Yes, a portable power source probably would be a good idea so suggestions welcomed, thanks!
Sorry it took me so long, wifi issues...
18650 power box | eBay
These are an excellent deal, but not not all of them are the same.
If you want to use it for other purposes than just charging, like vaping with a true 5V passthrough, you'll want one that has an output of at least 2.0-3.0 amps.
Also, do not use 18650 protected cells in these as the unit already has a protection circuit built in. It also has a voltage regulator and several other safety features. One even has a mini-flashlight in it.
And if 10,000+ mah is too big for you, I can provide you with several other inexpensive options. Just lemme know.
And an example of the batteries you'll need:
http://www.ebay.com/itm/2pcs-TrustF...614351477?pt=US_Batteries&hash=item35b1afbe75
I prefer Trustfire over Ultrafire as they last longer and are less expensive than Ultras. There are hundreds of vendors on eBay for lithium batteries so should shop around and see whose got the best price for the cells you need.....NON-PROTECTED. I just used this vendor as an example on a quick search, but there are tons all over eBay.