Battery Current Balancing Control for Uneven Discharge
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Solution Overview
Problem
In systems with multiple independent batteries powering interconnected loads, parasitic resistances and current variations cause one battery to discharge prematurely, leading to uneven aging and potential system shutdown.
Innovation Solution
A system with first and second sense circuits to monitor current from each battery, an input current controller to equalize the current provided by the batteries, and a buck boost converter to adjust voltage and ensure balanced discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple independent batteries are used to power interconnected loads, then the power supply capacity is increased, but current imbalance causes one battery to discharge prematurely leading to reduced reliability
Solution Approach 1:
The patent implements feedback control by monitoring the current output of each battery through sense circuits and using this information to dynamically adjust the current contribution of each battery via the input current controller. This closed-loop feedback mechanism ensures that batteries discharge at balanced rates, preventing premature exhaustion of any single battery while maintaining the increased power supply capacity provided by the multi-battery configuration.
2Power
If multiple independent batteries are used to power interconnected loads, then the power supply capacity is increased, but current imbalance causes one battery to reach cut off limit before another, leading to premature shutdown
Solution Approach 1:
The feedback control mechanism continuously monitors battery current output and adjusts each battery's contribution to maintain balanced discharge rates. This ensures that all batteries reach their cut-off limits simultaneously, maximizing the overall system runtime and preventing premature shutdown caused by one battery exhausting its charge before others.
3Power
If multiple independent batteries are used to power interconnected loads, then the power supply capacity is increased, but parasitic resistances and current variations cause uneven discharge, leading to accelerated aging of one battery
Solution Approach 1:
The feedback control system compensates for parasitic resistances and current variations by continuously monitoring actual battery output and dynamically adjusting each battery's current contribution. This active balancing prevents any single battery from being overworked or discharged at an accelerated rate, thereby equalizing the aging process across all batteries and extending overall battery system life while maintaining increased power capacity.
Data Source
AI summary
A system includes a first sense circuit configured to provide a first output representative of sensed current provided by a first battery coupled to a first load. A second sense circuit is configured to provide a second output representative of sensed current provided by a second battery coupled to the first load. An input current controller is coupled to receive the respective first and second outputs and to couple between the second battery and the first load to control the current provided by the second battery.