Battery Pack Development Stages
Over the years, we have helped customers at every stage of their custom battery pack may be. Customer do not always know the amount of resources and time it takes to bring their product-to-market.
The below outlines the four most common stages a customer is in when they approach us.
- Full Concept Battery Pack Development
- Battery Pack Specialty Process Design
- Established Specification Battery Pack Design
- Battery Packs Design/Build for Certification
Full Concept Battery Pack Development
The earliest stage of development comes when a customer knows what they want the battery for their product to do but aren’t quite sure how they want to build and develop it, further discussion is required.
Our engineering and technical team need to truly understand the customer’s requirements to create a scope of work that can be used as a starting point for the developments.
The biggest challenge with this type of development is that there tends to be many changes that are requested as the development process occurs which can extend the timeline, increase development costs, and create a higher higher-priced product. The first step is to work with the customer to help them finalize what their operating parameters and specifications are which in turn will help us develop a scope of work for the entire project.
The most important things for a customer to know at this point in their process, besides their technical requirements, include:
- What they have in a budget for the development cost.
- When they need to go to market.
- What their piece price needs to be in order toto make their product viable in the marketplace.
Too often on applications, the required functionality and the retail sale price of the product are not practical together. However, in most instances we can operate within our customer’s parameters by using either our domestic facility or low cost Asian manufacturing capabilities.
Examples of applications that we have developed in this manner are:
Medical Dispensing Squirt Bottle
We were approached by a company looking to develop a new product that required a small prismatic battery which needed to meet a specific dimensional footprint and would provide power to dispense a predetermined amount of fluid from an electronically assisted spray container. The battery needed to be designed to meet a target price for the customer to market their product, which required considerable engineering input to produce a battery solution for a lower-tech high-volume project. With all battery development projects, this would include samples, customer evaluation, product testing, formal approvals, and transportation certification on the battery to manage production volumes. In parallel to the battery development, Epec collaborated on the plastic enclosure design to house the battery which included a set of ultrasonic tooling to seal the battery to meet the required IP rating.
From concept discussion to approved design, the process took approximately 8 months. With the required tooling and regulatory certifications, we were able to begin shipping production in about 16 months. Also offering a stocking program to have product built, tested, and on the shelf to ship with short notice above and beyond the scheduled shipments.
A large OEM designing a new hand-held printing device requiring a custom battery and charger to support. The battery needed to provide enough power for the printer to cycle a predetermined amount, meet all certifications (which put the design emphasis on UL approval), and have BMS features to provide state of the art fuel gauging and place the battery in sleep mode for storage. Because the customer engineering group understood the requirements, the design process went smoothly with weekly updates that took approximately 18 months.
Once samples were developed, revised, and approved, pilot testing was required before the design could be locked in and the regulatory steps completed. Overall timeline on this project was about 30 months to complete all certifications and begin providing production releases.
Ventricular heart pump redesign of an existing marketed product, with the objective being to update electronics with improved state of the art features such as fuel gauging and charging features for the battery. Highest priorities were assigned to upgrading the battery to make it more efficient, completely reengineering the battery management system to improve functionality, redesign with class 3 medical requirements while both utilizing the same enclosure and keeping the same esthetics for customer use and familiarity. Our process included very close collaboration with the customer engineering group. Because the customer engineering team was very familiar with their design, the transition to the new design was straightforward.
With scheduled weekly updates, the design updates were completed in about 6 months. The customer also requested dual cell certification, which required considerable sample submissions and testing coordination. Time spent, starting with the first discussions to final approval on the design, took approximately 18 months, and with all the dual certifications, another 12 months to begin building and supporting production quantities.
Mobile Security X-ray Machine
Mobile security x-ray machine, designed with dual batteries to power the device, which are kept under 100watt hours each for regulatory ease. The electronics were designed to provide state of the art fuel gauging, dual safety protection, and batteries configured to fit a customer-designed enclosure which we collaborated on. The battery management system needed to simultaneously charge both batteries from the system level and provide a sleep mode for longer periods of storage. This battery was a straight-forward design; the sample process only required one re-iteration to change some of the charging and discharging parameters, so the design was completed in 8 months.
With regulatory transportation certification included, we were certified and began supporting production in 14 months. With this battery and many of the designs we support, we offer our customers inventory programs to support spikes in demands.
Battery Pack Specialty Process Design
When unique expertise or equipment is required to complete the specifications of a battery pack, customers need to work with companies that focus on battery projects as the investment in specific equipment and battery technologies are the key to getting these processes done cost effectively and in a timely manner.
Things such as ultrasonic welding equipment, vacuum, and dispensing equipment for potting or encapsulation materials, or CNC machines for the development and completion of production tooling are just a few of the specific items needed to fulfill these requirements.
These solutions can be as complicated as sixty-four cells spot welded together with three circuits in one battery pack or a simple as a single cell solution.
Typically, the customer has a need for an additional process to be performed on their battery pack but may not have the resources to design or manufacture in-house.
Here are a few examples and how they might impact timelines:
1. Potting the battery pack to make it waterproof using many different types of materials.
The biggest factors here are understanding the IP ratings, the flammability specifications and the amount of temperature, vibration and/or pressure that the battery packs will see during their operation.
Once we have a clear specification, we can then choose the correct materials, create tooling, and being to create samples quickly to test out the design parameters. As is true with all development, much of the timeline is dependent upon how available the materials are that meet the requirement and a big part of our job is to make sure that the customer knows what is most commonly available to minimize any delays in prototyping or further down the road in production.
2. Having an enclosure designed and ultrasonic tooling developed to have a battery pack fit into.
Plastic Enclosures: Depending upon the IP rating and the chosen method of attaching the cover, this can take anywhere from 3 weeks to 10 weeks to get completed.
We start by understanding the environmental factors associated with the product once in the field and then we create 3D drawings to begin the process which moves then the 3D printed samples to do some preliminary testing to make sure that we can meet the customer specification.
From there we go back and forth until we get a final design and then we move into creating the hard tooling and the pre-production samples for approval.
Metal Enclosures: This goes through much of the same processes as we list above, but rather than 3D printing the samples we work with prototype “metal bending” houses to quickly get samples to test. Once that is completed we can get production started relatively quickly depending upon the complexity of the part.
3. Taking an existing battery pack and adding a heating solution to it to improve performance in colder environments.
Many battery packs are required to work in extreme environments and while batteries prefer the cold over the heat, going below certain temperatures has a dramatic effect on the battery performance. Because we have over 10 years of experience design and manufacturing thin silicone rubber heaters and ultra-thin Kapton heaters, we can design the precise solution necessary for every application.
4. Specialty connectors or wire harnesses added to a pack.
Specialty Connectors: In many instances, customers will require a customized connector solution for a battery pack. This could be a customized connector with a locking mechanism which is also IP67 compliant, or a hard gold plated PCN used as a contact point to the device with ultra-long life-cycles due to the thickness.
Wire Harnesses: When a battery pack is installed inside of a device, frequently there are complex cables that are used for charging, discharging, monitoring, and safety. By having us design and install the assemblies to the battery pack we can assure that everything is operating correctly before our customers begin using the finished product.
5. Specialty testing requirements with serialized documentation required.
Medical, military, and aerospace applications are just a few of the areas in which we have expertise in meeting testing and documentation requirements. For medical devices, this usually includes actively serializing every component and battery pack to quickly and accurately identify any specific units that may experience a problem. This is also important for military and aerospace programs, as well as performing and passing HALT and HASS testing in house. Designing and manufacturing custom battery packs to withstand shock and vibe testing requires significant experience.
In most cases the battery is already designed and it’s the specialty processes that need to be developed. Our engineering team can quickly provide engineering feedback and pricing on the tooling, development, and production pricing after we have been provided with drawings and technical specifications.
Established Specification Battery Pack Design
For a design that uses custom housings (soft pack, low pressure molding, plastic housings), a very detailed specification outline with answers from our two questionnaire documents makes the quotation for the development process and manufacturing price very accurate.
To reach this stage means the customer has spent a significant amount of time on the specifics of their application. Having established design details will dramatically reduce the development timeline, setting a very clear direction to production.
The process then moves to us developing all drawings, schematics, software, firmware, BMS, and all additional components of the battery pack. The reason we ask for our questionnaires to be filled out prior to starting the process is to minimize any additional work required in the future if one of the requirements that isn’t listed at the beginning requires changes in other parts of the design.
This development considers many of the following:
- Hardware Development: Manufacturer independent selection of the optimum cell chemistry to fulfill all customer requirements, battery management system (i.e. PCB, protective circuits, communication) to fit sophisticated applications, including charging technology, fuel gauging interface.
- Software Development: Host and user interface parameters (SMBUS, PMBUS, 1-Wire, I²C, etc.), specific configuration algorithms for safety mechanisms and charging parameters.
- Mechanical Development: Custom housings (softpack, low pressure molding, plastic housings), Custom connectors if required.
- Environmental Requirements: State-of-the-art laboratories for all relevant environmental tests, such as climate, EMC, shock and vibration, etc.
- Certification Management: UL, CE, IEC, ITL, UN 38.3.
- Quality Management: Managing our production through our ISO9001:2015 standard and with our proven NPI process to make sure that we seamlessly get from prototype to production.
- Testing and Programming: Part of our process is to design and develop all fixtures and programs needed to fully program and test each battery pack in house.
The objective for any design is to keep the costs down and the timeline tight and our experience has demonstrated that the only way to do that is to get an agreed upon specification developed prior to starting development. Our engineering team is here to work with you to help finalize and review the specification to make sure that we can meet all your requirements.
Battery Pack Design/Build for Certification
At this stage the customer has a very specific idea of what they want electrically and mechanically. They may even have a rough drawing of what they need and/or previous experience designing batteries.
This allows us to move quickly through the entire process and into production as much of the upfront work has been completed. It will also dramatically reduce the development costs and provide customers with different production pricing options.
Here are a few common examples of customer service expectations at this stage of development:
- Those looking to have the protection circuity or other standard Battery Management System (BMS) components added to the design.
- Need the design completed and certified for IEC, UL, or UN 38.3. We can manage the entire processing of all certification submittals as we have long standing professional relationships with agencies that allows us to quickly navigate to an approval. This includes understanding how many and what type of samples need to be submitted for the specific battery type.
- Customers looking to upgrade an existing product that has been in service for many years.
- Companies who don’t have the resources to ship lithium batteries as it requires all individuals responsible to be certified by a recognized organization. Our service ensures that all your certifications are actively managed. This includes managing yearly renewals, ensuring your product can meet the new and yearly requirements, and minimizing your liability by making sure that your labeling, packaging, and shipping methods are always in compliance with DOT regulations. Even NiMH must be registered if they are manufactured in Asia and shipped via air freight to the USA.
In all instances the customer has completed a significant amount of the upfront work required so we are able to quickly create scope of work to finish the project and move into development and production.
Most of these cases involve the customer having already documented the following:
- Fully-completed questionnaire. All boxes are filled out which indicates that you fully understand what you need the pack to do and it will quickly allow us to check your requests against the parameters.
- Have determined which cell chemistry that they would like to use. We can determine which brand is used based upon pricing budget and operating parameters.
- At a minimum - 2D drawings of an enclosure exterior (if applicable). 3D drawings would be even better. This must include specifications on color, finish, and material.
- Understanding and documenting of how they plan on connecting to the pack and how they want to charge the pack if rechargeable.