LilyPad LiPower 5V

SKU: FA1033-3
Input Voltage Source

Single Cell 3.7V LiPo Battery (nominal voltage)
Input Connection

JST Connector & Sew Tabs
Output Voltage

Regulated 5V DC
Output Connection

Sew Tabs (+ and -)
Max Output Current

Varies by manufacturer (Typically 200mA to 500mA maximum)
Low Voltage Cutoff

Approx. 3.0V (protects battery from over-discharge)
Dimensions

Approx. 20mm (0.8") diameter
Efficiency

Typically 80%–90%
LilyPad LiPower 5V
The LilyPad LiPower 5V is an essential power management board designed for use in wearable and e-textile projects. It is a simple yet vital component that enables the use of standard single-cell 3.7V Lithium Polymer (LiPo) batteries to power your entire LilyPad circuit at a regulated 5V output.
This board simplifies battery integration by providing a JST connector for the battery input and clear, sewable tabs for regulated 5V power and ground output. It is a foundational component for both hobbyists and businesses creating portable, reliable wearable electronics.
Description
Powering wearable electronics can be tricky, as most components prefer a steady voltage (typically 3.3V or 5V), but batteries run down over time, dropping their voltage output. The LilyPad LiPower 5V solves this problem by taking the variable input voltage from a single-cell 3.7V LiPo battery (which ranges from about 4.2V when full to 3V when empty) and boosting it to a consistent, regulated 5V output.
This regulated 5V is crucial for components that require precise voltage, such as 5V microcontrollers (like the Arduino UNO R3) or certain sensors and actuators. The board maintains this output until the battery voltage drops too low, at which point a built-in low voltage cutoff circuit safely shuts down the power to protect your valuable LiPo battery from deep discharge damage.
Designed within the standard LilyPad philosophy, the board features a circular profile and large “sew tabs” labeled for input (battery) and output (5V power). Connections are made using conductive thread, ensuring seamless integration into fabric projects without bulky wires. The small size, high efficiency (typically around 80-90%), and robust design make it an indispensable tool for building professional, battery-operated wearable projects.
Features
  • Voltage Regulation: Converts variable LiPo battery voltage (3.7V nominal) into a constant, regulated 5V output.
  • LiPo Protection: Includes a low-voltage cutoff circuit to safely protect 3.7V LiPo batteries from damage caused by over-discharging.
  • Battery Connector: Features an on-board JST connector for easy plug-and-play connection of standard LiPo batteries.
  • Sewable Design: Utilizes large “sew tabs” for secure integration into e-textile projects using conductive thread.
  • Compact Form Factor: Small, circular, lightweight design optimized for wearable applications.
  • Efficient Operation: High efficiency typically maintains stable 5V output as long as the battery has sufficient charge.
  • Simple Interface: Clearly labeled input (Bat) and output (5V) tabs for easy wiring.
Usage
The LilyPad LiPower 5V is used whenever a stable 5V source is needed for a battery-powered e-textile project:
  1. Powering 5V Microcontrollers: Provides a stable 5V source for older 5V Arduino boards or other components that require exact voltage input.
  2. Driving High-Power LEDs: Ensures a consistent voltage to drive LEDs or other actuators at a stable brightness.
  3. Portable Projects: Used in any mobile or wearable project where wall power is unavailable and a standard LiPo battery is the power source.
  4. Commercial Prototypes: For businesses developing durable, battery-operated prototypes that require robust power management features like low-voltage cutoff.

Simply plug a 3.7V LiPo battery into the JST connector. Sew the ‘+’ 5V output tab to the power input of your LilyPad microcontroller or components, and the ‘−’ output tab to the ground connection using conductive thread.
Q: Do I need a separate battery charger for the LiPo battery when using this board?

Yes. The LilyPad LiPower 5V is a voltage regulator and protector, not a charger. You will need an external LiPo charger board (like a dedicated SparkFun or Adafruit charger) to recharge the battery when it runs out of power. (Note: The LilyPad USB board has charging built-in, but this specific LiPower board does not.)

Q: What is the maximum current output I can draw from the 5V line?

This typically varies by the specific model’s boost converter chip used by the manufacturer, but most versions provide between 200mA and 500mA of continuous current. Ensure your total project current draw stays below this limit.

Q: Why do I need this if my battery is 3.7V and my board runs at 3.3V or 5V?

The 3.7V is the nominal voltage; a LiPo battery voltage drops as it is used. This board ensures a steady 5V output even as the battery drains, preventing brownouts and protecting the battery from permanent damage when it hits a critically low voltage.

Q: Is the board washable?

Like all LilyPad components, it can be hand-washed if the battery is completely removed and the entire circuit is allowed to air dry fully.

Q: Can I use standard AA batteries with this?

The JST connector and cutoff circuit are specifically designed for single-cell 3.7V LiPo batteries. AA batteries use different chemistry and voltages (typically 1.5V each) and are not compatible with this board’s input or protection features.

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