Building a Secure, Self-Service Charging Solution for Correctional Facilities
- David McClurg
- May 26
- 3 min read
Updated: May 27
Correctional facilities increasingly rely on connected devices to support inmates with external communication, and continuing education. For one of our clients, these devices, including rugged smartphone-like and tablet-like devices, played a critical role in helping inmates stay connected with family members and access educational resources while incarcerated.
As adoption grew, however, so did the operational challenges.
The Challenge
Initially, device charging was handled manually by correctional staff. Guards were responsible for collecting every device, connecting each one to a charger, monitoring the charging process, and redistributing devices afterward.
While manageable at a small scale, this process became increasingly inefficient as facilities expanded their device programs. Staff time was consumed by repetitive handling procedures, and devices were often unavailable to inmates for extended periods while waiting to be charged.
The growing operational burden created several challenges:
Increased workload for correctional staff
Limited scalability for larger facilities
Reduced device availability for inmates
Lower utilization and revenue from the device ecosystem
Greater logistical complexity surrounding charging and tracking
The client needed a secure, scalable solution that would allow inmates to charge their own devices while maintaining strict validation and security requirements.
Designing an Automated Charging Station
To solve this problem, we developed a fully integrated automated charging station specifically designed for use in correctional facilities.
The system combined custom mechanical, electrical, and software engineering into a single ruggedized product capable of operating reliably in demanding environments with minimal staff intervention.
The charging station was built around a custom-designed steel enclosure engineered for wall-mounted installation inside correctional facilities. The enclosure included design considerations focused on:
Durability and tamper resistance
Ease of installation and maintenance
Secure device storage during charging
Reliable long-term operation in high-use environments
Secure Device Validation and Check-In
At the core of the system is a Linux-based control platform that manages authentication, charging, and device security.
Using the station’s touchscreen interface, inmates check in their device using a unique ID and PIN. RFID validation ensures the correct device is associated with the correct user before charging begins.
Once authenticated:
An available charging slot unlocks
The inmate inserts the device
The system verifies proper insertion and device identity
The compartment automatically locks
Charging begins securely
When charging is complete, the inmate can retrieve the device using the same credentials.
Remote Management and Diagnostics
Beyond basic charging functionality, the system also supports advanced remote management capabilities.
The charging stations communicate over Wi-Fi to:
Validate inmate credentials through external APIs
Upload diagnostic and operational data
Receive remote software updates
Enable remote troubleshooting and maintenance
This connectivity allows facility operators and administrators to monitor system health while reducing on-site support requirements.
Solving the Retrofit Challenge
One of the most technically demanding aspects of the project involved integrating charging functionality into the client’s existing device housings.
Because the devices were already deployed in rugged custom enclosures, redesigning the entire hardware platform was not practical. Instead, we engineered a retrofit solution that preserved compatibility with the existing devices.
Our team developed a custom flexible printed circuit board (PCB) that connected the device’s charging circuitry to the enclosure screws. These screws then served as charging contact points when inserted into the station.
To protect the retrofit hardware from tampering and environmental wear, we also designed a custom protective plastic cover integrated into the device housing.
This approach allowed the client to upgrade existing devices without replacing their installed hardware fleet.
Full-Service Product Development
What made this project especially unique was the breadth of engineering disciplines involved. From concept through deployment, our team delivered:
Mechanical design
Electrical engineering
Embedded Linux software development
RFID integration
API and networking integration
Manufacturing support
Retrofit hardware design
By handling the entire product lifecycle internally, we were able to rapidly iterate with the client and adapt the design as new requirements emerged throughout development.
Results
The final solution provided the client with a cost-effective, scalable charging platform that significantly reduced operational overhead for correctional staff while improving device availability for inmates.
Most importantly, the automated charging system enabled the client to expand into larger correctional facilities that would have been difficult to support using manual charging processes alone.
The project demonstrates how integrated hardware and software engineering can transform operational bottlenecks into scalable infrastructure solutions.
