What is it?

This is an ultra low-power power supply and battery charging module designed for ESP32, Arduino, and other microcontroller-based devices. It provides a stable 3.3V output and integrates a lithium-ion/lithium-polymer battery charger (up to 500 mA) with a high-efficiency buck-boost converter.

Why did I make it?

Many DIY and IoT projects run on batteries, but typical power solutions are inefficient and waste energy in standby mode. I needed a compact, energy-efficient module for my own projects — one that could deliver stable 3.3V and extend battery life without complex configuration. So I designed this module for developers who care about long-term performance and reliability.

What makes it special?

• Ultra-low quiescent current: only ~17 μA in standby
• Smart power path management: switch seamlessly between USB and battery
• High-efficiency buck-boost converter based on TPS63802, provide effective battery life
• Boost mode if Akku less then 3.3 volt (discharged)
• Buck mode if Akku more then 3.3 volt (full charged to 4.2 volt)
• Switch automatically and provide stable 3.3 volt and allow you to use akku more effectively and long time.
• Built-in 1-cell Li-Ion/Li-Po charger
• Compact size: only 3.3 × 1.2 cm
• Current 1 A
• Perfect for low-power sensors, remote IoT nodes, and wearable devices