Why Battery Mounting Details Matter More in Electric Vehicles 

Battery retention hardware has a thankless job. It rarely gets much attention in electric vehicle programs because it doesn’t move power, manage heat, or control performance. Yet, when batteries are mounted directly inside the chassis, the retention components that secure the batteries become an integral part of the vehicle’s structural system.  

These considerations are especially relevant for Harbinger Motors Inc. As a manufacturer of medium-duty electric vehicle chassis for commercial applications, such as walk-in vans, box trucks, and recreational vehicles, the company’s architecture and battery systems are designed for long service life under high-demand operating conditions.  

That’s why Harbinger partnered with MES as it moved into early production of its first chassis, to apply production-level discipline to a set of frame-mounted battery securing brackets.  

The lessons learned reflect how early manufacturing, coating, and quality discipline helped treat these components as production-critical from the very start.  

Why Battery Retention Brackets Demand Chassis-Level Consideration

Battery mounting brackets are typically low-complexity parts. But in this application, they function as the mechanical interface between the battery system and the chassis itself.   

Each bracket must do triple duty:  

1. Maintain precise alignment under load. 
2. Manage vibration. 
3. Hold position despite exposure to moisture, road debris, and corrosive environments. 

If bracket performance degrades, the result can be loss of alignment, increased vibration transfer, or added service complexity later in the vehicle’s life.  

To add even more complexity, the brackets were not interchangeable. This meant that multiple configurations were required based on mounting location within the chassis. This resulted in several distinct geometries and numerous part numbers. Some variants also incorporated secondary features, such as provisions for cable or wire retention, adding even more functional requirements.  

Because the battery packs are mounted inside the chassis, they cannot be treated as commodity brackets. Any variation in bracket geometry, machining accuracy, or coating performance has a direct impact on fit, assembly, and reliability.  

In addition to structural retention, some bracket variants also incorporated secondary features such as wire or cable clip mounting points. These multi-function requirements further increased design and manufacturing complexity, as features unrelated to load-bearing still had to meet dimensional and durability requirements without compromising structural performance.  

Lesson: Multiple variants and mounting locations required careful and strategic control across design, manufacturing, and quality planning. 

Why Manufacturing and Process Choices Matter

The brackets were forged to achieve the required strength and durability, then machined to meet alignment and fit requirements.   

Forging introduced additional risk beyond basic geometry. Variations in material flow and grain structure during the forging process could lead to internal stress or cracking if not tightly controlled. Once the forging was complete, those characteristics could not be fully corrected through machining, increasing the importance of early process control.  

Because these parts interface directly with the vehicle structure, small variations introduced during forging could not be fully corrected during later machining steps. Coating performance was also affected by initial process decisions, making process sequencing and control critical across all steps.  

Lesson: Treat forging, machining, and coating as a single production system. Early process decisions set constraints on corrective options later. 

Corrosion Protection Is a Performance Requirement

Because the brackets sit at the chassis level, they’re exposed to road salt, moisture, and debris. For this reason, corrosion resistance was a functional requirement rather than an appearance consideration.   

The coating system was required to meet extended salt spray performance targets consistent with exposure to snow, ice, and road salt environments. Coating performance was evaluated not only for corrosion resistance but also for its impact on dimensional fit across multiple bracket configurations.  

A dual coating approach was used to meet corrosion performance targets. Managing coating type, thickness, and consistency across variants was necessary to balance protection with fit and assembly requirements.  

Lesson: Coating selection and control should be defined early, since thickness and consistency affect both corrosion performance and assembly fit. 

What Early Discipline Prevented Later

None of this work was driven by a missed deadline or supply disruption. This approach reduced the risk of parts entering higher-level assembly with unresolved variation, which could have prevented completion of battery pack installation or required rework at the chassis level.  

The focus was on addressing complexity before it surfaced later in the process. By applying production level discipline early, MES helped Harbinger avoid common issues such as assembly interference, late-stage rework, coating-related fit problems, and reliability concerns during validation.  

Lesson: Early manufacturing and quality decisions on basic components reduce risk as production progresses. 

Where Quality Discipline Made the Difference

 As volumes increased and multiple bracket families moved through production, maintaining clarity across part numbers, tooling, and inspection criteria became critical to preventing mix-ups between similar components.  

Several specific quality practices helped ensure the manufacturing and process decisions translated into consistent performance as production progressed.  

1. Clear part family definition:
   Each bracket variant was treated as its own controlled part, with dedicated drawings, tooling references, and inspection criteria. 
2. Early dimensional validation:
   Key features affecting fit and alignment were validated early to reduce tolerance stack-up across forging, machining, and coating. 
3. Controlled coating thickness verification:
   Coating thickness was monitored to ensure corrosion protection without interfering with assembly or fastener engagement. 
4. Consistent documentation and traceability:
   Part numbers, revisions, and inspection records were kept aligned across suppliers and processes to prevent mix-ups as volumes increased. 
5. Production-ready approval standards:
   Quality validation was performed against production-level expectations rather than temporary pilot criteria. 

Conclusion 

Battery mounting components rarely draw attention, but when they interface directly with the chassis, their performance affects far more than basic assembly. In this case, early attention to manufacturing discipline, variant control, and corrosion protection helped establish a stable foundation for long-term reliability as production progressed.  

The takeaway is straightforward. Components that appear simple can carry system-level requirements, and addressing them early reduces risk later in validation, assembly, and scale up. 

Want to learn more about how MES supports early production programs by applying production-level discipline to structurally critical components? Contact us.  

Project Snapshot  

• Customer: Harbinger Motors Inc. 
• Industry: Electric vehicle manufacturing  
• Component: Frame-mounted battery retention brackets  
• Application: Securing battery packs inside the chassis frame  
• Manufacturing Process: Forging with precision machining and dual-stage coating  
• Material: 42CrMo4 chromium molybdenum steel  
• Part Weight Range: Approximately 2.6 kg to 4.1 kg per bracket  
• Variants: Multiple bracket configurations based on chassis mounting location  
• MES Scope: Sourcing, manufacturing coordination, coating management, and quality planning  
• Project Stage: Early production  
• Quality and Validation: AIAG Level 3 PPAP approval  
• Business Outcome: Established production-level consistency and reduced downstream risk during production ramp-up