This 12V USB charger also doubles as a voltmeter, which makes it pretty darn cool. It can support charging two USB devices at the same time, with the capacity to supply a charging current of 3.1 amps. Check out the additional photo to see the voltmeter in action. This nifty charger features rapid charge capability for iPhone, iPad, iPad Mini, iPod, Galaxy, Note 4, and the like.
• Dual USB ports
• PTTC over-current protection
• Input voltage: DC 12V - 24V
• Output current: 3.1 amps
• Voltage measuring range: 5V - 25V
• Current measuring range: 0 - 3.1 amps
• Temperature measuring range: -20 C degrees to 80 C degrees