Modify Adafruit USB-power-gauge

I have bought this item:

I plugged my mobile, and I got these measurements:

V: 5.8 I: 528 mA Watts: 3.1
V: 5.8 I: 509 mA Watts: 3.0
V: 5.8 I: 550 mA Watts: 3.2
V: 5.8 I: 519 mA Watts: 3.0
V: 5.8 I: 532 mA Watts: 3.1

It can't be 5.8 Volt! USB cannot give more than 5 Volts. How do I fix that? Also the manufacturer gives max 2A it can measure. Can I upgrade this with hardware/software modification to 3 Amperes?

Might be more likely to get an answer in Adafruit's forums.