Power Tool Battery Pack for High-Rate Charging and 4C Discharge
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Solution Overview
Problem
Battery packs for power tools, particularly in commercial garden tools, suffer from low output power and slow charging speeds, leading to prolonged energy waiting times and reduced working efficiency.
Innovation Solution
Development of high-capacity battery cells with charge rates greater than 5 C, internal resistance less than 3 milliohms, and energy density exceeding 120 Wh/kg, along with a mobile charging apparatus providing rapid charging and energy supply for multiple jobs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional battery packs are used in power tools, then the power tools can operate without fuel and exhaust emissions, but the output power is insufficient and charging speed is slow
Solution Approach 1:
The patent applies parameter changes by specifying precise electrical parameters for the battery cells: charge rate greater than 5C, internal resistance less than 3 milliohms, and capacity of at least 3.6 Ah. These parameter specifications transform conventional battery performance limitations into enhanced power delivery capability while maintaining environmental benefits of electric power tools.
2Object-generated harmful factors
If conventional battery packs are used in power tools, then the power tools can operate without fuel, but the charging speed is slow resulting in prolonged energy waiting time
Solution Approach 1:
The patent addresses charging time by specifying a charge rate greater than 5C, which enables rapid charging capability. This parameter change allows the battery pack to accept high charging currents, significantly reducing the time required to recharge between uses and minimizing energy waiting time while maintaining the environmental advantage of electric power tools.
3Speed
If high charge rate battery cells are used, then the charging speed increases, but the internal resistance may increase affecting power delivery
Solution Approach 1:
The patent resolves this contradiction by simultaneously specifying both charge rate greater than 5C and internal resistance less than 3 milliohms. This dual parameter specification ensures that the battery cells can accept rapid charging while maintaining low internal resistance for effective power delivery to the tool, achieving both fast charging and high power output capabilities.
4Use of energy by moving object
If battery cells with high capacity are used, then the energy density increases, but the charging time may increase
Solution Approach 1:
The patent balances energy density and charging time by specifying capacity of at least 3.6 Ah combined with charge rate greater than 5C. This parameter combination ensures sufficient energy density for extended operation while the high charge rate compensates for the larger capacity, maintaining acceptable charging times despite increased energy storage capability.
Data Source
AI summary
A battery pack includes a housing and at least one battery cell located within the housing, a charging and discharging port disposed on the housing, the charging and discharging port is provided with a connection terminal, the connection terminal is configured to be connected to the battery cell; the external device is configured to be connected to the battery cell through the charging and discharging port and configured to charge or obtain electrical energy from the battery cell; the battery pack is discharged at a continuous discharge rate of greater than or equal to 4 C at normal temperature, the absolute temperature of the battery pack is less than the charging protection temperature when the discharge process is completed.