Question 1

Does an EV charger still work when it goes offline?

Accepted Answer

It can, if it was configured to. With LocalAuthorizeOffline enabled and a current local authorisation list or authorisation cache, an OCPP charger will authorise known identifiers, meter the session locally and queue the transaction messages for replay on reconnect. Without those settings it simply refuses to start. What it cannot do while offline is accept a remote reset, report a fault, or push a session into billing in real time.

Question 2

How much data does an EV charger use on an M2M SIM card?

Accepted Answer

A busy charger reporting MeterValues every 60 seconds typically uses 15–25 MB a month of OCPP telemetry, of which heartbeats are only 3–4 MB. Fifteen-second metering roughly quadruples the meter-value share. Firmware is the spike: a single 5–20 MB image can equal a month of normal traffic, so size the plan at around 100 MB per charger per month rather than to the telemetry average.

Question 3

Is OCPP 2.0.1 better than 1.6J for offline operation?

Accepted Answer

Yes, materially. In OCPP 1.6 the central system generates the transaction ID, so an offline session must carry a temporary ID and its queued messages must be replayed in order. OCPP 2.0.1 replaces the separate transaction messages with one TransactionEvent message, moves ID generation to the charging station, adds a sequence number so the CSMS can detect gaps, and lifts the chronological-order requirement — which makes an interrupted session far easier to reconstruct and audit.

Question 4

Can we just use the site host's Wi-Fi for our chargers?

Accepted Answer

For revenue-earning public chargers, no. Host Wi-Fi fails on captive portals, scheduled password rotations, guest-network session timeouts and VLAN changes nobody tells the CPO about — and the CPO still carries the uptime obligation on a network it does not control. Use a cellular M2M SIM card as the primary path and treat host connectivity as a documented backup written into the site agreement.

Question 5

What are the M2M SIM rules for EV chargers in India?

Accepted Answer

M2M connections are issued in bulk in the name of the organisation providing the M2M service, with restrictive features and separate KYC, under DoT's instructions of 16 May 2018, and India uses a dedicated 13-digit M2M numbering series. DoT's M2MSP registration guidelines of 8 February 2022 apply to entities providing M2M services over licensed telecom resources. For imported hardware, TRAI's March 2024 eSIM recommendations propose a six-month limit before a foreign profile must be replaced with an Indian operator's profile — verify the current enforceable position with counsel.

EV Charger Connectivity: M2M SIM Card Choices And What Takes A Site Offline

RFID Card For EV Charging: The Authorisation Layer Operators Must Get Right

EV Charging Station Design: Bay Layout, Connector Mix And Canopy Decisions

Multi-Vendor EV Charger Management: Running A Mixed-OEM Fleet On One Platform

EV Charger Remote Monitoring: Cutting Downtime Before Drivers Notice

cpo operations

EV Charger Connectivity: M2M SIM Card Choices And What Takes A Site Offline

RFID Card For EV Charging: The Authorisation Layer Operators Must Get Right

EV Charging Station Design: Bay Layout, Connector Mix And Canopy Decisions

Multi-Vendor EV Charger Management: Running A Mixed-OEM Fleet On One Platform

EV Charger Remote Monitoring: Cutting Downtime Before Drivers Notice