I bought this one recently and it has been fantastic. Charge time is about 2 hours from zero I would guess. The "sweet spot" is just to center the phone on the pad.

http://www.amazon.com/gp/aw/d/B019WEURSY/ref=mp_s_a_1_1?qid=1464614018&sr=8-1&pi=SY200_QL40&keywords=aukey+qi&dpPl=1&dpID=31TbE36w9XL&ref=plSrch

https://www.amazon.com/Aukey-Wireless-Charging-Qi-Enabled-Devices/dp/B019WEURSY/ref=sr_1_1?ie=UTF8&qid=1504283870&sr=8-1&keywords=aukey+wireless+charger