Battery Life Optimization in IoT Devices: Engineering Techniques That Make It Happen

Why Battery Optimization Is Critical in the IoT Era

IoT devices — from asset trackers and smart meters to wearables and industrial sensors — are often deployed in locations where changing batteries is difficult or costly. In some applications, the expected lifetime is 5 to 10 years on a single cell.

That makes battery life optimization not a nice-to-have, but a design requirement.

In this article, we share how Promwad engineers approach power-sensitive hardware design, what tradeoffs we make, and which techniques help extend battery life without compromising device performance.

Step 1: Choose the Right Battery for the Job

Battery selection defines the current and voltage envelope for your system.

Step 2: Hardware Design for Low Power

Component Selection:

• Use ultra-low-power MCUs with multiple sleep modes (e.g., STM32L, nRF52, Ambiq Apollo)
• Choose low Iq regulators (<1 µA quiescent current)
• Favor components with hardware shutdown pins over software-only idle
• Avoid excessive sensor polling and noisy ADCs

Circuit Techniques:

• Use load switches or FETs to disable unused blocks
• Buffer and batch sensor data to avoid frequent radio transmissions
• Route analog signals efficiently to reduce op-amp and bias current

Step 3: Firmware Strategies for Power Savings

Sleep Mode Utilization:

• Design state machines to spend most time in STOP or STANDBY modes
• Use RTC or GPIO wakeups, not polling loops
• Offload tasks to low-power peripherals (e.g., timers for PWM or capture)

Communication Management:

• Use BLE advertising instead of connections when possible
• Schedule LoRa or NB-IoT transmissions to avoid retries
• Disable Wi-Fi radios during inactivity

Firmware Tips:

• Calibrate oscillators once and store result
• Avoid unnecessary flash/EEPROM writes
• Profile ISR duration and avoid wakeup storms

Step 4: Power Profiling and Measurement

You can’t optimize what you don’t measure. Tools we use:

Power profiling helps reveal hidden drains — like GPIO pull-ups or active pull-downs.

Real-World Use Case: Asset Tracker

• Challenge: 5-year life on 3.6V lithium battery
• Approach: STM32L MCU + Quectel NB-IoT modem
• Techniques: Sleep most of the time, wake on movement
• Result: Avg. current reduced to <15 µA idle, <100 mA TX burst

Device passed thermal chamber cycling and outdoor field deployment.

Other Techniques Worth Exploring

• Use energy harvesting (solar, piezo) where feasible
• Adopt event-driven architecture vs polling logic
• Implement power budgeting early — not just power measurement later
• Schedule firmware updates or sensor checks in off-peak power windows
• Use RTOS power management features or go bare-metal for full control

Final Thoughts

Battery life optimization is a multi-layered challenge that spans component selection, power electronics, firmware timing, and system-level tradeoffs. It’s not a single trick — but a mindset.

At Promwad, we help clients design IoT products that meet years-long battery life goals — without compromising performance or user experience.

Let’s make your next device smarter — and last longer.