Batteries have become such a part of our everyday lives that we do not notice them anymore, yet they serve essential functions. Think about the battery that is keeping your phone function or the battery in your laptop that allows you to work at remote locations. Electric bikes, hoverboards, digital cameras and even some types of vehicles rely on lithium batteries to power their electronics in the modern-day world. The problem is, lithium battery packs can be quite expensive, usually going for at least over $200 and they are obviously not tailor-made to fit your particular demands. Deciding to build your own DIY lithium battery pack is a great decision, and picking up this book tells me that you are interested in doing this. In this guide, I cover everything you need to know about building custom, tailor-made lithium battery packs. You decide what you want; then you build it. By choosing the particular specifications of a battery pack yourself, you can ensure that the pack can be customized toward the requirements of the project you are working on. I start my guide by telling you more about the process of building a lithium battery pack, including what you can do with such a pack and where they can be used. I also cover the basics of the different lithium battery types that you will find on the market today and point out which ones are preferred over the others, as well as why they are the preferred options. In addition to explaining all the terminology and other aspects there are to know about the process of building a DIY lithium battery pack, I also provide a complete step-by-step guide that tells you how you can plan the layout of your first lithium battery pack, how to find the right material and tools that will help you build a working, high-quality battery pack, and I also cover the process of installing a battery management system, an essential part of a battery pack that lets you effectively charge and discharge the device without causing an imbalance in the capacity or charge rate of any batteries included in the pack. Another relevant section covered in my guide is the safety guidelines that surround the building of your own DIY lithium battery pack. These safety guidelines should not be taken lightly, as potential hazards have occurred in the past with people who worked with lithium errors. Even though most hazards are not considered potentially harmful and usually only includes poor performance of the battery cell that has been affected, imbalances in the charge and discharge of these battery cells could potentially lead to more serious complications, such as the batteries exploding or catching on fire.