Overview
This Lithium Battery Shield turns four 18650 lithium cells into a working DIY power bank. Built-in protection circuitry (overcurrent, overvoltage, and undervoltage protection) keeps charging safe, and the module outputs two voltages — 5V/3A for powering USB devices and 3V/1A for lower-voltage projects — so it works equally well as a phone charger or as a power source for Arduino, ESP32, and ESP8266 boards.
Note: Batteries are not included and must be inserted with correct polarity — the board is clearly marked positive and negative, and incorrect installation can damage the module.
What This Battery Shield Does
- Holds four 18650 lithium cells to build a working DIY power bank
- Outputs two voltages: 5V/3A for USB devices and 3V/1A for low-voltage projects
- Built-in protection IC guards against overcurrent, overvoltage, and undervoltage
- Micro USB charging input at 600mA–800mA
- Powers Arduino, ESP32, and ESP8266 boards directly, in addition to standard USB devices
Specifications
Specification
Value Output Voltage 3V / 5V Output Port Type USB or Expansion Input Port Micro USB Conversion Efficiency 95% Length 100 mm Width 90 mm Height 20 mm Weight 71 g Battery Capacity Supported Up to 4× 18650 cells Battery Voltage Range 3.2V – 4.2V Battery Installation — Read Before You Power It On
Important: Battery polarity must be correct before use. The board is clearly marked positive and negative — installing a battery backwards will burn out the module. Batteries are not included and must be purchased separately.
Need 18650 cells to go with it? See our 3.7V 18650 lithium rechargeable battery.
What Can You Power With It?
- A DIY portable power bank for phones and USB devices (5V/3A output)
- Arduino, ESP32, or ESP8266 projects needing a battery-backed 3V or 5V supply
- Portable electronics prototypes that need to run off rechargeable cells instead of a wall adapter
Frequently Asked Questions
Does this module include the 18650 batteries?
No. The shield holds up to four 18650 cells, but batteries are sold separately.
What happens if I install a battery backwards?
The module will be damaged. Always match the positive and negative markings on the board before inserting a battery.
Can I use this to power an ESP32 or ESP8266 project directly?
Yes — the 3V/1A and 5V/3A outputs both work as a stable power source for Arduino, ESP32, and ESP8266 boards, not just for charging phones.
How fast does it charge the batteries?
Charging current through the Micro USB input is 600mA–800mA.
Looking for more Arduino boards and power modules? Browse our full Arduino Boards & Shields collection.