Default [Q] Nexus 7 Slow Charging in Thailand... Suggestions?

My Nexus 7 (2012) is taking a long time to fully charge here in Thailand. I highly suspect that the move to Thailand is the cause because in the United States my Nexus would fully charge in 2.5 - 3 hours.

My original cable and charger broke or got worn out however I have replaced the charger with another 2A charger and use an HTC Cable to charge with.

Now, here is some information I would like to know. If I were to buy an external battery pack and kept it fully charged and recharged my tablet solely from the pack would that speed up the charge time for the tablet? Is there an issue with the HTC cable? I experimented with other micro usb cables and the only cable that seems to work in the HTC cable. I know there are proper USB 3.0 micro usb cables so maybe that is the issue?