WeMos D1 ESP Wroom 02 Board ESP8266 Mini WiFi Nodemcu Module 18650 Battery

WeMos D1 ESP Wroom 02 Board ESP8266 Mini WiFi Nodemcu Module 18650 Battery integrates a high-performance ESP8266 Wi-Fi microcontroller with an onboard 18650 lithium-ion battery charging and boost circuit onto a single compact development platform. This versatile module features the reliable ESP-WROOM-02 core, enabling seamless wireless communication alongside efficient power management provided by the integrated TP5410 IC. Consequently, creators can power remote Internet of Things (IoT) nodes directly from a standard 18650 cell without needing external power management hardware. Furthermore, the board includes a built-in battery charging system that operates simultaneously with device execution, providing continuous power redundancy. Therefore, this integrated solution greatly simplifies portable electronics design, allowing you to deploy self-sustained wireless sensors and smart home controllers with maximum efficiency.

Key Features:

• Integrated Battery Holder: Accommodates a standard single-cell 18650 rechargeable Li-Ion battery directly on the rear of the PCB for portable power.
• Onboard Charging Circuitry: Features a TP5410 charging system that manages battery top-up and provides a regulated 5V boost output concurrently.
• Comprehensive Protection: Includes integrated overcharge and over-discharge safety mechanisms to safeguard connected lithium-ion batteries.
• Programmable Status LEDs: Utilizes visual indicators for charge state monitoring (Red for charging, Green for fully charged) and offers a user-programmable LED tied to GPIO16 (D0).
• Power Control Switch: Integrates an onboard slide switch to easily control system power without removing the battery cell.
• Deep Sleep Solder Pad: Provides a dedicated solder terminal to connect GPIO16 to RESET for ultralow-power deep sleep sleep cycles.

Technical Specifications:

• Wireless Microcontroller: ESP-WROOM-02 (ESP8266-based architecture)
• Operating Voltage: 3.3 V (System logic level)
• Input Supply Voltage: 5 VDC via Micro-USB interface
• Charging Current: ≈ 500 mA
• Analog Input (ADC): 1 Channel (0 to 1 V range with onboard voltage divider: 220 KΩ – 100 KΩ)
• Wi-Fi Protocol: IEEE 802.11 b/g/n operating at 2.4 GHz
• Flash Memory Size: 4 MB (32 Mbit)
• USB-to-Serial IC: CP2102 or CH340C bridge IC for fast code flashing

Mechanical Specifications:

• Substrate Material: High-grade FR-4 Fiberglass PCB
• Battery Connector Type: Surface-mount 18650 cell holder clips
• USB Connector: Standard Micro-USB Type-B Female
• Mounting Holes: 4 x M2.5 mechanical mounting holes for easy enclosure integration

Dimensions:

• Overall Length: ≈ 92 mm
• Overall Width: ≈ 26 mm
• Overall Height: ≈ 20 mm (including battery holder)
• Net Weight: ≈ 25 g (without battery)

Pinout and Wiring:

• 3V3: Regulated 3.3 V output pin for powering external low-power sensors and peripherals.
• 5V: Regulated 5 V output pin supplied by USB power or the onboard 18650 boost converter.
• GND: Common system ground connection point.
• A0 (ADC): Single analog input channel connected through an internal resistor network.
• D0 to D8: General-Purpose Input/Output (GPIO) pins supporting I2C, SPI, PWM, and 1-Wire protocols.
• TX/RX: Universal Asynchronous Receiver-Transmitter serial communication pins connected to the USB converter interface.
• Usage Precaution: However, take strict care to respect battery polarity markings, as reversed battery insertion will permanently damage the TP5410 charging controller.

Datasheet Reference:

• Download ESP-WROOM-02 Datasheet

Commonly Used in:

• Standalone IoT Nodes: Powering wireless environmental monitor stations without dedicated AC wall power.
• Battery-Powered Wearables: Driving portable Wi-Fi data logs and smart wearable prototypes.
• DIY Home Automation: Operating smart switch controllers and remote telemetry gateways across local networks.

Applications:

• Remote Weather Stations: Reading temperature, humidity, and barometric pressure sensors while running in deep-sleep mode.
• Asset Tracking Systems: Transmitting Wi-Fi signal metrics and location data in mobile tracking setups.
• Wireless Alarm Monitors: Sending push notifications via MQTT or webhooks whenever motion sensors detect activity.

Equivalent Models:

• NodeMCU V3 ESP8266 + Battery Shield: A modular two-board combination that yields identical Wi-Fi and power functionality.
• ESP32 18650 Battery Development Board: A dual-core upgrade providing enhanced processing performance, Bluetooth capability, and 18650 power integration.
• WeMos D1 Mini + LiPo Battery Shield: A smaller form-factor alternative designed for flat pouch lithium polymer batteries instead of 18650 cells.

Package Includes:

• 1 x WeMos D1 ESP Wroom 02 Board ESP8266 Mini WiFi Nodemcu Module 18650 Battery