An EV charging station has very different hardware requirements from a consumer tablet.

The screen may need to remain readable under direct sunlight, respond to gloved hands, and operate continuously inside a cabinet where heat, dust and other electronic components are present. At the same time, the computer behind the display may need to communicate with charging controllers, network equipment, payment devices and other peripherals.

That makes the touchscreen part of the charger architecture, not simply a screen installed in the front panel.

This is where Open Frame Tablets for EV Charging Stations become useful. An open frame industrial tablet can be integrated directly into the charging equipment, allowing the charger manufacturer to choose the display, touch panel, computing platform, interfaces and mounting method around the actual product design.

For EV charger OEMs and system integrators, that flexibility can be more important than simply having a powerful processor or a larger display.

Why Consumer Tablets Create Problems in Industrial Chargers

A consumer tablet is already a finished product.

It has a fixed enclosure, predefined mounting points, fixed connector positions and a thermal design intended for its original application. Those characteristics are convenient for personal use, but they can become limitations when the device has to be built into industrial equipment.

Consider a charger with a custom metal front panel.

The manufacturer may need the display to sit directly behind the panel, with only the active screen visible. The USB and network connectors may need to face a specific direction. The computer board may need to sit in a narrow space several centimeters behind the display.

A conventional tablet was not designed around those constraints.

An open frame tablet starts from a different premise: the hardware is intended to become part of another machine.

That gives the equipment manufacturer considerably more freedom over mechanical integration.

What Should an Open Frame Tablet Include?

There is no single configuration that fits every EV charger.

A small AC wallbox, a commercial AC pedestal and a high-power DC fast charger can have completely different requirements.

A typical industrial configuration may include:

These specifications should be treated as a starting point rather than a fixed product definition.

For an OEM project, the mechanical drawing, software requirements and environmental conditions should be established before the final hardware configuration is selected.

Display Brightness Is Only One Part of Outdoor Readability

Outdoor EV chargers have an obvious display problem: sunlight.

A standard indoor display can become difficult to read when direct sunlight reaches the screen. Increasing brightness can improve visibility, but brightness alone does not determine whether the display will perform well outdoors.

The optical stack matters.

Cover glass can create reflections. Surface treatment can reduce glare. The viewing angle affects how the image appears when the driver is standing away from the center of the screen.

The installation angle matters too.

A display facing the sky will experience a different optical environment from one installed vertically beneath a protective canopy.

There is also a trade-off that is often overlooked.

More brightness means more power consumption and potentially more heat.

That additional heat may not matter in an open indoor kiosk, but it can become significant inside a sealed EV charger cabinet.

The practical goal is therefore not to specify the highest possible brightness. It is to achieve sufficient visibility for the actual installation while keeping power consumption and thermal load under control.

Touch Performance Should Match the Charging Environment

The user interface of an EV charger needs to work under conditions that a smartphone does not normally encounter.

Drivers may wear gloves. The screen may have moisture on its surface. The equipment may be used repeatedly by people with very different touch behavior.

PCAP touchscreens are widely used for modern industrial interfaces because they provide a familiar user experience and support multi-touch interaction. For outdoor charging equipment, the touch configuration can also be adapted for glove operation.

The front glass deserves equal attention.

A charger installed in a public location may receive considerably more physical contact than a display inside a factory. Reinforced cover glass, appropriate thickness and surface treatment can therefore be part of the mechanical design rather than an afterthought.

There is no universal combination of glass, brightness and touch sensitivity that works for every charger.

The right configuration depends on how the charger is installed and how people are expected to use it.

Open Frame Design Gives OEMs More Mechanical Freedom

This is one of the strongest reasons to consider an open frame platform.

The charger manufacturer controls the enclosure.

The display does not need to bring its own complete housing because it can be mounted directly into the equipment structure.

This can simplify the front-panel design and eliminate unnecessary layers between the display and the charger enclosure.

It also makes customization easier.

An OEM may want a particular active display area while keeping the external dimensions of the charger unchanged. Another manufacturer may require a specific mounting hole pattern or connector location.

These requirements are much easier to address when the computing hardware is designed for embedded integration.

For products manufactured in multiple sizes, the same computing architecture can also potentially be adapted to different display configurations.

Choose Computing Power Based on the Software

A charging station does not automatically need a high-end industrial computer.

If the terminal is primarily responsible for the local user interface, basic system communication and a limited number of peripherals, a low-power ARM platform may be sufficient.

A more powerful ARM or x86 platform may be appropriate when the system runs complex graphics, multimedia, local databases, cameras, multiple applications or more demanding software.

RAM and storage should be evaluated in the same way.

A simple interface may not require a large amount of memory. A more complex application, especially one designed to support future software updates, may need additional headroom.

This is particularly relevant for equipment expected to remain in service for years.

The goal is not to maximize specifications.

The goal is to avoid paying for processing power that the application does not use while ensuring that the hardware remains capable of running the software throughout the planned product lifecycle.

Interfaces Often Matter More Than Processor Speed

For an industrial charger, the question is rarely just "How fast is the CPU?"

A more useful question is "What does the computer need to connect to?"

Depending on the system architecture, the tablet may communicate with:

charging control hardware;

energy meters;

payment terminals;

RFID or NFC readers;

network equipment;

cameras;

maintenance devices.

Ethernet is useful for stable wired networking. USB provides a convenient connection for peripherals. RS232 and RS485 remain relevant for industrial serial communication, while CAN may be required by a particular control architecture.

Wi-Fi and cellular connectivity provide additional options where a wired network is unavailable or undesirable.

The required interface combination should be determined before the motherboard is finalized.

Adding another communication port later is not necessarily a software modification. It can require changes to the board, connector layout, internal wiring and enclosure.

How OCPP Fits Into the Hardware Architecture

OCPP is an important part of connected EV charging systems.

The Open Charge Alliance defines OCPP as a standardized communication protocol between charging stations and central systems. OCPP 2.0.1 introduced broader functions covering areas such as device management, security, transactions and smart charging. OCPP 2.1 extends the protocol with additional capabilities, including functions related to bidirectional charging and energy management.

However, an Open Frame Tablet should not be confused with the OCPP controller.

The tablet is a computing platform.

It can run the local charging application and provide the user interface, while the charger controller and software architecture handle the functions assigned to them.

This distinction matters when selecting hardware.

An OEM should first determine where the OCPP software will run, which controller manages charging functions, and what data needs to be displayed to the user.

Once those decisions are clear, the tablet can be specified accordingly.

Thermal Design Can Affect the Hardware Selection

The internal temperature of an EV charger can be more important than the outdoor temperature.

A DC fast charger may contain power electronics that generate considerable heat. If the industrial tablet is installed inside the same cabinet, it becomes part of that thermal environment.

A processor that performs well on a test bench may not be the best choice when installed in a confined enclosure.

Lower-power hardware can sometimes provide a better balance between computing performance and heat generation. In other designs, additional thermal management may be required.

The display also contributes to the overall thermal load.

For that reason, thermal testing should ideally be performed with the tablet installed inside the actual charger cabinet.

Testing the tablet by itself does not reproduce the conditions of the finished product.

Environmental Requirements Depend on Where the Charger Is Installed

There is no universal definition of an "outdoor EV charger."

A unit inside a covered parking garage has different requirements from one installed beside a highway.

The following factors should be considered during hardware selection:

One important distinction is often missed: the tablet's environmental rating and the charger's overall protection are not necessarily the same thing.

The final enclosure, sealing method and installation design all contribute to the actual protection level of the complete charging station.

A Practical DC Fast-Charger Configuration

Consider a DC fast charger intended for a commercial parking facility.

The manufacturer wants a large interface that can be read easily from the front of the vehicle. The screen needs to remain visible during daylight operation, and the computer needs to communicate with the charger controller and network system.

A 13.3-inch or 15.6-inch Open Frame Tablet could be suitable, depending on the cabinet dimensions.

A possible configuration could include a high-brightness LCD, PCAP touch with glove support, reinforced cover glass, an Android or Windows platform, Ethernet and several industrial I/O ports.

The interface might display charging power, delivered energy, charging time, pricing and session status.

The touchscreen computer does not need to perform every charging function.

The charging controller manages the electrical process.

The backend manages network services.

The tablet provides the local interface and the computing functions assigned to it.

Keeping these responsibilities separated can simplify both software development and hardware maintenance.

What Should an EV Charger OEM Provide to the Hardware Manufacturer?

The more information available during the initial design stage, the less likely the project is to encounter expensive changes later.

A mechanical drawing is one of the most useful documents.

It should show the display opening, available installation depth, mounting points and the approximate location of cables and connectors.

The electrical specification should define power input and required interfaces.

The software team should identify the operating system, application requirements and communication architecture.

Environmental conditions should also be described as accurately as possible.

A useful specification includes:

This information gives the manufacturer enough context to recommend a platform rather than simply quote a standard tablet.

Why OEM/ODM Capability Matters

Customization becomes important when the touchscreen is part of the machine itself.

A standard tablet may be sufficient for a prototype demonstration. It becomes less attractive when the charger enters certification, mass production and long-term service.

The display may need to match a specific opening.

The connector position may need to change.

The processor may need to match existing software.

The touch panel may need to support gloves.

The cover glass may need a particular surface treatment.

Each of these changes can affect another part of the product.

This is where OEM/ODM manufacturing experience becomes valuable.

Hengstar develops industrial displays, industrial all-in-one computers and customized industrial computing hardware for equipment manufacturers, brands, distributors and system integrators.

For EV charging applications, the hardware can be configured around the customer's mechanical and electrical requirements, including display size, brightness, touch technology, cover glass, mounting method, processor platform, memory, storage, operating system and communication interfaces.

The objective is not to customize every component simply because customization is possible.

It is to build a stable hardware platform that fits the finished charging product.

From Prototype to Mass Production

The prototype stage should answer more than one question.

It should confirm that the tablet physically fits the charger, but it should also verify display visibility, touch response, thermal behavior, communication, power consumption and long-duration operation.

Testing inside the actual cabinet is especially important.

A tablet that performs well in a laboratory environment may behave differently when installed next to charging electronics.

Once the design is validated, production consistency becomes equally important.

An EV charger may remain in the field for many years. Replacing the computing platform later can affect mechanical dimensions, software compatibility, certification and thermal performance.

For this reason, long-term component planning and engineering change control are important parts of an OEM relationship.

The hardware supplier should be able to support not only the first prototype, but also the transition to volume production and subsequent product revisions.

The Best Open Frame Tablet Is the One That Fits the Machine

There is no universal "best" Open Frame Tablet for an EV charger.

The largest display is not always the right choice.

The fastest processor is not always the right choice.

The highest brightness is not always the right choice.

The correct configuration depends on the complete product.

Display brightness has to match the outdoor environment. Touch performance has to match the user's operating conditions. Processing power has to match the software. Interfaces have to match the control architecture. Mechanical dimensions have to fit the cabinet. Thermal performance has to remain stable during continuous operation.

This is the real value of Open Frame Tablets for EV Charging Stations.

Instead of adapting a consumer tablet to an industrial machine, the touchscreen computer can be developed around the machine itself.

For EV charger OEMs, that provides greater control over the user interface, internal architecture and long-term hardware platform. For ODM projects, it also creates more room to develop different charger models around a common industrial computing solution.

Frequently Asked Questions

What is an Open Frame Tablet for an EV charging station?

An Open Frame Tablet is an industrial touchscreen computing platform designed for embedded installation. It can be integrated into an EV charger instead of being used as a standalone consumer tablet.

Why are consumer tablets less suitable for EV chargers?

Consumer tablets normally have fixed enclosures, connector positions and mounting structures. These limitations can make mechanical integration, thermal management and long-term maintenance more difficult.

What screen size should an EV charger use?

The answer depends on the charger design and viewing distance. Common industrial configurations range from 7-inch compact interfaces to 15.6-inch larger terminals.

Can an Open Frame Tablet be used outdoors?

Yes. The hardware should be configured according to the installation environment, including brightness, glare, touch performance, temperature and environmental protection.

Can the touchscreen work with gloves?

Yes. PCAP touchscreens can be configured for glove-touch applications. Performance depends on the touchscreen design, glove material and environmental conditions.

Does an Open Frame Tablet need to support OCPP?

Not necessarily at the hardware level. OCPP belongs to the charging system's software and communication architecture. The tablet can provide the local computing platform for an application used within an OCPP-based system.

Can Hengstar customize an Open Frame Tablet for EV charging?

Yes. Depending on project requirements, customization can cover display size, brightness, touch technology, cover glass, mounting structure, computing platform, memory, storage, operating system and communication interfaces.

References

International Energy Agency (IEA), Global EV Outlook 2026 – Electric Vehicle Charging
https://www.iea.org/reports/global-ev-outlook-2026/electric-vehicle-charging-chap-6-and-10 

International Energy Agency (IEA), Global EV Outlook 2025 – Electric Vehicle Charging
https://www.iea.org/reports/global-ev-outlook-2025/electric-vehicle-charging 

Open Charge Alliance (OCA), OCPP Protocols
https://openchargealliance.org/protocols/ocpp-protocols/ 

Open Charge Alliance (OCA), OCPP 2.1
https://openchargealliance.org/ocpp-2-1-is-now-available/