Default [Q] Charge nexus 7 with dock?

Hello i want to know how long does the dock takes to charge the nexus 7. What %/hour does it take? i am having trouble charging my nexus7 because i think the micro usb port has become loose and the power cable wiggle a bit when plugged. I want to build a custom dock just to charge the nexus 7 via pogo pins. Apart from slow charging there is no other problem...I tried different ROMS and removed all apps to test if any app were eating juice more than expected
Tablet: Nexus 7 (2012) 8Gb ROM: Purity Rom (KK 4.4.2)
Phone : Samsung Galaxy S2 SGH-i777 (unlocked) ROM: slimbean 4.2.2 (JB 4.2.2)