from chemistry to pack
Every junction between two different metals in a sense-wire path is a small, unwanted thermocouple. If there’s a temperature difference across it, it generates a real voltage that a precision voltmeter cannot tell apart from the signal it’s supposed to be measuring. 1. A Junction You Didn’t Design Is Still a Junction Anywhere a copper … Read more
Capacity testing underpins virtually every other cell characterisation measurement. State of health calculations, degradation modelling, thermal management design, and pack-level energy budgets all trace back to a reliable baseline capacity figure. This page covers the standards that govern how that figure is established, the distinction between formation and lifecycle testing, the mathematics of capacity tracking, … Read more
A practical reference for sub-milliohm resistance testing in battery pack hardware: cell tab welds, busbar joints, contactor and relay contacts, and BMS current shunts. Cell tab-to-busbar welds, module interconnects, contactor and relay contacts, and BMS shunt resistors all sit in the same resistance band: tens of micro-ohms to a few milliohms. At this scale, a … Read more
Author: Arthur Claire, Sinovoltaics Factory acceptance testing is a structured verification process conducted at the manufacturer’s facility before a BESS is shipped to its installation site. The purpose is straightforward: confirm that the system meets the contractual specifications, performance requirements, and applicable safety standards before you take delivery. A comprehensive BESS factory acceptance testing program … Read more
If you are handling data from cell cyclers you will be aware of the different cell test data formats. The Problem Every cycler vendor has its own file format, its own column naming, its own unit conventions, and its own ideas about whether discharge current should be positive or negative. Maccor ships tab-delimited text with … Read more
If you want the best results in the laboratory it is really useful to learn from the experts: Solid state battery testing mould cleaning tips. Author: Anita Liu The Problem: Solid-state battery moulds are extremely sensitive to leftover powder, water stains, or surface scratches. Any of these can lead to poor electrode contact, low densification, … Read more
Author: Matthew Peter Jones Summary X-ray computed tomography (XCT) enables non-destructive, 3D visualization of lithium-ion (Li-ion) battery components and microstructure. At the cell level, XCT is especially useful for detecting manufacturing and quality issues in Li-ion cells [8]. However, turning XCT images into quantitative and reproducible quality assurance (QA) requires custom analysis pipelines that are … Read more
The Galvanostatic Intermittent Titration Technique or GITT as most know it in the world of battery chemistry and modelling as it is used to estimate diffusion coefficients, OCV, over-potentials and resistance. First described by Weppner and R. A. Huggins [5]. The GITT measures the transient voltage change and open circuit voltage (OCV) change during the charging … Read more
Where to start with the task of developing a lifecycle test procedure. Battery cell ageing is such a complex subject that it makes it difficult to know where to start. One of the first things to do is to break the problem into Calendar and Cycle Ageing. Now we know we are going to be … Read more
CompreCell Pouch x TekScan Sensor Author: rhd instruments GmbH & Co. KG Post based on an application note for which that and a full summary are now available: rhd-instruments.de magazine Introduction The pressure applied to pouch cell batteries is key to their performance and cycle life [1, 2, 3, 4]. One of two modes of … Read more