and voltage without requiring separate switch and trickle charger components, thereby reducing circuit complexity while maintaining reliable battery charging capability.
Solution Approach 2:
The charge pump circuit is designed to perform multiple functions: it acts as both the main charging circuit and the trickle charger, and also functions as the battery switch through its control logic. This multi-functionality eliminates the need for separate dedicated components, reducing overall device complexity.
2Reliability
If a conventional battery charging system with trickle charger and battery switch is used, then the battery can be charged, but the power loss increases
Solution Approach 1:
By merging the switch and trickle charger functions into the charge pump circuit, the patent eliminates redundant power conversion stages and reduces the number of active components that dissipate power. The integrated design minimizes resistive losses and improves overall power efficiency during battery charging.
3Productivity
If fast charging is applied to a dead multi-cell-in-series battery, then the charging speed increases, but the battery may be damaged due to high current demands
Solution Approach 1:
The charge pump circuit dynamically adjusts its operating parameters based on the battery's charge state. When the battery is dead or at low voltage, the circuit operates in trickle charging mode with limited current to prevent damage. As the battery voltage increases, the circuit transitions to faster charging modes, optimizing charging speed while protecting the battery throughout the charging process.
Solution Approach 2:
The patent changes the operating parameters of the charging circuit based on battery conditions. The charge pump circuit monitors battery voltage and adjusts the charging current accordingly, transitioning from low-current trickle charging for dead batteries to higher-current fast charging as the battery recovers, thereby preventing damage while maximizing charging efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces area consumption, power loss, and complexity by eliminating the battery switch and trickle charger, providing a simpler and more efficient trickle charging process for multi-cell batteries.
Implementation Method 1
a charge pump circuit (206) comprising a plurality of switches and a capacitive element, being coupled to a first power supply node and a second power supply node, and being configured to at least one of: multiply a first voltage at the first power supply node to generate a second voltage at the second power supply node; or divide the second voltage at the second power supply node to generate the first voltage at the first power supply node
Data Source
AI summary
Methods and apparatus for trickle charging and precharging a dead multi-cell-in-series battery. One battery charging circuit generally includes a charge pump circuit comprising a plurality of switches, being coupled to first and second power supply nodes, and being configured to multiply (or divide) a first voltage at the first power supply node to generate a second voltage at the second power supply node; a driver circuit configured to drive the plurality of switches in the charge pump circuit; and an arbiter having a first input coupled to the first power supply node, a second input coupled to the second power supply node, a third input coupled to a third power supply node having a third voltage, and an output coupled to a power supply terminal of the driver circuit. The arbiter is configured to select between the first, second, and third voltages to power the driver circuit.