Anker has got a new collection of external batteries out and if you're on the road a lot these definitely need to be in your suitcase on your next trip. Their new PowerCore series is their smallest and lightest high-capacity battery yet with enough power to charge a variety of phones or tablets and even Apple's new MacBook 12. The batteries come in 10000-20000mAh sizes and has dual 2.4 amp USB ports (high capacity models only) for speedy charges. 

$18-$40, Amazon