EV Charging Platform Testing Case Study

Case study: EV charging & IoT

Every kilowatt counted. Every rupee reconciled.

How Optimworks helps India’s EV charging networks ship reliable Charge Management Systems (CMS), by testing chargers, availability, charging levels and payments end to end, with manual and automation testing working together.

The journey we test: one charging session, five hand-offs

A defect at any hop becomes a stuck charger, a wrong bill or an unhappy driver.

1
Charger + IoT
AC / DC, meter, connector

2
OCPP gateway
Status, heartbeat, meter values

3
CMS + driver app
Availability, start / stop

4
Payments
UPI, wallet, cards, refunds

5
Invoice + ledger
kWh to rupees to GST

1,500+
test cases across CMS, app and IoT flows

70%
of regression automated

3x
faster release validation

0
billing mismatches escaped to production

The challenge

India’s EV market is growing fast, and charging operators are scaling networks across cities and highways. Their software has to work with many charger brands, patchy networks and real money changing hands, all at once.

What made it hard

  • Multiple charger makes and firmware versions speaking OCPP differently
  • Chargers dropping offline mid-session on weak connectivity
  • Availability shown in the app not matching the real charger state
  • Billing by kWh, time and idle fee, with taxes and refunds
  • Frequent releases with little time for full regression

What was at stake

  • Drivers reaching a charger the app called “available” but was faulted
  • Over- or under-billing that erodes trust and revenue
  • Sessions that never stop, or stop with no payment captured
  • Support load and lost repeat usage

How Optimworks tested it

Two complementary practices: experienced testers for judgement and edge cases, and automation for speed and repeatability.

Manual testing

  • Charging levels:
    AC slow and fast, DC fast (CCS2, CHAdeMO, Type 2), power ramp and cut-off
  • Real-charger field checks:
    plug-in, RFID, QR start, emergency stop, connector faults
  • Availability states:
    available, preparing, charging, finishing, faulted, unavailable
  • Money scenarios:
    partial charge, wallet top-up, failed UPI, duplicate callbacks, refunds
  • Exploratory and usability
    on driver and operator apps

Automation testing

  • OCPP simulators
    to replay charger messages and inject faults at scale
  • API automation
    for sessions, tariffs, wallets and invoices
  • UI automation
    for CMS dashboards and mobile apps
  • Regression in CI
    on every build, with clear pass / fail reports
  • Load and soak tests
    for many chargers reporting at once

Our approach

1

Understand the domain

Map charger types, OCPP versions, tariffs and payment rules.

2

Build the risk map

Rank flows by impact: availability, session control, billing.

3

Design and execute

Manual test design first, then automate the stable, repeatable flows.

4

Reconcile the money

Match kWh from the meter to the session, invoice and ledger.

5

Report and improve

Daily reports, defect trends and release sign-off.

What the client gained

Trust in availability

Charger status in the app matched the field, so drivers stopped arriving at faulted chargers.

Accurate billing

End-to-end reconciliation caught rounding, tax and refund defects before launch.

Faster, safer releases

Automated regression cut validation from days to hours on every build.

Scale-ready platform

Load tests showed how the CMS behaves as the charger network grows.

Tools and standards

OCPP 1.6J / 2.0.1
OCPI roaming
Bharat AC / DC
CCS2
Selenium
Playwright
Appium
REST Assured
Postman
JMeter / k6
CI/CD pipelines
Charger simulators

Building or scaling an EV charging platform?

Talk to the Optimworks QA team. We will review your CMS, IoT and payment flows and show you where the risks are.

Client details are kept confidential.

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