I'm busy at college so didn't have the chance to update the log much further.
I created a PCB to plug-in the Teensy 2.0 board and handle external power using a single cell 3.7V LiPo 4000mAh, running the Teensy at 3V instead of 5V will consume less power and give the battery roughly 6-8 days of continuous data logging to the SD card. During the experiment we experienced periodic loss of power so that's why we are adding external power source.
Also, I believe the battery powered device will reduce lots of the noise from the AC adapters.
I'll be adding more photos after I finish etching the board and soldering the components.