Case Studies

Sustainable Battery Housings Made from Recycled Plastic Instead of Aluminum

How NAEXT improved insulation properties by switching to 100% recycled plastic while simultaneously reducing weight, costs, and CO₂ emissions.

About NAEXT

NAEXT is a German manufacturer of sustainable energy storage systems. The company uses so-called second-life batteries from electric vehicles, refurbishes them technically, and reuses them in stationary storage systems. The goal is to extend the lifespan of existing resources and actively contribute to the energy transition.

Application

Battery housings / protective covers

Industry

Electronics

Material

100% recycled ABS

Post-processing

CNC milling

Container mit Batteriegehäusen

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Thumbnail Case Study formary x NAEXT

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This project demonstrates the potential of switching materials from aluminum to plastic: A heavy, energy-intensive aluminum component was replaced by a fully recycled plastic solution—with advantages in insulation properties, weight, cost, handling, and sustainability. At the same time, the project was successfully transitioned into series production despite very tight timelines.

Project Overview

Objective: Develop a sustainable, lighter, and more cost-efficient alternative to aluminum battery housings with improved insulation and material properties
Challenge: High requirements for safety, dust and environmental protection, and material performance, combined with a very short time-to-market
Solution: Development of a two-part thermoformed solution made from 100% recycled ABS as a functional alternative to aluminum
Result: Significantly reduced weight and material costs, improved insulation properties, and a quickly available, production-ready solution

The Problem

Sustainable Energy Storage with Inefficient Components

NAEXT follows a consistently sustainable approach: batteries from electric vehicles are given a second life in stationary energy storage systems. However, a key inconsistency became apparent during the project: the protective covers used were made of primary aluminum.

These components are heavy, expensive, and energy-intensive to produce—contradicting the overall sustainability goals of the system.

Batteriegehäuse aus Aluminium

The Challenge

Replacing a Heavy, Cost- and Energy-Intensive Aluminum Component Under Tight Deadlines

NAEXT set out to align the protective covers of their energy storage systems with their sustainability standards by replacing the existing aluminum housing with a more efficient and resource-saving alternative. The requirements for the new solution were clearly defined and technically demanding:

Protection against contact with live components
Dust and environmental protection for safe operation
High insulation performance
Low weight for easier handling
Use of sustainable (recycled) materials
Very short development and delivery timelines

The Solution

Design and Manufacturing Optimization via Thermoforming and Combination Tooling

Together with NAEXT, formary developed a completely new housing solution, consistently replacing aluminum with recycled plastic. The design was optimized so that:

✓ The lid and base could be produced using a single combination tool

✓ Only one tool is required

This reduced both production time and investment costs. At the same time, a second variant was implemented at short notice, also made from 100% recycled ABS. To meet the tight schedule, a regional production partner with immediate capacity was integrated via the formary supplier network, enabling development and manufacturing without delays.

Batteriegehäuse aus Kunststoff

The Advantage

Short Distances for Maximum Speed and Coordination

By selecting a production partner located near NAEXT’s site, prototypes could be reviewed locally, picked up in person, and directly integrated into the application. Changes and iterations were implemented without delay.

The result: maximum implementation speed combined with high quality and close coordination among all parties involved.

Material Change

A Key Lever for Cost, Performance, and Sustainability

Switching from aluminum to recycled plastic delivered multiple benefits:

✓ Significantly lower weight

✓ Improved technical properties

✓ Easier handling in daily use

✓ Reduced manufacturing energy

✓ Lower costs

Innere Ansicht des Batteriegehäuses aus Kunststoff

Henning Behn, Geschäftsführer von NAEXT

“It was very important to us to have a supplier who would support us right from the start of this development, and that’s exactly what we found in formary.”

— Henning Behn, NAEXT

The Result

Sustainable, Scalable, and Successfully Transferred to Series Production

The jointly developed housing components are now an integral part of NAEXT’s energy storage solutions. The project created a strong foundation for scalable future development.

Key success factors included:

Fast implementation despite tight timelines
Transferability to additional variants
Combination of design expertise, supplier network, and manufacturing competence

Mr. Behn adds:

“The combination of technical expertise, regional network, and fast responsiveness made this project so straightforward to implement.”

Container mit Batteriegehäusen aus Kunststoff in seitlicher Ansicht

FAQ – Frequently Asked Questions About Battery Housings & Material Substitution

Why use plastic instead of aluminum for battery housings?

Plastic—especially recycled material—can be produced much more energy-efficiently and allows for lighter components.

What are the advantages of thermoforming plastic for housings?

Is recycled plastic suitable for industrial applications?

How quickly can such projects be implemented?

Further Content

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Replacing Aluminium with Plastic: When Is It Worth It?

Aluminium is the standard material in many technical applications. And for good reason: the material offers high strength, corrosion resistance and is well established across numerous industries. Nevertheless, in certain cases, it is worth considering a material change. This is particularly true when weight, electrical insulation, corrosion behaviour, costs or functional integration play a central role. The key point is this: aluminium cannot simply be replaced 1:1 with plastic. This article explains when thermoformed plastic parts can be a suitable alternative to aluminium, where the limitations lie and which factors are decisive in the evaluation.

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Metals and plastics are two essential material categories used across various industries and applications, from consumer goods manufacturing to the production of technical components.

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What is Recyclate? Options in Plastic Recycling and Distinction from Virgin Material

In an increasingly sustainability-oriented world, recycling and the reuse of materials play a key role. Plastic recyclates offer a sustainable alternative to virgin materials. But what exactly does the term mean, and how can recyclates be distinguished from virgin materials? Read more now.

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Plastic Compounds Explained Simply: How Additives Turn Standard Plastics into True High-Performance Materials

In practice, plastics are rarely “pure.” Their properties are specifically tailored to meet specific requirements. This is exactly where plastic compounds come into play. When you develop or procure plastic parts, compounds significantly influence function, cost, and quality. They determine whether a component is robust, UV-resistant, or electrically conductive. Read more in this article.

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What Are Plastic Additives? Functions & Properties Explained

Plastics alone rarely meet all the requirements of industrial applications. It is only through the use of specific additives that materials become robust, flexible, or durable. This is exactly where additives come into play. They specifically alter the properties of plastics, making them suitable for specific applications in the first place.

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Moritz Bitter - Co-Founder

Co-Founder

Moritz Bittner