The HKD Micro USB 4 x 18650 Battery Holder/Charger Protection Board V3 is a compact, multifunctional power management solution designed for DIY electronics, portable power projects, IoT systems, and embedded applications. This module combines battery holding, charging, protection, and power output into a single integrated board, making it ideal for building rechargeable power banks, backup power supplies, and mobile electronic projects.
Designed to support four 18650 lithium-ion batteries, this board provides intelligent battery protection features, including overcharge protection and over-discharge protection, helping to extend battery lifespan and improve system safety. It ensures stable and reliable power delivery while protecting both the batteries and connected devices from damage caused by incorrect voltage levels.
The board features a Micro USB input port for charging and power input, making it easy to power using common USB chargers, adapters, or power banks. A Type-A USB output port allows you to use the system as a portable power source for external devices such as microcontrollers, sensors, development boards, and small USB-powered electronics.
Charging is managed at 0.5A current, providing safe and stable battery charging performance. A single onboard switch allows easy control of the USB output, giving users manual power management without needing external switches or controllers.
For flexible power distribution, the board includes:
- Three 3V output ports for low-voltage electronics and microcontrollers
- Three 5V output ports for standard USB-powered devices and modules
This makes the board highly versatile for powering multiple circuits simultaneously in robotics projects, Arduino systems, ESP-based devices, IoT nodes, and portable electronics.
An LED status indicator system provides clear visual feedback:
- Red LED = Charging
- Green LED = Fully charged
This allows easy monitoring of charging status without external instruments.
The compact PCB design makes it easy to integrate into custom enclosures, DIY power banks, robotics platforms, and embedded systems. It is especially useful for makers, hobbyists, students, and developers working on battery-powered projects.
Key Features:
- Supports 4 x 18650 lithium-ion batteries
- Micro USB input for charging and power supply
- Type-A USB output for powering external devices
- Overcharge & over-discharge protection
- 0.5A charging current
- Onboard power switch for USB output control
- Multiple regulated outputs:
3 x 3V output ports
3 x 5V output ports
- LED indicators:
Red = Charging
Green = Fully charged
- Compact and lightweight design
Ideal for DIY power banks, portable power supplies, robotics, IoT, and embedded systems
Electrical Specifications:
- Input Voltage: 5-8V
- Charging Current: 0.5A
- Output Options:
3V / 1A output
5V / 2A output
- USB Output: Type-A USB
- Charging Input: Micro USB
- Size: 9.8 x 2.9cm (3.86 x 1.14 inch)
Important Safety Notes
Battery polarity is critical
- Always follow the "+" and "-" markings on the PCB
- Incorrect battery orientation will destroy the charging chip
Batteries not included
- This product does not include 18650 batteries.
This 4 x 18650 USB Battery Holder/Charger Protection Board V3 is the perfect all-in-one power solution for anyone building portable energy systems, rechargeable power projects, DIY electronics, and mobile embedded applications, delivering safety, flexibility, and reliability in a compact design.
What's in the box
1 x HKD 4x18650 USB Battery Holder Charger Board with Protection V3
