A compact boost converter module that turns a single-cell Li-ion battery into selectable 5V, 8V, 9V or 12V output. The input voltage must be lower than the chosen output by at least 0.5 V. Key specifications - Input voltage: 2.5 V up to VOUT minus 0.5 V - Output voltage: selectable 5 V, 8 V, 9 V, or 12 V - Maximum output current: 1 A - For 3.7 V Li battery input: 5 V at 1 A; 8 V at 0.5 A; 9 V at 0.45 A; 12 V at 0.3 A - For 5 V input: 8 V at 0.7 A; 9 V at 0.7 A; 12 V at 0.5 A - LED indicator: standard 12 V output draws about 1 mA - Low power consumption: input current < 1 mA at zero load when the display is off Benefits and practicality - Flexible power: convert a single-cell Li-ion battery to multiple higher voltages for different devices - Broad compatibility: supports common 5/8/9/12 V targets to suit various peripherals - High efficiency with low standby draw, conserving battery life - Simple integration: compact module with clear voltage selection and LED indicator Use scenarios - Power a USB device or microcontroller project from a 3.7 V Li-ion cell by setting 5 V up to 1 A - Run a 12 V accessory (such as a small LED strip or sensor module) from a 3.7 V battery at up to 0.3 A - With a 5 V supply, boost to 8 V/9 V/12 V for devices that need higher voltage but moderate current This module provides a reliable, low-power solution for portable projects requiring multiple higher voltages from a single-cell battery.