This unique dual function DC-DC Buck step-down voltage converter and USB charger accepts 4.5V to 40V input and provides an LED voltmeter to monitor the input voltage. With input voltages from 6.5V to 40V, it will generate a regulated 5V USB output at up to 2A. This module can be powered by a battery, solar panels, or an energy storage bank, and provide the +5V regulated USB power needed to power or charge a cell phone, MP3 player, tablet, or any device that is powered by 5V USB power. It is ideal for camping and off-grid uses.

Applications:

Car / motorcycle battery voltage monitoring, solar panel energy storage monitoring or other voltage measurements.
USB Charger for mobile phone, MP3 player, Tablet PC or other electronic products.

Features:
Input voltage/ voltmeter range: DC 4.5~40V, (with input voltage from 6.5V to 40V, can generate a 5.0V regulated output)
Output voltage/current: 5V/2A Voltmeter display can be calibrated
Reverse polarity, over current and over temperature protection
Output enable button turns On/Off the USB output power.
USB power indicator LED illuminates when output is enabled
Lower Power button disables output and display and puts module in a low power mode
High-efficiency, low ripple
Dimensions: 58mm * 21mm * 10mm (L*W*H)
Net weight: 13g