Battery Charge Control for Climate Controllers
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Solution Overview
Problem
Rechargeable lithium-ion batteries in climate control system controllers have a limited number of recharge cycles, and existing charging methods do not effectively prolong battery life by maintaining the battery at optimal voltage levels.
Innovation Solution
A controller with a charging circuit and power stealing circuit that monitors and adjusts the charge current and voltage to keep the battery within a specific range, limiting the charge current to trickle levels and maintaining the voltage between the top charge voltage and discharge end voltage, thereby extending battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional charging methods are used to charge the battery to full capacity, then the battery stores maximum energy, but the battery life is significantly reduced due to excessive voltage stress and rapid degradation
Solution Approach 1:
The patent changes the charging voltage parameter from the traditional full capacity voltage (e.g., 4.2V) to a reduced voltage level (e.g., 3.8V-4.0V). This parameter change allows the battery to maintain sufficient energy storage while significantly reducing voltage stress and extending battery life by 2-10 times compared to traditional charging methods.
Solution Approach 2:
The patent applies partial charging action by intentionally not charging the battery to full capacity. The charger limits the charge to a predetermined voltage level that is less than the maximum capacity voltage, providing sufficient energy for operation while avoiding the degradation caused by full charging. This partial action achieves the goal of extending battery life.
2Quantity of substance
If the battery is charged to full capacity frequently, then the energy availability is maximized, but the number of recharge cycles is limited
Solution Approach 1:
The patent changes the charge capacity parameter by establishing a predetermined voltage threshold below the maximum capacity voltage. The battery is charged to this reduced voltage level rather than full capacity, which maintains adequate charge quantity for device operation while dramatically increasing the number of recharge cycles the battery can endure.
Solution Approach 2:
The patent treats the battery charge cycles as expendable resources by accepting that each charge-discharge cycle at reduced voltage extends the overall lifespan. The system optimizes for total operational duration rather than maximum charge capacity per cycle, effectively making each cycle more sustainable.
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 method significantly prolongs the battery life by minimizing the rate of voltage change and optimizing the charge current, potentially increasing the number of recharge cycles by 2 to 10 times compared to traditional charging methods.
Implementation Method 1
A variable resistance is provided to selectively limit the charge current
Data Source
AI summary
Disclosed are exemplary embodiments of controllers and methods for use in climate control systems. In an exemplary embodiment, a controller for use in a climate control system includes a charger for providing a charge current to a battery of the controller. The controller also includes a variable resistance for selectively limiting the charge current. A control is configured to monitor the charge current and a voltage of the battery. Based on the monitoring, the control varies the resistance to keep the monitored voltage in a range defined by (a) a top charge voltage less than full capacity of the battery and (b) a discharge end voltage greater than a cut-off voltage of the battery. The monitored voltage has a substantially minimized rate of change within the range.