Latest Posts

All of the latest posts listed in date order.

  • Parallel then Series or Series then Parallel
    How should you connect battery cells together: Parallel then Series or Series then Parallel? What are the benefits and what are the issues with each approach? Series and Parallel The operating voltage of the pack is fundamentally determined by the cell chemistry and … Read more
  • 2019 Kia Niro
    The 2019 Kia Niro 64.8 kWh EV battery pack. Across the parts you will see Kia and Hyundai logos. The design and parts are all shared. The only difference is that the 2019 Hyundai Kona uses LG cells and the 2019 Kia Niro … Read more
  • BYD FC4680P
    The BYD FC4680P cell is a Lithium Iron Phosphate chemistry in the Tesla 4680 cell format. 4680 => 46mm in diameter and 80mm high A small plug in the top is described as an “explosion proof valve”. Only high level data is available … Read more
  • 2019 Hyundai Kona
    The 2019 Hyundai Kona is an electric vehicle produced from 2018 to 2021. This is the long range 64kWh usable pack. The 64kWh pack has five modules that are located under the floor in the main cabin with two stacked modules under the … Read more
  • Maximising Pack Energy Density
    How can we go about maximising pack energy density? What can we look at to reduce the mass and volume? Where are the opportunities given a defined cell? A great example of shrinking the size of a battery pack is the Mercedes Vision … Read more
  • Battery Assembly Times
    A look at battery assembly times based on available reports and data. Cell to Module The Peugeot e208 pack is rather complex looking, but the module is a quite standard 12 prismatic cells in an aluminium box. Module to Pack The Peugeot e208 … Read more
  • 2019 Ford Mach-E Std Range Battery
    A look at the 2019 Ford Mach-E std range battery pack. It is worth also looking at the body structure and the overall battery pack integration. Ford Mach E The Ford Mach E is built on the Global Electrified 1 platform that in … Read more
  • Battery Pack Density Fundamental Limit
    There is a battery pack density fundamental limit and that is the cell density. Obviously, but how close can we get to that limit? The following plot shows the pack gravimetric energy density plotted versus the cell gravimetric density. Added to this dataset … Read more
  • VDA Prismatic Cells
    VDA prismatic cells are based on a standard written by the German automotive industry. VDA stands for Verband der Automobilindustrie (German Association of the Automotive Industry). Prismatic Cells As the name suggests these are a prismatic block, normally with the outer case made … Read more
  • Gotion L600 Astroinno
    The Gotion L600 Astroinno is an Lithium Manganese Iron Phosphate (LMFP) based cell chemistry. Key Features This post has been built based on the support and sponsorship from: About:Energy, AVANT Future Mobility, Quarto Technical Services, TAE Power Solutions and The Limiting Factor.  Safety Data Gotion state zero thermal propagation … Read more
  • Key Parameters for Dielectric Fluids
    What are the key parameters for dielectric fluids as used in a battery pack? We take a look at a few reference papers to build an initial list. There are many options for cooling batteries. However, dielectric immersion cooling is seen as perhaps … Read more
  • Pareto Frontier of the Ragone Plot
    What battery packs are at the pareto frontier of the Ragone plot? With a database of over 300 packs we can plot power gravimetric density vs energy gravimetric density. Koenigsegg Regara The Koenigsegg Regera is a PHEV with a combined power of 1,119kW … Read more
  • Battery versus System Voltage
    When we look at the battery versus system voltage we have to remember that these are working together. In fact we have to look at the complete system and all components to ensure they can work together over the maximum and minimum voltage … Read more
  • Ford Mach E
    The Ford Mach E is built on the Global Electrified 1 platform that in itself is a heavily modified version of the C2 platform. The C2 underpins the Focus and Kuga. Based on the fact that the structure was originally designed for internal … Read more
  • Higher Voltage Packs
    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 … Read more
  • Fire Mitigation Strategies
    Author: Nrusimhan Seshadri, Balance Batteries Having looked at the challenges and regulatory standards relating to fire hazards posed by Li-ion batteries in the previous article, in this article we will have a look at some of the fire mitigation strategies deployed across 10 BEVs in … Read more
  • 2021 McMurtry Speirling
    The 2021 McMurtry Speirling is perhaps even more impressive an electric vehicle than the Rimac Nevera. Note: this is a very limited benchmark with just a few known parameters. This does though show the approach used to look at what the pack configuration … Read more
  • 2020 Rimac Nevera
    The form of this battery is complex, however, this is a hypercar that can afford an expensive battery pack design. Pack Mass: Rimac claim that the cell to pack mass ratio of the Nevera is 67% [1]. They also state that it uses … Read more
  • 2022 BTCC Hybrid Battery
    The 2022 BTCC hybrid battery as designed and manufactured by Delta-Cosworth. This is an extreme version of a Mild Hybrid Electric Vehicle (MHEV), thus has a small energy storage capacity that is designed to fill in the engine power. Specifications The nominal capacity … Read more
  • Hot Swap versus Fast Charge
    Swapping battery packs has come and gone, only to return in force with NIO having swapped 20 million packs (up to May 2023). However, how does this compare to fast charging? Battery Swap For this comparison we are using the 100kWh NIO ES6 … Read more
  • What Happens if a Cell goes into Thermal Runaway?
    Author: Nrusimhan Seshadri, Balance Batteries Thermal hazards of (Li-ion batteries) LiB’s are well known. The spontaneous exothermic release of energy from LiBs when subjected thermal, mechanical and/or electrical abuse is referred as thermal runaway. Though the chances of thermal runaway in modern EV’s … Read more
  • Stepped Fast Charge Limits
    We often see stepped fast charge limits as shown in this BMW iX3 graph. Often the result of a limited test regime applied by the cell supplier (in this case CATL) to establish the maximum charge current for the cell. These limits are … Read more
  • 2021 BMW iX3
    The 2021 BMW iX3 was the first electric vehicle off the BMW Gen5 battery system. We see 10 modules with double stacking under the 2nd row seats. The HV distribution and BMS are all located on top of the rear modules. Cooling pipes … Read more
  • BMW Gen5 Battery System
    The current batch of electric vehicles built on the BMW Gen5 Battery System. This design needs to survive until BMW swap to the Gen 6 design in 2025. The battery packs in the BEV and PHEV applications across SUV and Sedan platforms uses … Read more
  • Mastering 12V Lithium Iron Phosphate (LiFePO4) Batteries
    Unravelling Benefits, Limitations, and Optimal Operating Voltage for Enhanced Energy Storage, by Christopher Autey In the ever-evolving landscape of renewable energy and advanced energy storage solutions, Lithium Iron Phosphate (LiFePO4) batteries have gained widespread acclaim for their exceptional performance, reliability, and versatility. Among … Read more
  • What is Calorimetry?
    Author: Mario Toubes-Rodrigo, Application Specialist, H.E.L Group Calorimetry is a branch of thermodynamics that deals with heat transfer quantification. Heat can be transferred during a variety of processes, such as chemical reactions, phase changes, or dissolution of solutes in a solvent. Calorimetry follows … Read more
  • 150kWh NIO ES6
    The 150kWh NIO ES6 is ground breaking for a number of reasons and perhaps 260Wh/kg at pack level is not the most significant. This post has been built based on the support and sponsorship from: About:Energy, AVANT Future Mobility, Quarto Technical Services, TAE Power Solutions and The Limiting Factor.  … Read more
  • Mercedes Vision EQXX
    Cell to Pack design for the Mercedes Vision EQXX battery is just one of the aspects that make this an interesting vehicle. OK, this is a research vehicle designed to push the envelope. With expert engineering and Formula 1 thinking, our battery chemists … Read more
  • Continuous Current Rating
    At some point in the development of a battery pack design you need to consider the continuous current rating. Do this for charge and discharge as this then gives you one for the fundamental requirements to determine: Plotting continuous power versus system nominal … Read more
  • 2021 Lexus UX 300e Battery
    The 2021 Lexus UX 300e battery has a total energy of 54.35kWh and is formed from 288 Panasonic prismatic cells. A second tier of cells has been designed to fit under the 2nd row. This 2nd tier also appears to contain the BMS. … Read more