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Project 03 / 04 — Completed Nov 2021

EV Black Box

Built for Flip The Fleet — NZ's largest EV research initiative

A custom-designed hardware IoT product: a compact install-and-forget OBD-II device that reads EV battery health, consumption, and driving data in real time, transmitting via cellular to a personal cloud dashboard. Designed, manufactured, and sold by Exact IOT — approximately 50 devices were deployed across New Zealand in Nissan Leafs and e-NV200s, collecting over 9 million telemetry records.

~50 Devices Deployed
9M Telemetry Records
30GB+ Data Collected
EV Black Box v1.6 — custom-designed PCB with SIM card slot, micro-USB, and mounting standoffs
The Challenge

Understanding EV battery degradation at scale

Flip The Fleet needed real-world data from electric vehicles across New Zealand to study battery degradation patterns, driving efficiency, and the long-term health of second-hand EVs. The data available from apps like LeafSpy was manual — owners had to remember to export logs, and the data was inconsistent.

They needed an automated, always-on device that ordinary EV owners could install in minutes with no specialist tools. Something that would self-power from the vehicle, never interfere with onboard electronics, and silently stream telemetry to a researcher-accessible dashboard.

Early EV Black Box prototype — Arduino-based CAN Bus Shield with serial connector and USB adapter
The Solution

From breadboard to manufactured product

Exact IOT designed the EV Black Box from scratch — starting with an Arduino-based prototype on a CAN Bus Shield, progressing through integrated prototypes with cellular modems, and arriving at a professionally manufactured custom PCB (v1.6) with SIM card slot, voltage regulation, and proper mounting.

The device plugs into the OBD-II port, reads battery cell voltages, state of health, energy consumption, and speed via CAN bus. Data transmits over cellular to an Azure-hosted dashboard where each owner gets their own real-time view. Installation takes minutes, and the device operates in read-only mode — it never writes to the vehicle's systems.

Integrated EV Black Box prototype — stacked board assembly with cellular module and GPS antenna
Development Journey

From prototype to production

EV Black Box v1.6 — final production PCB closeup showing SIM slot, micro-USB, voltage regulator
Early prototype — Arduino CAN Bus Shield with serial connector
Integrated prototype with cellular modem and GPS antenna
Technical Details

Under the hood

The EV Black Box was a purpose-built embedded device combining automotive diagnostics with cellular IoT. It communicated via CAN bus to read proprietary Nissan EV battery management data — 283 data points per record including 96 individual cell voltages, pack temperatures, motor stats, and driving telemetry. Data transmitted over cellular to Azure-hosted cloud infrastructure. Across the fleet, the system accumulated over 1.2 billion individual data points. Each device retailed at $300 + GST with a $30/month service fee covering connectivity, database hosting, and dashboard access.

OBD-II CAN Bus Cellular IoT LTE-M Azure C# .NET MQTT SQL Server Embedded C
ev-blackbox.specs
Hardware Custom PCB + Enclosure
Interface OBD-II (CAN Bus)
Connectivity LTE-M Cellular
Power Vehicle OBD Port (12V)
Data Points 283 per record
Fleet Data 9M records / 30GB+
Devices ~50 across NZ
Cloud Platform Azure (App Service + SQL)
Dashboard ASP.NET MVC
Vehicles Supported Leaf, e-NV200
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hardware product?

The EV Black Box demonstrated our end-to-end capability: from initial prototype to manufactured product with cloud dashboard. If you have a similar challenge, we'd like to hear about it.

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