OTA firmware updates (over-the-air) are remote software updates delivered to EV chargers over a network connection, without requiring a technician to visit the site. OTA updates enable charging operators and OEMs to efficiently deploy bug fixes, security patches, feature improvements, and configuration changes across a fleet of chargers, while maintaining reliability and compliance.
What Are OTA Firmware Updates?
OTA firmware updates involve transmitting new firmware to a charger over cellular, Ethernet, or Wi-Fi and installing it remotely.
– Firmware controls the charger’s core functions (power control, safety checks, communications, UI behavior)
– Updates can be scheduled and deployed in stages (pilot → region → full fleet)
– Success/failure status is reported back to the management platform
OTA updates are widely used for connected EV chargers that are managed by a CPMS.
Why OTA Firmware Updates Matter in EV Charging
Charging networks need long-term maintenance, security, and feature evolution.
– Fix bugs that cause failed sessions and improve uptime
– Patch vulnerabilities discovered through cybersecurity audits and monitoring
– Add features such as new tariff logic, better diagnostics, or protocol improvements
– Ensure compatibility with backend changes and evolving OCPP implementations
– Reduce operating costs by minimizing site visits and manual rework
For public networks and fleets, OTA capability is often a procurement requirement.
How OTA Firmware Updates Work
A robust OTA update flow typically includes:
– Release creation and validation in a secure update pipeline
– Firmware image signing and version control
– Deployment targeting (specific models, sites, regions, or serial ranges)
– Scheduled rollout during low-usage windows
– Charger download, integrity verification, and installation
– Post-update health checks and reporting
Good OTA systems also include:
– Rollback or dual-bank firmware to recover from failed updates
– Update throttling to avoid saturating network bandwidth
– Audit logs for compliance: who approved, when deployed, and what changed
OTA Updates Through OCPP
In many deployments, OTA updates are orchestrated via backend control and charger connectivity.
– The CPMS instructs chargers when and where to download updates
– Chargers report progress and final status codes
– Operators can pause or stop deployments if issues appear
OTA effectiveness depends on stable connectivity and correct certificate/security configuration, especially when using encrypted communications.
Common Use Cases
– Security patches and vulnerability remediation
– Fixing charging handshake issues or session stability problems
– Updating payment, authorization, or roaming-related logic
– Improving power control, such as load management behavior
– Enabling new diagnostics, logs, and remote troubleshooting features
– Compliance-related updates driven by new requirements or customer expectations
Key Benefits of OTA Firmware Updates
– Faster deployment of improvements across many chargers
– Reduced field service cost and lower operational disruption
– Better security posture with timely patching
– Higher uptime through bug fixes and stability enhancements
– Stronger ability to scale and maintain a multi-site charging network
Limitations to Consider
– Failed updates can cause downtime if rollback and validation are not robust
– Poor connectivity can lead to partial deployments and inconsistent fleet versions
– Requires strong key and certificate management to prevent malicious updates
– Large updates can stress bandwidth and extend maintenance windows
– Strict governance is needed to prevent untested releases from impacting customers
Related Glossary Terms
Secure Update Pipeline
Encrypted Communications
Charger Cybersecurity
OCPP 1.6 / 2.0.1
Charger Diagnostics
Uptime
Intrusion Detection
Cybersecurity Audits