Battery Charger SoC Estimation to Skip Absorption Charging
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Solution Overview
Problem
Conventional battery chargers for utility vehicles frequently subject starter batteries to prolonged absorption charging modes, reducing their lifespan due to high charging voltage levels, leading to unnecessary water loss.
Innovation Solution
A method that estimates the battery's state of charge at the beginning of the bulk charging phase and decides whether to proceed directly to float charging mode or enter absorption charging mode, thereby optimizing charging time and extending battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery is frequently charged using conventional smart chargers that follow bulk-absorption-float charging modes, then the battery reaches full charge state, but the battery lifespan is reduced due to prolonged exposure to high charging voltage during absorption mode
Solution Approach 1:
The charging method dynamically adjusts the charging mode sequence based on the battery's state of charge at the beginning of bulk charging. When the initial state of charge is above a threshold, the system skips absorption mode and transitions directly from bulk to float charging. This dynamic adaptation prevents unnecessary exposure to high voltage during absorption mode, thereby extending battery lifespan while maintaining efficient charging when needed.
2Quantity of substance
If the battery is subjected to prolonged absorption charging mode with high charging voltage, then the battery reaches high state of charge (96-98%), but unnecessary water loss occurs in the battery
Solution Approach 1:
The method performs a preliminary assessment of the battery's state of charge at the beginning of bulk charging. Based on this preliminary information, it pre-determines the appropriate charging mode sequence. When the initial state of charge is sufficiently high, the system pre-arranges to skip absorption mode entirely, thereby preventing water loss before it can occur during prolonged high voltage charging.
3Reliability
If the charging mode is changed from conventional bulk-absorption-float to bulk-float sequence, then battery lifespan is extended by avoiding high voltage charging, but additional state of charge estimation is required
Solution Approach 1:
The charging system incorporates feedback from the battery's state of charge measurements taken during bulk charging. This feedback information is used to dynamically adjust the charging mode sequence. The state of charge threshold comparison provides a simple feedback mechanism that enables the bulk-float charging sequence decision without requiring complex control logic, thus extending battery lifespan while maintaining manageable system complexity.
Data Source
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AI summary
The present disclosure relates to a method performed by battery charger configured to charge a vehicle battery, the method comprising initiating, at a first point in time (t_Bulk_Start), charging of the battery in a bulk charging mode, determining, at a second point in time (t_Bulk_End) subsequent to the first point in time (t_Bulk_Start), that the charging of the battery in the bulk charging mode is completed, estimating, at the second point in time (t_Bulk_End), a state of charge of the battery at the first point in time (t_Bulk_Start) when the charging of the battery in a bulk charging mode was initiated, initiating charging of the battery in a subsequent charging mode using the estimated state of charge (SoC_Bulk_Start), wherein the subsequent charging mode is selected from an absorption charging mode and a float charging mode.