Epec's Blog | Electronics Manufacturing Solutions

Designing a custom battery pack for your application requires figuring out the power specifications. Yet there are several other considerations that dictate the type of battery chemistry to use. In addition to the current, capacity (amp-hours), size requirements, cell configuration, and the number of cells for the battery pack within the application, the voltage must also be determined.

Manufacturing custom battery packs requires comprehensive input from the customer. A customer offers details regarding the application, the power requirements of the battery, and the type of shelf life for the battery pack. The customer also expects battery testing to occur at the end of production to ensure quality and that the battery will work for the application.

Custom battery pack development costs are driven by a combination of technical and regulatory decisions, including battery chemistry, cell count, enclosure design, smart battery functionality, and certification requirements. Understanding these factors early helps balance performance, longevity, and budget while avoiding unnecessary development expenses.

Lithium-ion and lithium iron phosphate (LiFePO4) are the two most widely used lithium-based chemistries in custom battery packs for portable devices and high-power applications. Lithium-ion delivers higher energy density for compact, high-speed electronics, while LiFePO4 emphasizes safety, thermal stability, and extended cycle life. Selecting the correct chemistry directly impacts performance, lifecycle, safety requirements, and regulatory compliance.

It is common to explore different power supply options when designing your applications. However, one that often gets neglected is the differences between the types of battery cells in your portable applications. There are a lot of similarities between battery cells, but also very many differences that make certain cells more efficient than others when it comes to application.

The last 18 months have been some of the most challenging that many of us have had to deal with both personally and professionally. It has often felt like we were riding waves, coming closer to things getting a little more normal, only to have them change radically. Looking forward to the next 18 months, I don’t see those changes getting any easier for us or our industry.

Battery power requirements involve many factors. Beyond having enough power to run the application, customers also take into consideration battery capacity, charging/discharging rates, and environmental conditions that could impact the battery's functions. Before the battery packs development starts, there are other aspects about the power requirements that need to be evaluated. These aspects may impact the size of the battery, if there are any logistical restrictions that come into play and what types of certifications are required.

Applications with high-power needs and complex systems may use lithium batteries to operate. Lithium batteries can pack a high-energy density into smaller pack sizes, making them lightweight and small enough to be used in common everyday products such as cell phones, laptops, tablets, and hoverboards. However, the battery's chemistry can create safety hazards when not being constantly monitored.

Customers requiring batteries for their products or applications have become savvier when it comes to the developmental phase of the battery packs. They understand that by having researched power requirements, dimensions of the pack compartment, battery chemistries, and cabling specifications, the customer can develop more comprehensive design documents. Then, the battery pack manufacturer can use these specifications to get started on the development and tooling stage immediately.

When designing a custom battery pack, a topic that will come up between the manufacturer and the customer deals with the fuel gauge. The battery fuel gauge can be found in a range of everyday devices that we use, such as cell phones and computers. The function of the fuel gauge is to inform the customer on how much state of charge (SoC) and state of health (SoH) is left in the battery. The fuel gauge can predict the remaining capacity by measuring the voltage, battery temperature, and current.