I can highly recommend http://www.banggood.com/ZMI-QB820-20000mAh-Quick-Charge-2_0-Power-Bank-with-USB-HUB-p-1112667.html http://www.banggood.com/ZMI-QB820-2000

I can highly recommend http://www.banggood.com/ZMI-QB820-20000mAh-Quick-Charge-2_0-Power-Bank-with-USB-HUB-p-1112667.html http://www.banggood.com/ZMI-QB820-20000mAh-Quick-Charge-2_0-..., although I'm hoping someone with a thermal camera can do a proper teardown and review at some point - it gets a little warm at ~40W output. It charges my XPS 9350 just fine, so it should do the Switch no worries.