Dual Battery Charging Isolation Using Alternator Surplus Detection
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Solution Overview
Problem
Existing dual battery systems face challenges in efficiently charging an auxiliary battery without adversely affecting the primary battery, particularly due to incorrect timing in switching operations, which can lead to discharge of the primary battery and inability to start the vehicle's engine.
Innovation Solution
A dual battery system with a power supply circuit that detects a surplus condition, such as a voltage threshold, to supply current to recharge the auxiliary battery only when the alternator generates more power than needed for the primary battery, and immediately ceases this supply when the surplus condition is no longer met, ensuring the primary battery remains fully charged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single battery is used to power both the radio frequency (RF) circuit and the display device, then the device complexity is reduced, but the battery life is insufficient to support both functions simultaneously
Solution Approach 1:
The patent divides the single battery system into two separate batteries: a first battery dedicated to powering the RF circuit and a second battery dedicated to powering the display device. This segmentation allows each battery to be optimized for its specific function, with the first battery having higher energy density for continuous RF operation and the second battery having higher power density for display activation, thereby extending overall device operational duration.
2Ease of manufacture
If a single battery is used for both RF and display functions, then the manufacturing cost is lower, but the energy efficiency is insufficient
Solution Approach 1:
The patent applies local quality by selecting different battery chemistries optimized for specific functions: the first battery uses chemistry with higher energy density (e.g., lithium polymer) optimized for continuous low-power RF operation, while the second battery uses chemistry with higher power density (e.g., lithium-ion) optimized for high-power display activation. This localized optimization of battery properties for specific functions improves overall energy efficiency.
3Duration of action of moving object
If high energy density batteries are used to extend battery life, then the duration of action is improved, but the power output is insufficient for high-power functions
Solution Approach 1:
The patent segments the power delivery function by assigning the first battery (high energy density) to provide sustained power for continuous RF operation, while the second battery (high power density) provides burst power for high-power display activation. This segmentation allows the system to achieve both extended duration and high peak power output by drawing from the appropriate battery based on functional requirements.
Data Source
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AI summary
A dual battery system, including: a primary battery which drives a starter motor; an auxiliary battery which drives one or more auxiliary loads; an alternator which supplies current to recharge the primary battery; and a power supply circuit which supplies current from the alternator to recharge the auxiliary battery when a surplus condition is detected, the surplus condition indicating that the alternator is generating more electrical power than is required for recharging the primary battery, wherein the power supply circuit ceases to supply current to recharge the auxiliary battery when absence of the surplus condition is detected so that the primary and auxiliary batteries become electrically isolated, thereby ensuring that recharging of the auxiliary battery does not have an adverse effect on the level of charge of the primary battery.