from chemistry to pack
A Closer Look at SoC in Theory and Practice State of Charge (SoC) is one of the most used metrics in battery engineering, but also one of the most inconsistently defined. SoC is often described as the percentage of charge remaining in a battery, but what that percentage refers to depends heavily on how the … Read more
How do different battery chemistries compare in terms of calendar ageing? When we look at battery lifetime the standard method used by industry has two fundamental test regimes as inputs: Here we are focussing on the Calendar Ageing, this is all about how the cell ages just left on a shelf doing nothing. Dubarry et … Read more
When sizing a battery pack one of the first things to look at is the number of cells in series and pack voltage. Pack Nominal Voltage = Cell Nominal Voltage x Number of Cells in Series Cells in Series When connecting cells in series the negative terminal of the first cell is connected to the … Read more
Enhancing Lithium-Ion Battery Management with Advanced Kalman Filter Tuning summarises the work conducted by Jasper Knox, Mark Blyth and Alastair Hales (all University of Bristol). Lithium-ion batteries are integral to modern electric vehicle development, requiring advanced battery management systems (BMS) for effective battery pack operation. A critical task for these systems is accurately estimating state … Read more
An initial high level look at the impact SOC estimation errors. State of Charge (SOC) State of Charge, abbreviated as SOC and defined as the amount of charge in the cell as a percentage compared to the nominal capacity of the cell in Ah. Errors in SOC accuracy can impact the operation of the battery … Read more
Use this EV Range Calculator to predict your electric vehicle’s driving range based on real-world conditions. Select your vehicle (Tesla Model 3 or VW ID.4) or input custom specs to get a tailored estimate. Custom EV Range Estimator Your Estimated EV Range 0 km Select Your Vehicle Choose a preset vehicle or use custom settings: … Read more
It is really important to understand the sources of error with the coulomb counting method as this forms the backbone for most SOC estimation algorithms. SoC Estimation by Coulomb Counting is based on the measurement of the current and integration of that current over time. There are five main sources of error with the coulomb … Read more
What is Remaining Useful Life (RUL)? Remaining Useful Life (RUL) is a key function declared by the battery management system. As per the title it gives you the remaining predicted lifetime of the battery based on its usage and degradation to the failure threshold [1]. It represents the period from the observation to the end of life … Read more
If you are in a battery design role there is always pressure on increasing usable SoC window. Nobody wants to pay for and carry around unused battery capacity. However, there are some really good reasons to restrict that window. High SoC and hence high cell voltage stresses the cell and significantly reduces the lifetime. Going … Read more
In the simplest terms the usable energy of a battery is the Total Energy multiplied by the Usable SoC Window. The total energy is the nominal voltage multiplied by the nominal rated capacity. However, if you have been through the Battery Basics you will have realised that the battery cell and pack do not have … Read more