The Battery Upper Base Assy is an integrated aluminum structural assembly that forms the upper mounting plane for EV battery modules, and often serves as the interface between the battery pack's internal structure and its top cover or lid. Unlike a single-piece extrusion or plate, this assembly combines multiple aluminum components — extruded rails, machined crossmembers, and welded brackets — into one qualified sub-assembly delivered ready for line-side installation.

Manufactured from high-grade 6000-series aluminum extrusions and precision-cut sheet, the upper base assembly is engineered to hold battery modules securely from above, distribute vertical and lateral loads, and provide fixed mounting points for busbars, wiring harnesses, and thermal management components. Depending on the pack architecture, it may also function as a compression plate or a rigid tie-bar across the top of the module stack. All components are joined via robotic welding or structural fasteners, then CNC-machined as a complete assembly to guarantee hole-pattern accuracy and flatness across the entire unit.
Shengxin delivers this assembly fully inspected and, if specified, surface-finished — anodized or powder coated — so it arrives at your production line ready for immediate integration. Our aluminum battery structural component capabilities cover the full value chain: from extrusion die design and profile production to welding, machining, and surface treatment under one roof.
Features & Benefits
-
True assembly delivery: All extrusions, brackets, and welded joints are assembled and inspected before shipping — no kitting or in-house assembly required on your side.
-
Multi-component integration: Designed to combine upper crossmembers, longitudinal rails, and mounting tabs into one cohesive structure, reducing part count and assembly time.
-
High flatness and precision: Post-weld CNC machining ensures mounting surfaces and hole positions meet ±0.2 mm flatness and positional tolerances across the entire assembly envelope.
-
Weight-optimized profiles: Hollow and ribbed extrusion geometries provide stiffness where needed while shaving kilograms off the upper structure — contributing to overall EV range.
-
Surface-ready delivery: Available with anodized, powder coated, or wet-painted finishes applied after assembly, ensuring full coverage even at weld seams.
-
Validated weld integrity: Robotic welding with parameter monitoring and periodic destructive testing ensures consistent joint strength for structural reliability over the vehicle lifetime.
Technical Specifications
|
Material
|
Al 6005A / 6061 / 6063 extrusions & plates (T6)
|
|
Assembly Type
|
Welded sub-assembly with optional mechanical fasteners
|
|
Welding Process
|
Robotic MIG/TIG, weld parameter logging
|
|
Post-Weld Machining
|
CNC milling & drilling on assembly-level fixture
|
|
Flatness
|
≤0.2 mm per 300 mm (assembly datum surface)
|
|
Surface Finish
|
Anodized (clear/black), powder coated (full RAL), PVDF
|
|
Application
|
Upper module support, lid interface, top compression plate
|
Where the Upper Base Assy Fits in Your Battery Pack
In a typical EV battery pack, structural components are layered. This diagram shows conceptually how the Battery Upper Base Assy interfaces with other pack elements — and which Shengxin products can support each layer.
|
Layer
|
Component
|
Related Shengxin Product
|
|
Top Cover / Lid
|
Sealed enclosure lid
|
Custom aluminum sheet fabrication
|
|
Upper Support (this product)
|
Battery Upper Base Assy
|
Current page
|
|
Module Retention
|
Side plates, module frames
|
Aluminum Battery Side Plate (custom)
|
|
Main Enclosure / Tray
|
Battery tray, front & rear bases
|
Aluminum Battery Trays, Battery Frontal Base, Battery Rear Base
|
By sourcing the Upper Base Assy alongside your tray and lower structural components from Shengxin, you ensure consistent material lot traceability, aligned tolerances, and a simplified supplier interface — all from one vertically integrated partner.
Customization Options for Battery Upper Base Assy
|
Parameter
|
Customization Range
|
|
Overall Dimensions
|
Per vehicle platform; length up to 2500 mm
|
|
Component Mix
|
Rails, crossmembers, gussets, busbar mounts — defined per your BOM
|
|
Joining Method
|
Welded, riveted, or hybrid (structural adhesive + mechanical)
|
|
Integrated Features
|
Threaded inserts, studs, cable clips, thermal pad recesses
|
|
Surface Treatment
|
Anodizing, powder coat, PVDF — applied post-assembly
|
Why Shengxin for Your Battery Upper Base Assembly?
Assemblies demand more than just good components — they demand integrated manufacturing discipline. Shengxin’s 29-year track record in aluminum extrusion and fabrication provides the process control needed to deliver complex welded assemblies with repeatable quality.
One-Stop, One Responsibility
Extrusion, welding, machining, and finishing all happen within Shengxin’s facility — no subcontractor hand-offs, one quality system, one point of contact.
Assembly-Level Fixturing
We design and build dedicated welding and machining fixtures for your upper base assembly, ensuring every unit meets dimensional specifications without variation drift.
100,000-Ton Annual Capacity
From a single prototype to multi-thousand-unit production runs, our 35 extrusion lines and 5 container loading platforms scale with your program.
International Certifications
Compliance with GB5237, Qualanod, BS3987, JIS H8601, EN755, EN12020. We support PPAP submission with full dimensional reports and material certs.
Global Shipping Expertise: We export to 97 countries, with custom packaging designed to protect large welded assemblies during transit. All shipments are container-optimized from our 5,000-ton warehouse with dedicated loading bays.
Battery Upper Base Assy FAQ
Q: What exactly is included in a “Battery Upper Base Assy”?
A: It typically includes longitudinal rails, crossmembers, mounting brackets, and integrated fasteners or threaded holes — all welded or assembled into a single part number. The exact content is defined by your design; we work directly from your BOM and drawings.
Q: Do you deliver the assembly with fasteners and inserts already installed?
A: Yes. Helicoils, PEM-style inserts, studs, or pressed-in nuts can be installed during production, so the assembly arrives ready to bolt onto your pack without additional operations.
Q: How do you ensure alignment between the upper base and the main battery tray?
A: We strongly recommend manufacturing the main battery tray and the upper base assembly within the same supply chain. Shengxin can produce both, using a common datum strategy and matched machining fixtures, guaranteeing alignment of all mounting interfaces.
Q: Can you perform leak testing or dimensional scanning on the finished assembly?
A: While the upper base is not typically a sealed component, we can provide CMM reports, 3D scanning data, and if required, coordinate with leak-test requirements for the complete pack enclosure when we supply the full set of structural parts.
Q: What if our design changes during prototype phase?
A: We support iterative prototyping. Our engineering team manages revision control closely, and our in-house die shop and machining capability allow us to turn revised components quickly — typically within 2–3 weeks for a modified upper base assembly prototype.
← Back to Aluminum Battery Trays product category
| Related components: Battery Frontal Base, Battery Rear Base