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9 Questions to Ask Your Li-Po Battery Supplier for OEM Projects

As a dedicated manufacturing partner for Original Equipment Manufacturers (OEMs), our team at Hanery engages in hundreds of technical consultations every year. We’ve learned that the success of a high-volume product launch often hinges on one of the earliest decisions made: the selection of the battery supplier. For an OEM, this choice is profoundly strategic. Your brand’s reputation, carefully built over years, is on the line with every single unit that ships. The battery is not just a component; it is the heartbeat of your product, and its failure can lead to catastrophic brand damage.

We’ve seen the consequences when this decision is rushed. An established brand of smart home devices came to us after their first 50,000-unit production run was plagued by inconsistent battery performance, leading to a spike in warranty claims. Their previous supplier, who had provided perfect prototypes, could not maintain quality at scale. This is a classic, and costly, scenario. OEM projects operate at a scale where small inconsistencies become massive financial and logistical problems. You need more than a supplier; you need a manufacturing partner with the systems, processes, and mindset to operate as a seamless extension of your own operations.

This is why we have compiled this list of nine critical questions. These are the questions that we, as manufacturers, believe every serious OEM buyer should ask. They are designed to cut through the sales pitches and get to the core of a supplier’s operational capability. Answering them will help you differentiate a true OEM-grade partner from a standard component seller and build a foundation for a successful, long-term manufacturing relationship.

1. How Do You Ensure Batch-to-Batch Consistency for High-Volume Production?

For an OEM, consistency is everything. The thousandth battery pack must be identical in performance, safety, and build quality to the first. We’ve seen many suppliers who can produce a handful of perfect prototypes but falter when faced with the challenge of replicating that quality across tens of thousands of units. This issue, often called “quality fade,” is a major risk for any established brand.

Moving Beyond the "Golden Sample" with Statistical Process Control (SPC)

The “Golden Sample”—the perfect, approved prototype—is the starting point, not the end goal. A truly professional OEM partner uses the Golden Sample to define the critical parameters for mass production and then uses Statistical Process Control (SPC) to ensure those parameters are met, every single time. SPC involves continuously monitoring key process variables—such as weld strength, electrolyte volume, and internal resistance—and plotting them on control charts.

Example of a Process Control Chart (SPC)

This data-driven approach allows us to detect and correct any minor deviations before they can escalate into a quality problem. When we partner with an OEM, we can share this SPC data, providing transparent, verifiable proof of our process stability.

The Role of Automation in Reducing Human Error

Consistency is difficult to achieve with manual processes. At Hanery, we have invested heavily in automation for critical production stages. This includes automated cell grading and sorting, laser welding for interconnects, and computerized functional testing of every BMS. Machines do not get tired or have a bad day. They perform the same task with the same precision thousands of times. This investment in automation is a direct investment in the consistency that our OEM clients’ brands depend on. Ask any potential supplier to detail the level of automation on their production lines.

2. What Is Your Real Production Capacity, and How Do You Manage Scalability?

Your sales forecast is not a flat line. You have seasonal peaks, new product introductions, and promotional periods that can cause demand to fluctuate dramatically. An OEM partner must have not only the baseline capacity to handle your average volume but also the flexibility to scale up to meet your peak demand without compromising quality or lead times.

Translating "Factory Size" into Tangible Output

Many suppliers will talk about the square footage of their factory. This is a vanity metric. What truly matters is their tangible output and how they manage their production schedule. We are transparent with our OEM partners about our real-world capacity, measured in Watt-hours (Wh) per month, and the current utilization of our production lines.

We practice a formal Sales and Operations Planning (S&OP) process. When an OEM partner provides us with their rolling 6-month forecast, we integrate it directly into our master production schedule. This allows us to:

Allocate Line Capacity: We reserve dedicated time on our production lines for your products in advance.
Procure Long-Lead-Time Components: We can place orders for critical components like specialized BMS ICs or custom cells, insulating your project from supply chain disruptions.
Plan Labor: We can schedule our workforce to ensure we have the skilled technicians ready to handle your production ramps.

Demonstrating a Proven Track Record of Scaling

Talk is cheap. Ask a potential supplier to provide a case study (anonymized, of course) of how they have managed a significant production ramp for another OEM client. They should be able to describe how they increased output, what challenges they faced, and how they overcame them. For example, we worked with a leading consumer electronics brand whose product demand tripled after a successful holiday season. Because we had a strong S&OP process in place based on their forecasts, we were able to leverage our pre-booked capacity and buffered raw material stock to meet their surge in demand without missing a single delivery. This is the kind of proven scalability that an OEM needs.

3. Can You Provide a Detailed Breakdown of Your Quality Management System?

Every supplier will claim to have an ISO 9001 certificate. While this is a necessary baseline, the certificate itself doesn’t tell you the whole story. For an OEM, whose QA team is responsible for the quality of the final product, you need to dig much deeper into the “how” and “why” of their Quality Management System (QMS).

Deconstructing the Quality Process: From IQC to OQC

A robust QMS is a multi-layered system that builds quality in at every stage. We encourage our OEM partners’ QA engineers to audit our process, which includes:

Incoming Quality Control (IQC): We don’t just trust our sub-suppliers. Every batch of critical raw materials—from the lithium cells to the BMS ICs—undergoes rigorous testing and verification before it is accepted into our inventory.
In-Process Quality Control (IPQC): We have dedicated QC checkpoints at critical stages on the production line. This includes automated optical inspection (AOI) of solder joints and Hi-pot testing to check for insulation integrity.
Final Quality Control (FQC) & Outgoing Quality Control (OQC): Every single finished battery pack undergoes a comprehensive end-of-line functional test. This is not batch testing. We use custom test jigs to verify every protection feature of the BMS, check the cell balance, and confirm the capacity meets the specification. The results are logged against the pack’s unique serial number for full traceability.

The Importance of Traceability and Documentation

In the event of a field issue, an OEM needs to be able to quickly identify the scope of the problem. This is where traceability is paramount. Every battery pack we produce has a unique serial number. Tied to that serial number in our manufacturing execution system (MES) is a complete history of its production: the batch numbers of the cells and BMS used, the specific production line and date, and the complete electronic record of its final QC test. If you report an issue with a single unit, we can use this data to immediately quarantine and inspect any other units from the same production batch, providing rapid containment and peace of mind.

4. How Do You Manage Your Supply Chain for Critical Components?

Recent global events have exposed the fragility of complex supply chains. A shortage of a single, tiny semiconductor can bring a multi-million dollar product line to a halt. As an OEM, you need a battery partner who is not just a manufacturer but also a sophisticated supply chain manager.

Building Resilience Through Strategic Sourcing

Our approach to supply chain management is built on long-term partnerships and risk mitigation. For the most critical components—the lithium cells and the BMS ICs—we have spent years building deep relationships with the industry’s top-tier suppliers. These are not transactional relationships; they are strategic alliances. This gives us priority access to allocation during shortages and better visibility into their technology roadmaps.

A Multi-Tiered Approach to Supplier Management

We don’t rely on a single source for everything. Our strategy is tiered:

Tier 1 (Cells, ICs): Long-term, strategic partnerships with top brands. We carry buffer stock for our key OEM clients based on their forecasts.
Tier 2 (MOSFETs, Connectors): We qualify and maintain relationships with at least two to three pre-approved suppliers for these components. This provides redundancy and protects against single-supplier disruptions.
Tier 3 (Passive Components): We use a broad base of qualified suppliers to ensure competitive pricing and availability.

This proactive, multi-layered approach is designed to create a resilient supply chain that can weather market volatility and protect your production schedule.

5. What Does Your Project Management Process Look Like for a New OEM Client?

As an OEM, you have an established New Product Introduction (NPI) process. Your battery supplier must be able to integrate seamlessly into that process. A lack of a structured project management framework is a major red flag and often leads to miscommunication, missed deadlines, and scope creep.

The Role of the Dedicated Project Manager and Application Engineer

To prevent this, we assign a dedicated team to every new OEM project:

A Project Manager (PM): Your single point of contact for all commercial and scheduling issues. The PM is responsible for the overall project timeline and communication.
An Application Engineer: Your technical counterpart. This engineer works directly with your R&D team to define the technical specifications, provide DFM feedback, and resolve any integration challenges.

This two-person team structure ensures that communication is always clear and that both the commercial and technical aspects of the project are managed professionally.

A Phased Approach from Concept to Mass Production

We follow a formal phase-gate process that aligns with most corporate NPI workflows.

OEM Project Lifecycle at Hanery

Each phase has specific deliverables and requires a formal sign-off from your team before we proceed to the next. This structured approach ensures there are no surprises and that all stakeholders are aligned at every stage of the development process.

6. How Do You Protect Our Intellectual Property (IP) and Ensure Confidentiality?

For an established brand, your product designs are your most valuable asset. The risk of IP leakage is a serious concern when partnering with any external supplier. You need a partner who has both the legal frameworks and the corporate culture to protect your confidential information rigorously.

Going Beyond a Standard NDA with a China-Specific NNN Agreement

As we’ve highlighted before, a standard Western-style NDA is often difficult to enforce in China. The correct legal tool is a Non-Disclosure, Non-Use, and Non-Circumvention (NNN) Agreement. This agreement, which we readily sign with our OEM partners, is specifically designed to be enforceable in Chinese courts. Its “Non-Use” clause is particularly critical, as it contractually forbids us from using your IP for any purpose other than manufacturing your product.

Implementing Physical and Digital Security Protocols

Legal agreements are essential, but they must be backed by robust internal security practices. At Hanery, we implement multiple layers of security:

Digital Security: All OEM project files are stored on a separate, access-controlled server. Access is granted only to the specific engineers and project managers assigned to your project.
Physical Security: Our R&D and OEM-dedicated production areas have restricted access. We do not allow unauthorized personnel or personal mobile devices in these zones.
Culture of Confidentiality: Ultimately, our best security is our business model. We are a long-term OEM partner, not a company looking to launch our own consumer brand. Our reputation and the trust of our clients are our most valuable assets, and we have no interest in jeopardizing them.

7. What Is Your Process for Failure Analysis and After-Sales Support?

Even with the best manufacturing processes, field failures can occasionally happen. For an OEM, how your supplier responds in these situations is a true test of the partnership. A simple “replace the faulty unit” policy is not sufficient. You need a partner with the deep engineering capability to find the root cause of the failure and ensure it never happens again.

Implementing a Formal 8D Problem-Solving Process

When an OEM partner reports a confirmed field failure, we don’t just offer a replacement. We initiate a formal 8D (Eight Disciplines) problem-solving process. This is a rigorous, data-driven methodology used by top-tier manufacturers to identify, correct, and eliminate recurring problems.

The process involves:

Forming a dedicated engineering team.
Describing the problem in detail.
Implementing a temporary containment action.
Identifying and verifying the root cause.
Developing and verifying permanent corrective actions.
Implementing the permanent corrective actions.
Preventing the problem from recurring.
Congratulating the team.

We provide our OEM partner with a full 8D report, detailing our findings and the steps we have taken in our production process to prevent a recurrence.

The Value of a Local or Regional Technical Support Presence

While our main engineering team is in China, we understand the need for timely support. We have established regional technical liaisons who can provide first-level support in our clients’ time zones, facilitating faster communication and diagnosis.

8. How Do You Help Us Manage the Total Cost of Ownership (TCO)?

As an OEM, you are under constant pressure to manage costs. However, a focus on the unit price alone can be misleading. A true partner will work with you to optimize the Total Cost of Ownership (TCO) of the battery system across its entire lifecycle.

Design for Manufacturability (DFM) and Cost-Down Initiatives

Our engineering collaboration starts with Design for Manufacturability (DFM). We analyze your product design and suggest ways to make the battery integration more efficient, which can reduce your own labor costs during final assembly. Furthermore, we engage in proactive cost-down initiatives. For example, after a product has been in the market for a year, we might propose switching to a new, more cost-effective BMS IC that offers the same performance, sharing the savings with our partner.

The Financial Impact of Higher Cycle Life and Reliability

The biggest TCO savings often come from the battery’s long-term performance. A battery pack that has a higher cycle life means your product will last longer in the field, enhancing your brand’s reputation for quality. More importantly, higher reliability means lower warranty reserves, fewer product returns, and reduced customer support costs. These “hidden” savings, which we build into our products through quality design, are a significant contributor to your product’s overall profitability.

9. What Are Your Capabilities for Managing Global Logistics and Compliance?

Your business is global. You may have contract manufacturers in Southeast Asia, distribution centers in Europe, and service centers in North America. Your battery partner must have the expertise and infrastructure to reliably deliver your products anywhere in the world, in full compliance with complex international regulations.

Expertise in Class 9 Dangerous Goods (DG) Shipping

Shipping lithium batteries is a specialized skill. As Class 9 Dangerous Goods, they are subject to strict IATA (air) and IMDG (sea) regulations. Errors in packaging, labeling, or documentation can lead to massive fines and your shipments being impounded. We have a dedicated in-house logistics team that specializes in DG shipping. We manage the entire process, ensuring every shipment is 100% compliant.

Providing a "Turnkey" Logistics Solution (DDP)

We have the experience to ship to your facilities or your partners’ facilities globally. For many of our OEM clients, we provide a full DDP (Delivered Duty Paid) service. This is the ultimate turnkey logistics solution. We handle:

Compliant DG Packaging and Labeling
All Export and Import Documentation
Booking with Qualified Freight Carriers
Customs Clearance in the Destination Country
Payment of All Duties and Taxes
Final “Last-Mile” Delivery to Your Specified Address

This seamless service allows your logistics team to focus on managing your finished goods, not on the complexities of sourcing and transporting a critical component from overseas.

Frequently Asked Questions

What is your typical PPM (Parts Per Million) defect rate for OEM projects?

Our internal target for mature products is well below 500 PPM for field failures within the warranty period. We track this metric for all our OEM partners and use it as a key indicator for our continuous improvement programs.

How do you handle Engineering Change Orders (ECOs) mid-project?

We have a formal ECO process. Your requested change is reviewed by our engineering team for feasibility, and we provide a clear assessment of the impact on cost, timeline, and performance. No changes are implemented without a formal, signed ECO from your team.

Can you place our company’s logo and part numbers on the battery packs?

Yes, absolutely. As an OEM partner, we customize the labeling to meet your branding and traceability requirements, including logos, part numbers, serial numbers, and any required regulatory markings.

Do you provide support to our contract manufacturer (CM) during the NPI phase?

Yes. Our application engineers can communicate directly with your CM’s engineering team to provide integration support, answer technical questions, and ensure a smooth transition into mass production.

What is your standard warranty for OEM battery packs?

Our standard warranty is 12 months from the date of manufacture. However, for specific OEM projects with well-defined operating conditions, we can work with you to develop a warranty that aligns with your final product’s warranty period.

Can we consign specific components (e.g., a proprietary connector) to you for assembly?

Yes, we can accommodate this. We have a formal process for managing customer-consigned materials, ensuring they are properly received, inspected, stored, and integrated into your battery packs.

What are your disaster recovery and business continuity plans?

We maintain a comprehensive business continuity plan that includes data backups, redundant critical equipment, and a qualified secondary supplier base for non-proprietary components to minimize disruption from unforeseen events.

How do you ensure the raw cells you source are “Grade A”?

We source directly from top-tier cell manufacturers with whom we have long-standing relationships. Furthermore, our rigorous IQC process involves testing a sample of every incoming batch for key parameters like capacity, internal resistance, and self-discharge to verify they are genuine, Grade A cells that meet our specifications.

Can we get exclusivity on a custom-designed battery pack?

Yes. For any battery pack that is designed specifically for your product, our NNN agreement ensures that the design is your exclusive IP. We will not sell or market that specific design to any other customer.

How do you stay current with evolving battery technology and regulations?

Our R&D team is constantly evaluating new cell chemistries and BMS technologies. We are also active members of industry associations, which keeps us informed about the latest developments in safety standards and transportation regulations globally. We proactively advise our OEM partners on how these changes might impact their products.

Conclusion: Selecting a Partner to De-Risk Your Brand and Supply Chain

For an OEM, selecting a Li-Po battery supplier is one of the most consequential decisions in the product development lifecycle. A misstep can lead to quality issues that tarnish your brand’s hard-won reputation, and supply chain disruptions that can cripple your ability to meet customer demand. The choice must go far beyond a simple comparison of unit prices.

By asking these nine tough, operational questions, you can probe a potential supplier’s true capabilities. You are looking for a partner that demonstrates a deep commitment to quality through robust systems, the capacity and flexibility to scale with your business, the engineering depth to act as a true collaborator, and the professionalism to protect your interests. Choosing the right partner is a strategic act of de-risking your business. It is an investment in consistency, reliability, and a resilient global supply chain that will support your brand’s growth for years to come.

If you are an OEM looking for a battery manufacturer that can confidently and transparently answer these questions, we invite you to speak with our team. Let us show you how a true manufacturing partnership can become your competitive advantage.

References

International Organization for Standardization. “ISO 9001 and related standards.” Accessed via https://www.iso.org/iso-9001-quality-management.html
Harvard Business Review. “Building Resilient Supply Chains.” May 2020.
World Intellectual Property Organization (WIPO). “Protecting your IP in China.”
American Society for Quality (ASQ). “What is 8D (Eight Disciplines)?” Accessed via https://asq.org/quality-resources/eight-disciplines-8d
International Air Transport Association (IATA). “Lithium Battery Shipping Regulations (LBSR).”
Underwriters Laboratories (UL). “UL 2054 – Standard for Household and Commercial Batteries.”
International Electrotechnical Commission. “IEC 62133-2:2017 – Safety requirements for portable sealed secondary cells.”
M. G. Pecht, et al. “Supply Chain Management for the Electronics Industry.” CRC Press, 2004.
U.S. Consumer Product Safety Commission (CPSC). “Recalls.” Accessed via https://www.cpsc.gov/Recalls
International Chamber of Commerce. “Incoterms® 2020.”

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