1. Project Summary
Developed an innovative system for remote monitoring and charge management of electric vehicle fleets based on the Open Vehicle Monitoring System (OVMS). This solution enabled intelligent charge scheduling to take advantage of off-peak electricity rates while respecting facility power constraints, dramatically reducing operating costs while providing comprehensive telematics data through simple SMS commands.
2. Technical Solution Provided
Created a comprehensive EV fleet management system by modifying and extending the open-source OVMS platform with custom hardware and firmware components. The solution included a specialized control circuit board that interfaces between the OVMS device and vehicle charging systems, enabling remote charge enablement/disablement in response to scheduling parameters or direct commands. The system provides real-time GPS location tracking, battery status monitoring, and charge control through SMS messaging, allowing fleet managers to optimize charging strategies across multiple vehicles while accessing critical vehicle data from anywhere.
3. My Role & Contributions
I served as both the hardware designer and firmware developer for this specialized EV management system. My specific contributions included:
- Customizing the open-source OVMS firmware to handle SMS commands and charge control functions
- Designing a custom PCB that interfaces between the OVMS device and the vehicle’s charging system
- Implementing an efficient power management system that replaced the original linear supply with a switching design
- Developing firmware to control power states and optimize battery usage during long-term parking
- Creating CAN bus communication protocols to reliably extract vehicle information
- Integrating relay control circuitry for remote charge enablement/disablement
- Designing the complete system for reliable operation in automotive environments
4. Technical Challenges & Solutions
The primary challenge involved integrating with the vehicle’s charging system in a non-invasive manner that wouldn’t void warranties or compromise safety systems. By carefully analyzing the charging control circuits, I developed an interface that could safely interrupt and restore charging without modifying factory wiring or disturbing critical vehicle systems. This approach provided the necessary control while maintaining full compliance with vehicle specifications and safety requirements.
Power management presented another significant challenge, as the original OVMS device would drain the vehicle’s 12V battery during extended parking periods. I redesigned the power supply circuit using a high-efficiency switching regulator and implemented sophisticated sleep/wake firmware algorithms, reducing power consumption by over 80% while maintaining essential monitoring functions. This innovation allowed the system to remain operational for weeks without risking battery depletion.
5. Implementation Approach
The project followed an iterative prototyping approach, beginning with bench testing of the modified OVMS firmware and custom circuit designs. Development progressed through multiple hardware and firmware revisions, with each iteration addressing specific performance or reliability issues identified during testing. Field trials were conducted with a small subset of vehicles before full fleet deployment, allowing for real-world validation of both the hardware durability and the effectiveness of the charge management strategies under various conditions.
6. Results & Benefits
The deployed system successfully reduced fleet electricity costs by approximately 35% through intelligent charge scheduling that prioritized off-peak periods. The ability to distribute charging load across time prevented facility power overloads, eliminating the need for expensive electrical service upgrades. Fleet managers gained unprecedented visibility into vehicle status and utilization patterns through the SMS interface, while the improved power management eliminated instances of 12V battery depletion during extended parking.
7. Ongoing Support
Following deployment, I provided comprehensive documentation and training for fleet managers on system operation and maintenance. The modular firmware design allows for remote updates when new features are needed or when vehicle firmware changes require adaptations. I continue to provide occasional consulting support for system optimization and expansion as the EV fleet grows.
8. Technologies & Skills Applied
- Embedded firmware development
- Custom PCB design
- CAN bus communication
- Power management optimization
- SMS command processing
- GPS telemetry
- Automotive systems integration
- Open-source platform customization
- Relay control circuitry