Both the AUKEY 3000mAh Type-C Power Bank (PB-Y3) and the LG G6 phone support charging using Qualcomm Quick Charge 3.0 technology so let's see how well they work together when connected over USB Type-C.
The AUKEY charger's USB Type-C port claims to output 15 watts (5 volts @ 3 amps) to charge the LG G6 on a fully drained battery. Charging however can be seen to vary between 6 watts (5 volts @ 1.2 amps) and 8.5 watts (5 volts @ 1.7 amps) with never a stable charging current. It's not normal for current to keep on falling to zero and jumping back up so periodically during charging.