Skip main navigation

Battery Safety & Types of Battery Abuse

Battery Safety & Types of Battery Abuse used in E-Buses.
The back part of an E-Bus being opened to show the battery inside.

Making sure batteries are safe and work really well is very important for E-Buses. E-Buses rely heavily on efficient and secure battery systems, making it crucial to comprehend potential abuse scenarios and the stringent safety measures in place to mitigate risks.

This article will focus on the following topics:

  • the importance of adequate training in battery handling
  • types of battery abuse that can lead to safety issues
  • causes of battery failure
  • strategies to minimize battery abuse
  • the significance of a Battery Management System (BMS).

Battery Safety & Types of Battery Abuse

Battery safety problems arise when batteries are mishandled. These problems occur when batteries are used outside their operating space as designed, because of poor design, or because their service life has been exceeded.

Heat and gas generation are the most common responses of batteries to abused conditions; the most severe consequences occur when stored energy is released rapidly and unintentionally, that is why when handling batteries, or when performing any type of testing, it is necessary to have adequate training.

Two photos of batteries that went to a thermal runway, being burnt and not able to be used anymore. Battery after undergoing thermal runway. Royal Society of Chemistry (2018)

Types of battery abuse that can lead to safety issues

Battery failure can be caused by:

Diagram showcasing the different causes of battery failure, including mechanical, electrical and thermal abuse.Click to expand. Causes of battery abuse. PEM Motion (2023)

Electrochemical abuse is a type of battery misuse that can cause serious problems. When the electrochemical material inside a battery is pushed beyond its intended limit during usage, it leads to battery failure. This overuse or exceeding of safe operating limits can damage the battery and affect its performance. Understanding and preventing electrochemical abuse is crucial for ensuring the longevity and efficiency of batteries, especially in the context of electric buses.

If you want to find out more about battery abuse, click in the following Link.

Battery Failure – Mechanical Abuse

Mechanical abuse commonly occurs when an externally applied force deforms the battery, and this can be caused by automobile collisions. Automobile collisions are one of the causes of mechanical abuse, and punctures to the underside of the chassis by foreign bodies also cause deformation.

Driving on an uneven road surface has a high potential to cause intrusions into the bottom of the battery from the bottom of the chassis. Mechanical abuse can cause an internal short circuit because mechanical abuse usually breaks the battery separator.

Diagram of two batteries showcasing the types of mechanical abuse: penetration and crush.Click to expand. Example of mechanical abuse in a battery. PEM Motion (2023)

Battery Failure – Electrical Abuse

Electrical abuse refers to the abnormal operation of electrical components, such as short circuits, overloads, and over-discharges. It is usually related to failures of the battery management system.

For example, some accidents may be due to fast charging. An improper fast charging process can cause lithium deposition on the carbon anode because the intercalation rate of the lithium atoms is slower than the migration rate. It is recommended to reduce the current rate during charging if you are still determining whether a vehicle is at risk of danger caused by fast charging.

Diagram showcasing two types of electrical abuse that cause battery failure, including internal short circuit and overcharge and overdischarge.Click to expand. Example of electrical abuse in a battery. PEM Motion (2023)

Battery Failure – Thermal Abuse

Thermal Abuse can result from internal or external heat sources, which drive the cell components into thermal runaway, and heat can trigger a self-reinforcing chain reaction in the battery, escalating its temperature.

In extreme cases, thermal runaway can cause batteries to catch on fire or explode, and in minor issues, the battery will melt.

Thermal runaway can be caused by:

  • internal short circuit 
  • overcharging a battery beyond its safe max voltage
  • external temperatures, both high and low, can impact battery performance and possibly trigger the chain reaction leading to thermal runaway.

In short thermal runaway is caused when the heat within the battery exceed the amount of heat it can release.

A diagram of a battery showcasing the thermal abuse in a battery caused by overheating.Click to expand. Example of thermal abuse in a battery. PEM Motion (2023)

Uncovering the root causes of these battery failures often leads us to a common denominator—abuse conditions. Mechanical, electrical, thermal and electrochemical abuse are among the conditions that batteries can endure, triggering and causing the different types of battery failure, as shown in the next diagram.

Diagram showcasing the relation between the three different types of battery failure and how if they combine can damage the battery and lead to a several battery failure.Click to expand. Abuse conditions that lead to batttery failure. PEM Motion (2023)

Course mascot saying "Batteries can fall in various ways, resulting in fire, explosion, and the release of toxic gases, as shown in the diagram!" Course Mascot. PEM Motion (2023)

Importance of a Battery Management System (BMS)

A Battery Management System (BMS) is an essential part of batteries in E-Buses and other electric vehicles, as it helps preserve the batteries, and is there to protect the lithium cells from excessive temperatures.

The system helps control the battery temperature by opening and closing valves to ensure the temperature is appropriate, and in worse cases, it will shut down the battery to prevent it from damaging. Every battery should have a BMS, as it is a crucial safety standard and helps protect the longevity of the battery.

General features of a BMS:

  • manages cell charging balance
  • manages cell voltage
  • manages charge control
  • internal short circuit detector
  • manage cell temperature
  • manage cell current.

Image of a Battery Management System with its internal components. Overview of a Battery Management System (BMS). Balasingam et al. (2020)

Conclusion:

It is essential to know the benefits of using batteries or energy storage systems, but it is also crucial to know the accidents caused by battery failures. In this module, we learned about the different types of failures and how they can occur.

That is why it is necessary to have proper training and enough information to know how to work with these electrical systems safely and to be able to handle them appropriately, and finally we also learned ways to minimize battery abuse and how the BMS helps to protect batteries.

This article is from the free online

Exploring the World of Electric Buses: Advancing Zero-Emission Public Transport

Created by
FutureLearn - Learning For Life

Reach your personal and professional goals

Unlock access to hundreds of expert online courses and degrees from top universities and educators to gain accredited qualifications and professional CV-building certificates.

Join over 18 million learners to launch, switch or build upon your career, all at your own pace, across a wide range of topic areas.

Start Learning now