Battery Production
Introduction
Battery production requires very dry conditions to ensure product quality, maximise battery performance, and maintain safe manufacturing processes. Moisture can react with battery electrolytes, affecting product quality and creating possible safety risks. For this reason, battery manufacturing areas typically operate at dew points of -40 °C or lower, with some drying systems reaching -70 °C dew/frost point (approximately 1 ppmv water).
The Dangers of Moisture Ingress
Reliable moisture measurement is essential throughout the production process to ensure consistent product quality. The smallest level of moisture ingress can cause downstream product issues including:
- Capacity loss, where active lithium ions are permanently consumed by side reactions, lowering total energy storage
- Reduced power output and charging speeds caused by damage to internal paths
- Malfunction caused by debris and crystal deposits creating short circuits
Overcoming Drift in Humidity-Moisture Measurement
Maintaining dry conditions requires accurate measurement and control using dew point sensors, hygrometers, moisture analysers, dryers, and dehumidification systems.
The problem is that operating conditions and normal ageing can cause dew point sensors to gradually drift over time. Regular calibration is therefore essential to maintain measurement accuracy and ensure traceable results, but if drift occurs between scheduled calibrations, whole production runs can be compromised.
What’s the solution?
The FPG, the world’s first transportable dew-frost point calibrator, provides a portable, self-contained calibration system that enables dew point sensors, hygrometers, and moisture analysers to be calibrated on-site without removing them from service, whenever a potential issue arises.
Investing in an on-site FPG can:
- Reduce calibration costs by eliminating exchange and replacement programmes
- Minimise engineering time, transport costs, and inventory requirements
- Allow calibration without disconnecting the instrument from systems
- Enable complete system verification, including the measurement and control loops
- Support continuous calibration traceability to meet ISO 9001 and other quality management requirements.
FPG Universal Compatibility
Dew point sensors are available in many thread sizes, probe lengths, and connection types. The FPG has been designed to accommodate virtually all common instruments using interchangeable FPG-PA probe adapters.
For dew point chilled mirror hygrometers and moisture analysers, the rear-panel sample loop allows instruments to be connected using external sample tubing.
Calibration Procedure with the FPG
- Apply the correct FPG-PA probe adapter and install the instrument under test (IUT)
- Check that the system is leak-free using the procedure described in the user manual
- Set the first (lowest) dew/frost point and allow the system to stabilise
- Record the reading and repeat the process for each calibration point
- The initial results provide the As Found calibration data
- If adjustment is required, follow the manufacturer’s procedure and repeat the calibration to produce As Left results
- Generate a calibration report or certificate manually or using FPG Metrology calibration software.
Calibration Profile
The graph shows a typical calibration profile based on actual test data, comparing the FPG reference with a chilled mirror hygrometer and the instrument under test (IUT).
