Stamped Aluminum Battery Housing Cuts 35% of Enclosure Weight

Maxion Structural Components and Novelis have jointly developed Maxion InVolt, a battery housing for electric buses and trucks stamped from rolled aluminum using a purpose-built alloy, which the companies say is about 35% lighter than an extruded aluminum housing meeting the same technical requirements.

Maxion Structural Components and Novelis have put a number on one of the least glamorous problems in electric trucking: the box that holds the battery. The two companies say their jointly developed enclosure, called Maxion InVolt, is roughly 35% lighter than an extruded aluminum housing built to the same technical requirements, according to the announcement carried by Charged EVs.

The change is in how the metal is formed. Instead of extrusion — pushing aluminum billet through a die to create long profiles that are then cut and welded into a frame — InVolt is stamped from rolled aluminum sheet, using an alloy Novelis created specifically for the application. Stamping presses flat sheet into shape between tools, the same basic process that produces car body panels.

Why a battery box is worth redesigning

On a heavy commercial vehicle, the enclosure is not a trivial component. It has to be structurally stiff enough to carry several tonnes of cells through years of road loading, sealed against water and dust, able to contain a thermal event, and mounted in a way that survives crash requirements. Those demands push designers toward thick sections, which is why extruded profiles have been the default: they deliver stiffness in a straight line and are easy to bolt or weld together.

The penalty is mass. Extruded frames tend to carry material where the geometry demands it rather than where the load actually is. Stamped sheet, if the alloy will tolerate the forming, allows the wall thickness and the shape to be tuned continuously across the part — ribs and beads where stiffness is needed, thin skin where it is not. That is the mechanism behind the 35% figure the two companies are quoting.

For a bus or a Class 8 truck, weight taken out of the structure is weight that can be returned either as payload or as cells. Fleet operators buy on cost per mile and on how much freight or how many passengers a vehicle can legally carry. A lighter enclosure does not directly change either number in a way the companies have quantified, but it moves the design budget in the operator's favor rather than the engineer's.

Stamping changes the manufacturing economics

The second consequence is industrial rather than physical. Extruded enclosures are assembly-intensive: profiles are cut, machined, then joined with long weld runs, and every weld is a potential leak path in a sealed box that has to keep an IP rating for the life of the vehicle. Stamping consolidates parts. Fewer pieces means fewer joints, less fixturing, and shorter cycle times once the tooling is paid for.

That last clause is the trade. Stamping tools are expensive up front and are specific to a geometry, whereas extrusion dies are comparatively cheap and a profile can be cut to any length. The stamped route therefore rewards volume. It is a bet that electric bus and truck programs are moving out of the pilot phase and into runs large enough to amortize hard tooling — which is a rather different statement about the market than a press release about a lighter part usually makes.

The companies say the design can be adapted, which points to a platform strategy: one tooling family serving several vehicle programs with variations in footprint and cell layout, rather than a bespoke enclosure per customer.

What it means for aluminum demand

Novelis is a rolled-aluminum producer, and rolled sheet is a higher-value, more specified product than commodity extrusion billet. An application that requires a purpose-designed alloy — formable enough to stamp, strong enough to carry a battery pack, weldable and corrosion-resistant — is exactly the kind of demand a rolling business wants, because it is hard to substitute and it sits inside a qualified vehicle program for years.

Battery enclosures are also physically large. A single heavy-duty pack housing consumes far more metal than a body panel, so each program win carries meaningful tonnage. For Maxion, whose structural components business has historically been anchored in wheels and chassis parts for internal-combustion trucks, the enclosure is a route into the electric drivetrain that uses the same core competence — forming and joining metal at scale.

What is not yet on the table

Neither company has published a cost figure, a production date, a named customer, or a tonnage estimate, and none should be inferred. The 35% claim is a comparison against an extruded housing built to the same technical requirements — a like-for-like engineering benchmark, not a comparison against every enclosure on the road. Steel enclosures, composite designs and cell-to-chassis architectures that dispense with a discrete housing altogether are all competing for the same space.

The signals worth watching are ordinary industrial ones: whether a truck or bus OEM is named, whether the alloy is qualified beyond a single program, and whether the tooling is installed at a plant with capacity for more than one customer. Those are what turn a jointly developed part into a supply position.

The market backdrop

The announcement landed on a soft session for US equities. As of the last trade at 20:00 GMT on Tuesday, September 1, 2026, the S&P 500 tracker SPY was at $761.72, down 0.69% from a previous close of $767.05, with a day range of $759.48 to $764.67. The Nasdaq 100 proxy QQQ was weaker at $707.77, off 1.25% against a prior close of $716.76 and trading between $704.66 and $712.30. The Dow 30 tracker DIA sat at $527.75, down 0.72% from $531.57.

None of that reflects the enclosure news, and it is not meant to. But it frames the environment in which commercial-vehicle electrification suppliers are asking customers to commit to hard tooling: risk appetite on the day was pointed the other way, with the tech-heavy index down roughly twice as much as the broad market. Programs that require capital before revenue get scrutinized hardest in exactly those conditions.

The engineering argument here is clean enough — take a third of the weight out of a structural part without relaxing its requirements and every downstream number improves. Whether that becomes volume depends on how many electric bus and truck programs reach the scale that stamping needs.

Key facts

• Product: Maxion InVolt battery housing for electric buses and trucks
• Weight saving: About 35% lighter than an extruded aluminum housing to the same technical requirements
• Process: Stamped from rolled aluminum using a new alloy created for the application
• Market backdrop: SPY $761.72 (-0.69%) as of 20:00 GMT, Sept. 1, 2026

Frequently asked questions

What is Maxion InVolt?

Maxion InVolt is a battery housing for electric commercial vehicles, developed jointly by Maxion Structural Components and Novelis. It is stamped from rolled aluminum using an alloy Novelis created specifically for the application, and it is aimed at electric buses and trucks. The companies say the design can be adapted across applications.

How much lighter is the InVolt housing?

The companies say the InVolt enclosure is about 35% lighter than an extruded aluminum housing built to the same technical requirements. That is a like-for-like engineering comparison against extrusion, not a claim against every enclosure design on the market, and no absolute weight in kilograms has been published.

What is the difference between stamped and extruded aluminum?

Extrusion pushes aluminum billet through a die to make long profiles that are cut and welded into a frame. Stamping presses flat rolled sheet into shape between tools. Stamping allows wall thickness and geometry to vary across the part, placing material only where loads require it, but it needs expensive dedicated tooling.

Why does battery enclosure weight matter for trucks and buses?

A heavy-duty battery pack housing has to be stiff, sealed, crashworthy and able to contain a thermal event, which pushes designers toward heavy sections. Weight removed from the structure can be returned as payload or as additional cells, both of which affect an operator's cost per mile and how much freight or how many passengers a vehicle can carry.

What does the partnership mean for Novelis?

Novelis produces rolled aluminum, and a battery enclosure is a large, high-specification part requiring a purpose-designed alloy. That kind of demand is harder to substitute than commodity metal and typically sits inside a qualified vehicle program for years. Each program win carries meaningful tonnage because enclosures consume far more metal than body panels.

Has a customer or production date been announced?

No. The announcement covers the joint development and the 35% weight comparison. No cost figure, production timeline, named vehicle manufacturer or volume estimate has been disclosed. The things to watch are whether an OEM is named, whether the alloy is qualified across multiple programs, and where the stamping tooling is installed.

Sources

• Maxion and Novelis develop InVolt aluminum battery housing for electric buses and trucks — Charged EVs

Photo: J E · Pexels Licence — source