Building Battery-Efficient IoT Devices for Real-World Applications

By Srihari Maddula, Director – Product Design, Eurth Tech

In the world of connected devices, there’s a quiet truth that engineers eventually learn the hard way: a brilliant IoT product is only as good as its battery life.

Whether it’s a wearable on a wrist, a soil sensor buried in farmland, or a GPS tracker mounted on a container, power efficiency isn’t just a design consideration—it’s a business imperative. Miss the mark, and you’ll face field failures, mounting service costs, and loss of customer trust.

At Eurth Tech, we’ve designed and deployed battery-powered IoT systems across domains—and here’s what we’ve learned about squeezing the most out of every microamp.

The Real Power Challenge: Theory vs. Field

On paper, power estimates look promising. A 2400mAh battery, 10µA sleep current, radio bursts every 30 minutes—sounds like two years of life, right?

But when we deployed a field tracker designed for a 12-month cycle, devices began dying in less than five months.

Postmortem diagnostics revealed:

• High self-discharge under extreme temperatures

• Inefficient LDO regulator wasting over half the power

• Wake-ups triggered by trivial motion

That’s when we stopped thinking in component-level datasheets, and started thinking in system-level energy budgets.

System-Level Power Budgeting: Think Holistically

The first rule of power design is this: everything consumes power—even when it’s “off.”

We began mapping out every subsystem’s energy profile across its states: active, sleep, and transition. Here’s how that framework looks:

Subsystem	Examples	Design Considerations
MCU	Cortex-M series, RISC-V, ESP32	Sleep/active current, wake-up time, clock scaling
Sensors	IMU, temperature, soil moisture	Sampling rate, warm-up time, interrupt-based triggering
Wireless Module	BLE, LoRa, Wi-Fi	TX/RX current, duty cycle, retries, handshake overhead
PMIC & Regulators	LDO, Buck, Buck-Boost	Quiescent current, efficiency under variable load
Leakage Paths	GPIO pull-ups, diodes, LEDs	Peripheral shutdown, pin states, reverse current protection

Pro Tip: Use tools like Joulescope or Nordic’s Power Profiler Kit to visualize consumption over time.

Voltage Regulation: The Silent Killer

Voltage mismatches and improper regulator choices quietly drain your battery. We’ve seen devices lose 40–50% of usable energy purely due to inefficient conversion.

Regulator Type	Ideal For	Efficiency Range
LDO	Very low current, small voltage delta	50–70%
Buck Converter	High current, large step-down	85–95%
Buck-Boost	Battery voltage swings across thresholds	75–90%

Example: Supplying 1.8V @ 20mA from a 3.6V battery using an LDO yields <60% efficiency. Replacing it with a buck increased run-time by 2× in our agriculture sensors.

Also important: quiescent current. Some regulators draw >10µA in “sleep,” silently bleeding energy. Always check the datasheet beyond load efficiency curves.

Communication Optimization: Less is More

Wireless radios are often the largest energy consumers in IoT devices. Optimizing communication is more than choosing the right protocol—it’s about how often and how much you transmit.

Protocol	Best Use Case	Power Characteristics
Wi-Fi	High-bandwidth bursts	High current, short-duration
BLE	Proximity, wearables	Very low power, short-range
LoRa / Sub-GHz	Remote sensing, long-range	Long TX time, low average current
NB-IoT / LTE-M	Asset tracking, urban IoT	Medium power, useful for infrequent sync

What made the biggest difference for us was adaptive logic.

Case Study:An irrigation controller was originally configured to report soil status every 5 minutes. After adding edge-based decision-making, it only transmitted when values crossed thresholds. This reduced TX cycles by 80% and tripled battery life.

Firmware as the Frontline of Efficiency

Your firmware holds the keys to runtime success—or failure. Even a 5µA sleep current chip won’t help if the code wakes it up every second.

Here’s a checklist we use in every EurthTech firmware stack:

• Deep Sleep & Standby: Use the lowest possible power states between tasks.

• Interrupt-Driven Wakeups: Sensors, RTCs, and motion triggers instead of polling.

• Peripheral Shutdown: Explicitly disable unused modules like UART, ADC, or I²C.

• Duty Cycling: Schedule communication and sensing with generous gaps.

• Dynamic Clocking: Reduce clock speed during low-load operation.

We also recommend adding firmware instrumentation to log:

• Wake count

• Average active duration

• Sleep ratio over 24 hours

This telemetry helps bridge lab measurements and field behavior.

Battery Chemistry: Not All Cells Are Equal

Choosing a battery isn’t just about capacity. Chemistry, voltage curves, temperature response, and self-discharge are just as critical.

Chemistry	Best Use Case	Notes
Li-ion / Li-Po	Rechargeable wearables	High energy density, limited cold tolerance
Li-SOCl₂	Industrial long-life sensors	Very low self-discharge, but non-rechargeable
NiMH	Cost-sensitive, cyclic usage	Good for consumer-grade sensors, moderate energy density

Other key design questions:

• Can the battery handle radio burst peak currents (100–300mA)?

• Will the chemistry survive -20°C deployments?

• Does it degrade predictably enough for battery life estimation?

Environmental Testing: Beyond the Bench

Your lab numbers may look excellent—but nature doesn’t care. Field validation is the ultimate test.

What we test before pilot deployment:

• Temperature Variation: Check quiescent current at -20°C and +60°C

• Ingress and Corrosion: Watch for water seepage and PCB oxidation

• Load Simulation: Emulate real-world sensor usage patterns and sleep cycles

We log consumption every 15 minutes in firmware and cross-check with oscilloscope traces and profiler readings to correlate code events with power spikes.

Designing for Predictability and Serviceability

Even the best systems will one day run out of charge. Build for that day:

• Low Battery Alerts: Trigger cloud alarms when voltage drops below threshold

• Replaceability or Rechargeability: Enable quick swaps or USB charging

• Remote Tuning: Allow OTA configuration to tweak sampling or sync intervals

• OTA Firmware Support: Push efficiency upgrades without visiting the site

We’ve seen 20–30% gains in battery life just from firmware updates that optimize timing and reduce unnecessary peripheral usage.

Final Thoughts: Every Microamp Matters

Building truly power-efficient IoT systems is an art backed by science.

It requires understanding:

• How voltage regulators behave across loads

• How wireless modules consume in retry loops

• How your firmware wakes up when nobody’s looking

At EurthTech, we treat every product like a system, not a parts list. When every component, line of code, and packet counts—we help you build devices that last not just months, but years in the field

💡 Need to build a zero-maintenance IoT device? 📞 Talk to our design team and run a Power Profiling Session before your next deployment.