I used to carry smaller battery packs with me when I travelled for business to make sure I always had plenty of battery life for my phone and iPad. Then I found the Goal Zero Sherpa. Yes, it's larger than just a battery pack but it's definitely worth the extra weight. I have two Sherpas now. One I keep at my office and use it to charge my phone, headphones, and anything else that needs charging. I have another one I keep in my laptop bag for travel. I've used it to charge my laptop and phone and headphones all at once. It's a true powerhouse and I won't be without it.