Key features
OCPP 1.6 / 2.0.1 backend
Always-on channel to the CPO: sessions, authorization, power telemetry and remote firmware updates.
Payments & pricing
Payment gateways at the charger, contactless readers, and roaming across networks (OCPI / eMSP).
Live availability
Real-time status pushed to apps and mobility platforms: available, in use, out of service.
Remote maintenance
Remote diagnostics and session resets to cut down on truck rolls.
Dynamic load balancing
Smart charging and grid signal response to stay under contracted power.
Multi-carrier + private APN
Robust coverage in underground parkings. Optional static IP for VPN tunneling to the backend.
Use cases
Typical problems
- Chargers in mall basements with no single-operator coverage — the charger goes offline and users can't start an OCPP session.
- Truncated charging sessions because the charger loses backend connectivity mid-transaction — the CPO can't bill and the user complains.
- eMSP roaming that fails because OCPP between networks travels over the public Internet with variable latency.
- Residential AC chargers behind the customer's WiFi that changes password silently and leaves the charger misconfigured for weeks.
- DC fast chargers without static IP that the CPO can't diagnose remotely — every fault means a truck roll.
- Lack of coordination with the site's contracted power: the fast charger trips the main breaker when several chargers deliver at full simultaneously.
Recommended architecture
- 1
AC/DC charger with multi-operator SIM and OCPP 1.6J or 2.0.1 support
The multi-IMSI SIM picks the network with best coverage in the parking. OCPP 1.6J (minimum) or 2.0.1 (recommended) support to talk to any CPO backend without lock-in.
- 2
Private APN to the CPO's OCPP backend + static IP
The charger initiates a persistent WebSocket connection to the backend. Private APN avoids the public Internet; static IP lets the CPO reach the charger for remote diagnostics without an inverse tunnel.
- 3
Single backhaul per charging hub + internal Modbus
At stations with multiple chargers, a central industrial router links all chargers to the backend over a single SIM. Reduces cost and simplifies management of the shared power envelope.
- 4
Generous per-charger data plan (long sessions + telemetry)
An AC charger uses 50-200 MB/month; a DC fast charger with 1 Hz telemetry can hit 1-2 GB/month. Configure a generous plan + block alarm at 3x nominal to avoid bill surprises from reconnection loops.
Indicative data plan
| Device | Typical monthly traffic | Recommended plan |
|---|---|---|
| Residential AC charger 7-22 kW | 50-150 MB/month | 200 MB plan |
| Public AC charger (more sessions, frequent OCPP) | 100-300 MB/month | 500 MB plan |
| DC fast charger 50-150 kW (1 Hz telemetry) | 500 MB - 1 GB/month | 1 GB plan |
| DC ultra-fast 350 kW (with two-way video) | 1-3 GB/month | Pooled data |
Indicative figures. Frequent reconnections from network instability consume significantly more data — monitor the reconnect/uptime ratio.
When to use static IP
- The CPO's OCPP backend needs to initiate connections TO the charger for remote reconfiguration or diagnostics (Reset, ChangeConfiguration, GetDiagnostics).
- OCPI 2.2 eMSP roaming: the roaming hub identifies the charger by its source IP to resolve billing disputes.
- Regulatory audit (DGT, IDAE) for public charging points requires per-IP session traceability.
When to use private APN
- Corporate deployments where the CPO operates its own backend in VPC and doesn't want to expose OCPP endpoints to the Internet.
- PCI-DSS compliance for chargers with integrated contactless payment — mandatory payment traffic segmentation.
- Security compliance for charging points in critical infrastructure (hospitals, military facilities, public transport).
Compatible devices
Wallbox Commander / Pulsar Plus
Residential AC chargers 7-22 kW. OCPP 1.6J. WiFi connectivity + optional cellular module for sites without network.
Circontrol eVolve / eHome
AC and DC chargers manufactured in Spain. OCPP 1.6 / 2.0. 2FF SIM slot built into many models.
ABB Terra AC / Terra HP
AC and DC fast chargers up to 350 kW. ABB ChargerSync backend or generic OCPP. Remotely manageable cellular SIM.
ChargePoint Express series
DC chargers with proprietary backend or OCPP. Deployments mostly in North America and central Europe.
Schneider EVlink
AC chargers for residential and communities. OCPP 1.6 + EcoStruxure integration for multi-point management.
Industrial routers for charging hubs
Teltonika RUTX12, Cradlepoint or similar for stations with multiple chargers sharing backhaul. WAN failover and QoS.
Frequently asked questions
- Will the charger work in a basement with no 4G coverage?
- Yes, if it supports multi-band (LTE-M is excellent for basements) and the SIM is multi-operator. If coverage is very poor, install an industrial router with external antenna near the basement ceiling and connect the charger via local Ethernet. The SIM goes in the router, not the charger.
- Why not use the customer's WiFi for the residential charger?
- It works, but the customer eventually changes the WiFi password and the charger stays offline for weeks until the technician returns to reconfigure it. A dedicated SIM removes that dependency and drastically reduces support calls.
- How do I handle eMSP roaming across networks?
- Your OCPP backend needs to connect to the eMSP hub (Hubject, GIREVE, etc.) over OCPI 2.2. At SIM level, the important thing is that the charger has a static IP or stable egress — the eMSP hub correlates sessions by source IP to prevent fraud. Private APN optional but recommended.
- OCPP 1.6 or 2.0.1 for new deployments?
- 2.0.1 is the future: advanced smart charging, ISO 15118 (Plug & Charge), improved security, better error handling. But the ecosystem is still mostly on 1.6J. For 2026+ deployments, ask the manufacturer for 2.0.1 with 1.6J fallback if the backend only supports 1.6.
- What happens if the SIM runs out of data during an active session?
- The OCPP charger queues messages locally and sends them when connectivity returns. But if the plan is exhausted, the operator can block the SIM and the charger goes offline. Configure an alarm at 90% of the cap with auto-block at 100% to avoid mid-session cutoff.
Pre-deployment checklist
- 1Charger inventory: type (AC/DC), power, model, supported OCPP version, SIM format (2FF/3FF/eSIM).
- 2Coverage map by postal code and floor (basement vs street level) before choosing SIM.
- 3SIM-in-charger vs SIM-in-central-router decision for the charging station.
- 4Static IP decision (recommended for DC and all public chargers) vs dynamic IP.
- 5Public APN vs private APN to OCPP backend, considering PCI-DSS if integrated payment.
- 6Per-charger data plan with 3x headroom for reconnection loops and intensive telemetry.
- 7Coordination with the electrical contractor: site contracted power, ICP, and smart-charging configuration to stay within.
- 8OTA firmware update procedure and maintenance window.
- 9Integration with eMSP (Hubject, GIREVE, IberRoaming) if the charger is public and participates in roaming.
- 10Pilot of 5-10 chargers for 2 months monitoring uptime, completed vs truncated sessions, OCPP latency.
Need a printable version? See the pre-deployment guide.
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