FP5139 100W DC Boost Step-up Adjustable Voltage Power Converter LED Voltmeter Boost voltage to a stable regulated output. Useful for a wide range of applications, such as powering 5V USB devices from a 3.7V lithium cell, powering higher powered electronics from a 12V battery, and a wide range of automotive and electronic projects. Constant voltage regulation, suitable for LED strips and modules, but not for raw LEDs. Input: 3-35V DC 9A, Output: 3.5-35V DC 6A, Max Power: 100W when input and output both exceed 20V, otherwise 65W. Conversion Efficiency: Up to 96%. Low input voltage or a large difference between input and output voltage will degrade the current capacity and efficiency. Dimensions: 68x42x14mm, FP5139 IC with External MOSFET, 180KHz Switching Frequency Output voltage must be greater than input voltage, do not apply reverse polarity voltage, voltmeter works only when input is >= 4V. Dedicated boost converters tend to be more efficient than buck/boost converters, so if you know that the supply voltage will always be lower than the device input voltage, a dedicated boost converter is a smart choice. The FP5139 module is small and easy to use. The built in voltmeter makes for simple installation and adjustment and helps to monitor the supply or device power. Voltage is adjusted using a potentiometer. A small button switches the voltmeter between input and output.