Battery Profiling with the Otii Ace Pro by Qoitech

There’s something uniquely frustrating about batteries. For all their promise of portable power, they always seem to fall short, sometimes literally. You grab a fresh pack, slot one into your project, and... nothing. Or worse, it works perfectly for five minutes and then dies the moment you actually need it.

Unlike plug-in power supplies, which are as simple as plug-and-play, batteries are a whole different beast. They demand respect, special charging circuitry, safety checks, voltage regulation, chemistry compatibility—the list goes on. And even when you’ve ticked all the right boxes, the battery might still decide to misbehave.

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Now, imagine you’re designing a piece of kit for something as high-stakes as aviation. You’re not just fighting against discharge curves and dodgy connectors anymore, you’re fighting for absolute reliability in the sky. That’s exactly the kind of challenge the team behind PilotAware FX faced when trying to transition their electronic conspicuity device to run on battery power.

This is where things start to get interesting. Enter Qoitech’s Otii range, a series of advanced tools purpose-built to demystify battery behaviour, profile performance across different chemistries, and simulate real-world conditions with uncanny precision. For engineers dealing with power-critical projects, the Otii lineup is an essential addition to the tool bench.

Why Batteries Deserve More Respect

On the surface, a battery seems like a simple component. It stores energy, supplies power, and, when it’s flat, you replace or recharge it. But anyone who has spent more than five minutes working with portable electronics knows the truth...not all batteries are created equal.

Two AA cells from different brands can behave in wildly different ways. Even two units of the same make and model might offer inconsistent performance. The reason? A host of invisible variables, from manufacturing tolerances to chemical composition and even shelf life. What you don’t see on the label is what often makes the difference between reliable performance and random resets.

One of the most important and often overlooked factors is internal resistance. Every battery has it, and as current draw increases, so does the voltage drop caused by this resistance. That means under heavy load, your circuit might experience dips in voltage that you’d never catch on paper. Add in temperature sensitivity, and suddenly your once-stable setup is acting erratically in the field.

Now imagine dealing with all this in a product that flies. The PilotAware FX, for example, is a small but critical device used in light aircraft to report location and telemetry to nearby pilots. If a battery underperforms mid-flight due to temperature, discharge rate, or a manufacturing quirk that’s more than just an inconvenience. It could be a safety issue.

This is why accurate battery profiling is vital. Without it, you're designing in the dark, hoping the cells you spec’d will behave the way the datasheet says they should. In reality, without proper testing and simulation, you're gambling on performance you can't guarantee.

Meet the Swedish Powerhouse: The Otii Arc Pro and The Otti Ace Pro

The Otii Ace Pro by Qoitech: a compact, high-precision power analyzer and battery profiling tool designed for embedded and IoT developers.

The Otii Arc Pro: a versatile, USB-powered tool for battery emulation, power analysis, and energy profiling in low-power embedded systems.

Sweden has given the world a lot—Vikings, meatballs, flat-pack furniture, and some of the best winter tires you can buy. But nestled among the fjords and forests is something far more exciting for engineers: cutting-edge battery technology.

Qoitech, a Swedish company with a flair for precision engineering, has created a suite of tools that’s changing how developers test, profile, and optimize battery-powered devices. Their flagship line, the Otii range, combines power measurement, battery simulation, and real-time energy analysis in one neat package.

At the core of this lineup are two heavy-hitters: the Otii Ace Pro and the Otii Arc Pro. Both are designed with embedded developers in mind, offering fine-grained visibility into current draw, voltage behaviour, and battery response under load.

Whether you're developing low-power IoT sensors, aviation electronics, or portable consumer devices, the Otii range helps you answer the big question: how long will this thing actually run on a battery?

• Precision profiling & real-time simulation: Capture true battery behaviour with nanamp-level resolution and replay it digitally in software.
• USB-powered, compact form factor: Lab-grade measurement capabilities without taking over your entire workbench.
• Cross-platform compatibility: Seamlessly works with Windows, macOS, and Ubuntu via the intuitive Otii desktop app.

Whether you're chasing microamp sleep currents or validating complex energy budgets, these tools deliver the kind of insight that turns guesswork into certainty.

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Under the Hood: What the Otii Devices Actually Do

It’s one thing to talk about battery problems. It’s another to see exactly what’s going on inside a circuit when a battery is struggling. That’s where the real power of the Otii Ace Pro and Otii Arc Pro shines through. These devices don’t just analyze power—they let you live inside the power profile.

Real-Time Power Monitoring

Hook your device up to the Otii, fire up the software, and suddenly your current and voltage consumption are no longer guesswork. With up to 0.4 nA resolution, ±0.05% accuracy, and a 25V programmable output, you can watch in real time as your firmware turns peripherals on and off, enters sleep modes, and hits unexpected current spikes.

As shown in the script: “You can watch your device react to current draw in real time.” That’s not hyperbole. The software lets you zoom, scroll, and overlay UART logs while measuring power—so you know exactly what your device is doing and why the current spike happened.

Battery Profiling Magic

Here’s where things get serious. The Otii software, paired with the Battery Toolbox, allows you to create a digital twin of a battery. You start by fully charging a physical battery, then discharge it under a known load while the Otii records everything—voltage, current, resistance, and temperature-related behavior.

This profiling process gives you a curve that represents how that specific battery behaves throughout its lifecycle. It highlights internal resistance, shows how performance degrades under load, and captures quirks that you’ll never see on a datasheet. As shown in the test: “738mAh instead of 800mAh – still within spec, but good to know.”

• Step 1: Charge the battery with precision control
• Step 2: Discharge it under a scripted load
• Step 3: Capture high-resolution power data
• Step 4: Extract internal resistance and behavior curves

Use this data with the Battery Life Estimator to simulate real-world duty cycles, active/sleep ratios, and environmental conditions. No more guesswork—just accurate, project-specific power insights.

Battery Emulation That Feels Like Science Fiction

Now comes the coolest part: real-time battery emulation. Once you’ve profiled a battery, the Otii software can simulate its exact behavior—at any charge level. Want to see what happens at 10% in sub-zero conditions? Done. Want to replay a full battery cycle across a week of IoT data? Go for it.

Need a custom battery bank? You can virtually bank batteries in series and parallel, scaling voltage and capacity without touching a soldering iron. Then drag a slider to simulate various levels of depletion and watch your firmware respond.

Advanced Capabilities at a Glance:

• Adjustable sample rates up to 50 ksps
• UART synchronization with power traces
• True 4-wire measurement for pinpoint accuracy
• Scripted automation and data export (CSV, ZIP)

Whether you're tuning ultra-low power sleep currents or validating flight-critical systems, the Otii range doesn't just observe—it empowers.

Pro Tips for Engineers Using the Otii Ecosystem

While the Otii Ace Pro and Arc Pro are standout tools for battery profiling, their true strength lies in how seamlessly they fit into a modern engineering workflow. Whether you're building an ultra-low-power sensor node or validating edge-case behavior in embedded firmware, the Otii ecosystem provides a robust, flexible platform for data-driven development.

Top Use Cases to Supercharge Your Workflow

• Low-power IoT debugging: Visualize current consumption down to the nanoamp level. Identify sleep mode leaks, transient spikes, or unexpected wake events with clarity that traditional tools can't offer.
• Regression testing with power baselines: Ensure that firmware updates don’t silently degrade power efficiency. Compare power traces between software revisions and catch performance drifts before they reach production.
• Profiling supercapacitors and lithium titanate cells: Understand the unique charge/discharge behaviors of emerging storage technologies. Validate how they handle surge loads, recover from brownouts, and maintain stability over time.

Software Flexibility That Engineers Actually Need

The Otii ecosystem doesn’t lock you into a proprietary setup. Instead, it’s designed to integrate into your existing toolchain and scale with your projects.

• Platform-agnostic operation: Use the Otii desktop app on Windows, macOS, or Ubuntu with full feature parity.
• Scriptable automation: Write custom workflows and automated tests in Python, C#, MATLAB, or Java using the built-in TCP JSON API. Perfect for continuous integration environments and automated hardware validation.
• Collaborative data handling: Export measurements to CSV for deep analysis, or save entire sessions as shareable project archives (.zip) for team reviews and repeatable testing.

Otii tools are more than just bench instruments—they’re insight engines for the modern embedded developer. With real-time visibility, scriptable automation, and precision analytics all in one package, they transform the way you design, test, and validate your power-critical projects.

Where to Get Your Hands on One

If you’re serious about understanding the true behavior of your battery-powered devices—or just want to stop guessing why things keep resetting—then the Otii range deserves a spot on your bench. Whether you’re deep into power optimization or just starting to explore energy profiling, both the Ace Pro and Arc Pro offer the insight and flexibility modern engineers need.

The Otii Ace Pro is the go-to tool for high-voltage applications and advanced battery emulation, while the Otii Arc Pro offers outstanding value for developers focused on compact embedded systems and efficient IoT hardware.

Explore the range and level up your power debugging workflow:

• Shop the Otii Ace Pro – The Ultimate Power Analyzer
• Check out the Otii Arc Pro – Affordable Battery Profiling