An LTE modem is a cellular communication module that enables an EV charger (or a site gateway) to connect to the internet over 4G/LTE mobile networks. In EV charging, an LTE modem provides backhaul connectivity for charger management, monitoring, firmware updates, and transaction processing—especially when wired Ethernet is unavailable or impractical.
What Is an LTE Modem?
An LTE modem is a device or integrated module that:
– Connects to a mobile network using a SIM or eSIM
– Converts cellular radio connectivity into IP data connectivity for the charger
– Supports networking features such as APN configuration, VPN tunnels, and firewall rules (depending on setup)
LTE modems may be built into the charger or installed as an external router/gateway.
Why LTE Modems Matter in EV Charging Infrastructure
Reliable connectivity is essential for operating networked EV charging:
– Enables communication with a Charge Point Management System (CPMS) via OCPP
– Supports user authorization (RFID/app), session control, and pricing updates
– Sends diagnostics, alarms, and uptime monitoring data
– Enables remote configuration and OTA firmware updates
– Simplifies deployment where trenching Ethernet is costly or impossible
For many public and distributed installations, LTE is the fastest way to bring chargers online.
How LTE Connectivity Is Used by EV Chargers
In typical deployments, the LTE modem supports:
– Persistent or periodic communication to the backend (OCPP heartbeat, status updates)
– Transaction data exchange (start/stop, meter values, session summaries)
– Remote commands (reset, unlock connector, set charging profiles)
– Telemetry uploads and event notifications
If the connection drops, chargers may use offline modes (local authorization lists, cached tariffs) depending on configuration.
Key LTE Modem Features Relevant to EV Charging
Important technical features for charging infrastructure include:
– SIM/eSIM support and remote provisioning
– Antenna options (internal vs external; high-gain antennas for basements)
– Network band support aligned with local operators
– Fallback modes (3G/2G where still available, or multi-network roaming SIMs)
– Security capabilities (VPN, TLS support, private APN options)
– Remote management and monitoring for the modem/router itself
Practical Considerations for Installers and Operators
LTE deployments should account for real-world site conditions:
– Signal strength in underground parking, steel structures, or enclosed cabinets
– Antenna placement and cable routing to reduce attenuation
– Data plans sized for expected traffic (meter values frequency, logs, firmware updates)
– Firewall and port rules required by the CPMS and OCPP security configuration
– Resilience strategy (dual SIM, roaming SIM, or Ethernet + LTE backup where needed)
Connectivity planning is often a major factor in achieving consistent uptime.
LTE vs Ethernet for EV Chargers
Typical differences:
– Ethernet: highest stability and lowest ongoing data cost; requires cabling and network access
– LTE: fastest to deploy and flexible for remote sites; depends on coverage and SIM management
Many operators use Ethernet when available and LTE as primary or backup connectivity for reliability.
Related Glossary Terms
Cellular connectivity
SIM / eSIM
OCPP
Charge Point Management System (CPMS)
Charger uptime
OTA firmware updates
Gateway
Network redundancy
Offline authorization