Battery Pack Development Stages

Epec supports custom battery pack programs at every stage, from early concept through certified production. Development timelines, costs, and risks vary widely depending on how defined the electrical, mechanical, and regulatory requirements are. A clear specification early in the process is the primary lever for reducing redesign, delays, and cost growth.

At a Glance: Battery Development Stages

• Supports all development stages: Epec works with customers from early battery pack concepts through established specifications and certified production, adapting engineering effort to how defined the requirements are.
• Specification clarity drives cost and timeline: Clearly defined electrical, mechanical, environmental, and regulatory requirements early in the process significantly reduce redesign, delays, and overall development cost.
• Integrated engineering and compliance expertise: Battery management systems (BMS), enclosures, potting or encapsulation, heating solutions, testing, and certification are developed together to ensure performance, safety, and production readiness.

---

Battery Pack Development Stages

Epec works with customers across four common stages of custom battery pack development. Each stage reflects how defined the application requirements are and how close the design is to production readiness. Understanding your current stage helps set realistic expectations for timeline, investment, and engineering scope.

• Full concept battery pack development
• Battery pack specialty process design
• Established specification battery pack design
• Battery pack design and build for certification

---

Full Concept Battery Pack Development

This earliest stage begins when a customer understands what the battery must do but has not yet defined how it will be built. Electrical, mechanical, environmental, and cost requirements often evolve during development, which can extend timelines and increase total cost if not managed carefully.

Epec’s engineering team works closely with customers to turn initial goals into a defined scope of work. Finalizing operating parameters early, such as power needs, form factor constraints, and target pricing, creates a foundation that reduces downstream changes and redesign.

Key Considerations at This Stage

• Development budget expectations
• Target market launch timing
• Required piece price for product viability

When functionality and retail price appear misaligned, Epec can often adapt designs using domestic manufacturing or lower-cost Asian production options without compromising requirements.

---

Concept-Stage Application Examples

Medical Dispensing Squirt Bottle

A compact prismatic battery was designed to meet strict dimensional limits while powering a defined dispensing cycle count. Parallel development of the plastic enclosure and ultrasonic tooling enabled the required IP rating. From concept to approved design took approximately 8 months, with production shipping beginning around 16 months after project started.

Portable Printer

A custom battery and charger were developed to support a defined print cycle requirement while meeting certification requirements, including UL. Integrated battery management system (BMS) features supported fuel gauging and sleep mode for storage. Design was completed in about 18 months, with full certification and production readiness achieved around 30 months.

Heart Pump

An existing product was redesigned to update electronics, improve efficiency, and implement a reengineered battery management system while retaining the same enclosure and external aesthetics. Class 3 medical requirements and dual cell certification significantly shaped the process. Initial design updates were completed in roughly 6 months, with total time to production support extending beyond 30 months due to certification requirements.

Mobile Security X-ray Machine

Dual batteries were designed under a 100 watt-hour limit per pack to simplify regulatory approval. The BMS supported simultaneous charging, fuel gauging, safety protection, and sleep mode. Design completion took approximately 8 months, with transportation certification and production support achieved in about 14 months.

---

Battery Pack Specialty Process Design

Some projects require unique processing beyond standard battery assembly. These specialty processes typically occur when the electrical design already exists, but environmental, mechanical, or regulatory requirements introduce additional complexity.

Common Specialty Processes Include:

• Potting or encapsulation to achieve waterproofing or environmental protection
• Custom enclosure design with ultrasonic welded tooling
• Integrated heating solutions to improve low-temperature performance
• Specialty connectors or integrated wire harnesses
• Customized testing with serialized documentation

These solutions can range from a single-cell assembly to complex packs with dozens of cells and multiple circuits.

Potting and Encapsulation

Material selection depends on IP rating requirements, flammability specifications, and exposure to temperature, vibration, or pressure. Once requirements are defined, Epec selects materials, develops tooling, and builds samples for validation. Material availability often influences prototyping and production timelines.

Plastic Enclosures

Plastic enclosures typically require 3 to 10 weeks, depending on IP rating and sealing methods. The process includes 3D modeling, printed prototype samples, iterative testing, and final hard tooling prior to production approval.

Metal Enclosures

Metal housings follow a similar process but rely on prototype metal-bending services rather than 3D printing. Production can begin quickly once form and function are validated, depending on overall part complexity.

---

Heating Solutions for Cold Environments

Battery performance drops significantly at low temperatures. With over a decade of experience designing thin silicone rubber and ultra-thin polyimide heaters, Epec integrates heating solutions tailored to each battery pack and application environment to maintain performance consistency.

Specialty Connectors and Wire Harnesses

Many battery packs require customized connector solutions, including locking mechanisms or IP-rated designs. Integrated wire harnesses manage charging, discharging, monitoring, and safety connections. By designing and installing these assemblies directly into the battery pack, Epec ensures system-level functionality before deployment.

Testing, Documentation, and Regulated Applications

Medical devices, military programs, and aerospace systems frequently require advanced testing and documentation. For medical devices, this often includes serialization of every component and battery pack to enable traceability. Epec also supports rigorous shock, vibration, HALT, and HASS testing when required.

These programs demand specialized equipment, documentation discipline, and experience to manage certification complexity effectively.

---

Established Specification Battery Pack Design

At this stage, customers have already invested significant time in defining their application. Clear specifications reduce development risk, shorten timelines, and provide a direct path to production.

Epec uses completed questionnaires, drawings, and defined electrical requirements to develop all necessary schematics, firmware, software, BMS functionality, and mechanical components. Early alignment prevents late-stage changes that affect other parts of the design.

Development areas commonly addressed:

• Hardware design, including cell chemistry selection and battery management system architecture
• Software and communication interfaces such as SMBUS, PMBUS, I²C, or 1-Wire
• Mechanical housings, connectors, and enclosure solutions
• Environmental testing and laboratory validation
• Certification management across UL, CE, IEC, ITL, and UN 38.3
• In-house testing, programming, and production fixture development

---

Battery Pack Design and Build for Certification

Customers at this stage often require protection circuitry, formal certification, or upgrades to legacy products. Epec manages certification submittals, sample coordination, and ongoing compliance requirements, including labeling, packaging, and shipping regulations.

This approach is especially valuable for companies that do not maintain in-house lithium shipping certifications or ongoing compliance resources.

---

Typical Timeline and Power Reference

Category	Class I - Basic Pack	Class II - Intelligent Integrated Pack	Class III - Advanced High-Reliability Pack
Primary Application	Simple portable devices, handheld products, entry-level systems	Industrial, medical, communications, and integrated OEM systems	Defense, aerospace, robotics, AGV, high-power industrial, mission-critical systems
Cell Count	1-10 Cells	2-20 Cells	10+ Cells
Battery Chemistry Support	Li-Ion, LiFePO4, NiMH	Li-Ion, LiFePO4, NiMH, custom chemistries	Advanced lithium chemistries and custom energy systems
Battery Management System (BMS)	Basic protection and balancing	Advanced BMS with communication	Multi-layer intelligent BMS with redundant safety controls
Cell Balancing	Passive balancing	Passive or active balancing	Advanced active balancing with diagnostics
Protection Circuits	Overcharge, over-discharge, short circuit	Overcharge, over-discharge, overcurrent, thermal protection	Multiple redundant protection circuits including thermal runaway mitigation
Communications	None	CANBus, SMBus, I2C, UART, RS485	Advanced communications with telemetry and remote diagnostics
Smart Features	Basic LED indication	Fuel gauging, diagnostics, communication feedback	Predictive analytics, cloud integration, advanced diagnostics
Enclosures	Simple shrink wrap or basic enclosure	Custom enclosure options	Fully engineered ruggedized enclosure systems
Environmental Protection	Standard commercial environments	Industrial-rated environmental protection	IP-rated, sealed, ruggedized, vibration/shock resistant
Thermal Management	Minimal	Integrated thermal monitoring	Advanced thermal control and heat dissipation systems
Testing	Basic electrical testing and validation	Functional, environmental, and communication testing	Comprehensive validation including environmental, lifecycle, vibration, thermal, and safety testing
Certifications	UN38.3 support	UN38.3, IEC, UL support	UL, IEC, UN38.3, MIL-spec and customer-specific compliance
Manufacturing Complexity	Low	Medium	High
Typical Lead Time	6 weeks for prototypes, 10 weeks production lead time*	8 weeks for prototypes, 10 weeks production lead time*	12-16 weeks for prototypes, 20 weeks production lead time*
Engineering Involvement	Basic application review and standard pack configuration customization required	Collaborative engineering support including communication integration, enclosure design, and system optimization	Full custom engineering engagement including electrical, mechanical, thermal, software, compliance, and system-level integration
Typical Industries	Consumer, commercial electronics, rtacking devices	Medical, industrial controls, communications	Defense, aerospace, robotics, autonomous systems, transportation
NOTE ON LEAD TIMES AND CERTIFICATIONS:
Custom battery pack projects that require regulatory certifications must complete the applicable testing and approval process before final production can begin. Typical certification timelines include UN38.3 transportation testing (approximately 6 weeks), UL certification (approximately 12 weeks), and IEC certification testing (approximately 14 weeks), depending on the complexity of the design and testing requirements.
As a result, total project timelines for fully certified battery systems can range from approximately 12–26 weeks or longer from initial design release through certification completion. Production lead times for volume manufacturing begin only after all customer, testing, and final design approvals have been completed, as the battery pack design is generally frozen and finalized during the certification process

---

Frequently Asked Questions

Quick Links

• What are the considerations for encapsulation and potting?
• What are the considerations for enclosure design?
• What should I know about battery management systems (BMS)?
• What matters for medical device applications?

What are the considerations for encapsulation and potting?

Encapsulation and potting depend on IP rating, flammability requirements, and environmental exposure. Material availability can significantly influence development and production timelines.

What are the considerations for enclosure design?

Enclosure design must account for sealing method, IP rating, and environmental conditions. Plastic and metal enclosures follow different prototyping and tooling paths.

What should I know about battery management systems (BMS)?

The BMS controls safety, charging, fuel gauging, and storage modes. Its design is closely tied to certification requirements and application behavior.

What matters for medical device applications?

Medical applications require serialized components, strict documentation, and often extended certification timelines to meet regulatory and traceability requirements.

---

Here To Help at Every Stage

From early concept through compliance and production support, Epec’s engineering team works with you to define requirements clearly and move your battery pack program forward with confidence.

Request a Quote Request Design Support Request More Information