from chemistry to pack
For most simple peak power calculations we will be interested in the Direct Current Internal Resistance (DCIR) value for a new cell at 50% SOC (25°C, 10s), Open Circuit Voltage (OCV) and minimum voltage. Note: this is just an estimation and this needs to be compared to the manufacturers specifications and tested values. However, as … Read more
Knowing the power demand for a battery cell or pack is really useful, but how do you turn that into a current demand? The following image shows the solution we use in the Battery Calculations Workbook and in the Vehicle Model. At first it can look daunting, but it is quite simple, maybe too simple … 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
Why are we moving to higher voltage packs? We know that the battery cell is not a perfect current source as it also has an internal resistance. Symbolically we can show a cell with the internal resistance as a resistor in series. Rint is the DC internal resistance, sometimes abbreviated as DCIR. The DCIR is not … Read more
There can be a number of reasons to do an Emergency Shutdown of a battery pack and a number of approaches to this. Hence interesting to layout and discuss this topic. It should be noted that we are discussing the BMS opening the contactors. The main reasons for an emergency shutdown are: Each of these … Read more
There are a number of reasons to estimate the charge and discharge current limits of a battery pack in real time: Hence this is a key function of the Battery Management System (BMS). The difficulty is that the current limits are dependent on a number of factors, for the cell alone we should consider the … Read more
In this Article you will the details about the Rivian R1T Battery pack and Module Construction, Standard Specification, Key Pack Metrics.
In this Article, we will compare different Cylindrical Cell Sizes used in electric Vehicles. 4680 vs 21700 vs 18650.
Equations and Calculator for DC to DC Converter: Buck, Boost and Bidirectional Buck and Boost Converter. Have Fun
In this article, we will look at the Battery Module Production. There are 7 Steps for Battery Module Production.