What is a charging station management system (CSMS)?

What a CSMS does

• Monitoring

  Which chargers are online, which connectors are free, busy or faulted, and what the charger reports.

• Authorisation

  Decides whether a driver may start: app user, guest or corporate account.

• Tariffs

  Applies the price per kWh, session fees and idle fees, by station or by time.

• Sessions and meter data

  Records start, stop and meter readings, the basis of every invoice.

• Billing and payments

  Takes payments, keeps balances, issues receipts and handles refunds.

• Remote control and reports

  Reset, unlock, change settings, send charging profiles; reports on energy, revenue and faults.

CPO and eMSP

A charge point operator owns or runs the chargers and the CSMS. An e-mobility service provider gives drivers the app, the account and the payment. One company often does both, as EV Armenia does for its own network. When they are separate companies, a protocol called OCPI lets them exchange authentication, authorisation, billing and sessions, either directly or through a hub. This is how roaming works. See OCPP explained.

A charging session from the CSMS’s side

Whatever the product, the CSMS follows the same story every time a car is plugged in. The message names below are OCPP 1.6 terms; version 2.0.1 groups the transaction messages into one called TransactionEvent.

1. The charger connects. It opens a WebSocket to the CSMS and sends BootNotification. The CSMS accepts it and sets how often the charger must send a heartbeat.
2. Connectors report their state. Each connector announces whether it is available, preparing, charging or faulted, so the map shows the truth.
3. The driver asks to start. The app calls the CSMS, which checks the account or the guest payment and, if everything is in order, tells the charger to start.
4. The charger starts a transaction. It sends the first meter reading, and the CSMS opens a session.
5. Meter values arrive. The charger reports energy while the car charges. The CSMS turns kilowatt-hours into money with the tariff.
6. The session ends. The CSMS records the final reading, takes or settles the payment, and shows the driver a receipt.

Every step has failure modes: a dropped connection, a lost message, a payment that never confirms. A good CSMS is mostly defined by how it behaves when something goes wrong, not by the happy path.

Where a CSMS sits

Chargers talk to the CSMS. The CSMS talks to payment providers, to the driver app and to the operator’s admin panel. The chargers never talk to the payment provider directly, which is why billing logic lives in the CSMS. If the CSMS is down, chargers can usually finish a session they have already started, but new sessions and payments wait until it returns.

What to look for in a CSMS

• OCPP versions your chargers use: 1.6J, 2.0.1, 2.1.
• Reliable meter data: no lost readings after a restart.
• Local payments: in Armenia, Idram, ArCa cards and Fastshift; see payments.
• A driver app in the languages of your drivers, or the ability to brand one.
• Roles and audit: who changed which tariff.
• Hosting options: hosted by the vendor or installed on your server.
• Honest limits: what the product does not do yet.

Our OCPP CSMS covers these points, and the platform overview lists what is not built yet, such as automatic load management.

Build or buy

Writing your own OCPP server is possible, but the work that follows the protocol (payments, wallet, refunds, support tools, apps) is much larger than the protocol itself. See the comparison in build or buy a CSMS.