IONIQ 5 OBD2 Monitor

One tap to every system

After connecting, the dashboard is your home base. Each card opens a themed screen grouped around one part of the car, with a short summary of what it contains so you can jump straight to what you need.

Throughout the app, almost every value is tappable: tap a reading and a pop-up explains in plain language what it means and what a healthy range looks like, so you are never left guessing what a number or dial is telling you.

Battery Status

The Battery Status screen gives you the whole high-voltage battery at a glance. The "fuel tank" graphic at the top fills like a petrol gauge: the green level is the energy available right now (Remaining Energy in kWh) against the battery's total Usable Capacity. Below it you get SOC (BMS), the true state of charge the battery management system works with, alongside SOC (Display), the slightly buffered figure shown on the car's own cluster.

Usable Capacity: measured, not looked up

This app measures your battery capacity. The car never reports its capacity directly, but it does report, continuously, how much energy is left and what the true state of charge is. Watched over time, those two numbers contain the answer. Every percent of charge you use or add is a small experiment, and the app quietly keeps score.

You can watch it grow up. On day one it shows a single-reading estimate, corrected for the quirk that the car's "remaining energy" reaches zero at roughly 7 % real charge rather than at 0 %. As you drive and charge, the observed span widens and the label tells you exactly how much evidence is behind the number: first (estimate), then the actual range it has measured across, such as (18–84 %), and finally (verified) once it has seen a span of 60 % or more. Nothing is hidden: the app tells you how confident it is.

The calibration is tied to your car's VIN, so plugging into a different IONIQ 5 starts a fresh measurement rather than quietly reporting the wrong car's pack. Implausible results are rejected rather than displayed. And the whole thing needs no input from you: no model selection, no full charge-discharge cycle to "learn" the battery. Just use the car.

The Power dial

The Power Status bar is a live, two-ended dial. The pointer sits in the middle at rest and swings left into the green when energy is flowing into the battery (regenerative braking or charging) and right into the red when power is being drawn out (accelerating). The ends of the scale match the battery's current limits, so you can instantly see how hard the pack is working relative to what it will allow.

Battery Temperatures

Temperature drives charging speed, range and battery longevity. The top chart shows one bar per battery module, and each bar is colour-banded by temperature: deep blue below 0°, cyan 0–14°, green 15–35° (the ideal window), amber 36–45°, orange 46–55° and deep red above 55°. One glance tells you whether the whole pack is in its happy zone.

The Spread dial

Below the modules, the Spread dial shows the gap between the warmest and coldest module on a 0–15°C scale that runs green → red.

Diagnostics

The Diagnostics screen turns the most important health figures into a stack of colour-graded dials, one card each, so you can judge the pack's condition in seconds. The cards are laid out below in the order they appear on the screen. They are not equally important, though: the single best predictor of trouble is Cell Imbalance, which has its own card further down.

State of Health

State of Health (50 to 100%) is reported directly by the car and tells you how much of the original capacity the pack has kept, so fuller and greener is better. Useful to know, but read it for what it is: a slow measure of range, not a warning light. It drifts down a few percent in the first year or two and then a percent or so a year. It will not spot a single cell about to fail. That is the job of Cell Imbalance, below.

Battery Round-Trip Efficiency

Round-Trip Efficiency (50 to 100%) is how much energy you get back out versus what you put in. Higher and greener is better. A pack that is quietly getting less efficient over time is doing more of its work as heat, which is a gentle sign of ageing. Beneath this card the screen lists the lifetime totals the BMS has counted since the car was built: charged and discharged kWh and Ah.

Cell Imbalance: the one to watch

If you read only one dial on this screen, read this one. Cell Imbalance (0 to 100 mV) is the gap between the highest and lowest cell voltage in the pack, and it is the best early warning of a weak or failing cell. It matters more than State of Health for reliability: a pack fails because one cell goes bad, and that shows up here long before it shows up anywhere else. Low and green is healthy; a long red bar means the cells are drifting apart. The max and min cell voltages behind the figure are listed on the card.

High-Voltage Bus

The High-Voltage Bus dial shows the DC-link gap: the battery pack voltage minus the inverter's DC-link capacitor voltage while the main contactor is closed, on a 0 to 5 V scale. With the bus live the capacitor sits right across the pack, so this gap is essentially the small voltage drop across the contactor and busbars, and lower and greener is better. A reading near 0 V (green) means a healthy, well-connected bus; a growing gap (amber → red) points to extra resistance in the high-voltage path. When the bus is not live (main contactor open, car asleep) the dial simply shows a dash. Pack voltage, capacitor voltage and link status are listed beside it.

Insulation Resistance

The Insulation Resistance dial tracks the electrical isolation between the high-voltage system and the car body, and here higher is better (a healthy pack reads well above 1000 kΩ). This is a safety figure: if it falls far enough the car itself will warn you and can refuse to drive, because it means current could leak to the chassis.

Isolation & Safety

The last card is a row of fault flags that light up only if the BMS has ever recorded a problem: an over- or under-voltage, over- or under-temperature, over-current, short-circuit or isolation fault. On a healthy pack they all stay clear. It is the first place to look if the car has thrown a battery warning.

Vehicle details

The Vehicle details screen gathers the general car data that does not belong to a single system. Live motion data, speed plus rear and front motor RPM, lets you watch the drive unit work in real time, including how the front and rear motors share the job during all-wheel-drive driving.

Lifetime figures include the odometer straight from the cluster and the BMS operating hours, the total time the battery system has been awake since the car was built.

Climate: the air-conditioning, honestly

The climate card shows Indoor Temp (the cabin sensor) and Evaporator Temp, which is the single best answer to "is the A/C actually cooling?", since it drops sharply the moment the compressor engages. Then Vent Air Temp, the air as it actually leaves the vents, and Refrigerant Pressure. That last one is the low-pressure side, so it reads lower while the compressor runs and sits high and steady when the system is idle: low means cooling.

Hypermiling

Hypermiling is a live efficiency coach that helps you squeeze more range out of every charge. The big number is your current efficiency in km/kWh, and the tall bar graph beside it is the dial: the bars fill upward and turn greener the more efficiently you drive, and drop down into amber and red when you use more energy.

Make it yours

Tap the ⋮ menu on the dashboard and choose Preferences. Your choices are remembered between sessions and apply everywhere in the app at once.

Pick the units you actually think in: tyre pressure in PSI or bar, temperature in °C or °F, and distance in kilometres or miles.

Keep the screen awake

Set the Screen timeout to suit how you use the app. Leave it on Use phone setting to follow Android's normal display timeout, hold the display on for 5, 10 or 15 minutes of inactivity, or choose Never to keep the screen on the whole time the app is open — ideal when the phone sits on a dash mount and you are watching a charge or a live gauge. It applies to this app only, so it never changes how the rest of your phone behaves.

Auto-connect to your adapter

The one setting worth explaining. Normally, starting the app means scanning for Bluetooth devices and tapping your dongle in the list, every single time, even though the answer never changes.

It stays safe when things are not routine. If your usual adapter isn't found (a different car, a dongle left at home, a flat battery in the plug), the app simply shows the normal device list so you can pick another one. It only ever auto-connects to an adapter that has already worked for you, never to something new it has just discovered.

The setting is off by default, so nothing changes unless you ask for it.