Battery Management Systems (BMSs) are gaining a prominent role in the world of Electric Vehicle (EV) manufacturing. Looking to cut costs, adhere to government regulations, improve driver safety, and enhance the EV experience, Original Equipment Manufacturers (OEMs) and suppliers can monitor and manage the EV battery pack with an intelligent, cloud-based BMS. The benefits of this technology implementation should not be glossed over.
What Is a Battery Management System?
A Battery Management System (BMS) is a software solution that monitors and controls individual cells within a battery pack. The primary function of a BMS is to prevent damage and premature degradation to a battery, thereby extending longevity and improving the safety of battery operation. A BMS does this by estimating the State of Charge (SoC) of the battery cells and ensuring none of the cells are overcharged or overdischarged. The adoption of BMS software is an important milestone for EV manufacturing, as it makes driving experiences safer and more reliable. With fewer battery replacements, huge cost savings are awaiting OEMs and battery suppliers.
The following sections list six things OEMs and suppliers should know if they’re considering adopting a BMS for EVs.
1. You Should Probably Use Passive Cell Balancing for EV Battery Packs
Due to minor deviations in manufacturing and usage, not every EV battery charges/discharges at the same rate. A BMS software solution must be able to stop the battery pack from charging or discharging when any cell reaches the maximum or minimum voltage level. EV manufacturers can accomplish this through either passive or active cell balancing. While both generate similar results, the latter requires more sophisticated electronics and deeper pockets.
ABI Research believes passive cell balancing is the practical option for most EV applications because it is far more cost-effective and straightforward to implement. With passive cell balancing, the BMS identifies which cells have the highest SoC before rationing off the excess energy to other cells. This enables all EV battery cells to reach peak charge, although it’s at the expense of limited pack capacity to the weakest cells and energy wastage across the resistor.
Active cell balancing (for automotive), on the other hand, would be used to slightly improve charging times, heat generation, and usable capacity. This type of cell balancing will be limited to high-end cars looking to maximize performance. For example, the McLaren P1 and Mercedes-Benz VISION EQXX (a concept car, not in production) use active balancing.
2. OEMs and Suppliers Stand to Gain Enormous Cost Savings
Battery pack manufacturers—OEMs alone or through a battery supplier—can save significant development costs by adopting BMS software. BMS software solutions help increase the proportional available energy of an EV battery, thereby reducing its overall size while maintaining the same driving range.
It should be noted that when we refer to EV battery cost savings, we are speaking solely about the cost of cells, and not necessarily the battery pack. This is because a handful of battery components, such as power electronics, the cooling system, structural supports, and the BMS itself, do not scale in a corresponding manner.
ABI Research forecasts that the potential savings from adopting advanced BMS software will be more than US$12 billion annually by 2028.
3. There Are Four Ways to Determine the EV Battery State of Charge
A BMS is tasked with determining the EV battery's State of Charge (SoC), which indicates the remaining mileage range to the driver. The more accurate the indicator, the less range anxiety drivers will experience. This is important, considering that range anxiety is one of the top reasons why consumers hesitate to buy an EV.
Moreover, highly accurate SoC estimations increase the usable capacity of the EV battery because the required safety margins aimed at curbing the occurrence of overcharging/overdischarging are more lenient. There are four ways that the SoC estimation process can be carried out with the BMS, each with its own trade-offs.
- Voltage translation method
- Coulomb counting method
- Electrochemical Impedance Spectroscopy (EIS) method
- Kalman Filter (KF) method
To understand the trade-offs of each SoC determination method, download the Battery Management Systems for Electric Vehicles research report.
4. Second-Life Batteries Are a Must for EU Regulation Compliance
The European Parliament recently gave the green light for the Digital Battery Passport (DGP), which will digitally record the battery used in every EV sold in the European Union (EU). A BMS will facilitate the DGP as it can track critical data throughout the EV battery lifecycle. A major focus of the 2024-mandated DGP is to promote second-life applications for industrial batteries, forming a circular battery economy.
BMS software will provide key insights into an EV battery’s feasibility of being re-used or recycled by recoding and formatting data about:
- Remaining available capacity
- Current internal resistance
- The number of full charging and discharging cycles completed
5. BMSs Can Detect Vehicle Faults before Being Shipped Out
Cloud-based BMS solutions are important for automotive safety as the software can detect faulty battery cells, which can lead to fires. Consequently, brands can prevent disastrous public relations events, such as GM’s recall of 141,000 Chevrolet Bolts due to faulty batteries supplied by LG. EV battery faults can result in metal lithium plating, Solid Electrolyte Interphase (SEI) formation, dendrite formation, or electrolyte decomposition, and lead to thermal runaway and a spontaneous battery fire.
The BMS effectively diagnoses internal battery faults (overcharge, overdischarge, short circuits, cell degradation) by seeking out anomalies, such as changes in voltage, SoC, temperature, internal resistance, or swelling. Therefore, BMS software ensures that any EV with a faulty battery is weeded out during manufacturing.
6. More than 56 Million BEVs Will Ship with a Wireless BMS (wBMS) Solution by 2028
ABI Research assesses that EV OEMs will opt for wireless BMS (wBMS) over wired solutions. Wireless data transfers to a BMS appeal to OEMs as they reduce the weight of the battery and ease the complexity and overall costs of EV battery development/maintenance.
While GM is currently the only mass-market EV manufacturer implementing a wBMS, all OEMs will use wBMS software for their future vehicle models. We anticipate that all-electric automotive platforms will begin production in the mid-2020s. Considering these developments, 56.4 million Battery Electric Vehicles (BEVs) will ship with a wBMS between 2024 and 2028.
BMS Software Is the Future
Intelligent BMSs will become a staple in the automotive industry, especially as governments aim to ban ICE engines. However, for consumers and commercial fleet managers to trust the use of EVs, manufacturers and suppliers must deliver on increased safety and improved vehicle performance. BMS software is the best way to do that. When an EV battery uses an intelligent BMS solution, it means the battery will experience far slower degradation. By circumventing overcharging, overdischarging, and overheating of cells, the EV battery will last longer. As a result, the battery will have more charge cycles and miles driven.
SpectralX, the software-only solution from Qnovo, is a case in point; it extends an EV battery’s life to 1 million Kilometers (km), far outdoing current industry standards. Additionally, SpectralX allows EV drivers to charge their vehicles 10 minutes faster than normal, as well as increase driving range by 10%. Qnovo is a shining example of how far intelligent BMS software can go in addressing common pain points among would-be EV buyers, thereby encouraging more ubiquitous adoption of zero-emissions vehicles.
In its recent Battery Management Systems for Electric Vehicles report, ABI Research analyzes all the technological intricacies that OEMs and suppliers should grasp before adopting a BMS solution for EVs. Moreover, the report discusses the market expectations and main benefits of implementing this technology in greater detail. This content is part of our Electric Vehicles Rese
