What's the best portable battery charger for a MacBook?

I have a personal hotspot and love working outside but I’m limited to how much battery my MacBook has. Has anyone used/or is currently using external battery for their MacBook?

I assume you’re talking about the Macbooks with the Magsafe power adaptors as the new Macbooks can now be charged with any USB powerbank (in that case, I recommend the Mi Power Bank for the best bang for your buck - http://www.mi.com/en/mipowerbank10400/)

Regarding the traditional Magsafe battery chargers, there aren’t that many on the market due to Apple being jerks about letting others use their plug design. The best option I’ve tried is the Hyper Juice however that involved cutting an existing power adaptor which may scare off some people. - http://www.hypershop.com/HyperJuice/2-External-Battery-for-MacBook-iPad-iPhone-USB-100Wh/

The Macbook itself has a great battery - if yours is dying whilst you work outside for a few hours it might be in need of replacement which is cheaper and lighter than getting an external pack. Well, unless you’re like me and do processor-heavy tasks that kill batteries fast.

I haven’t looked into this yet, but my tip would be to have a look at the leading products on Amazon and read the reviews left by customers, they usually are extremely insightful

Anyone tried: https://www.getbatterybox.com ?

+1 for the Xiaomi power bank. Very high quality powerbank. The released a 2nd generation featuring a bigger model with 16000 mAh.