Bests & Worsts Reviews from Amazon

TL;DR - If you want a USB-C fast charging power bank. Buy this. If it breaks or there's anything wrong with it, you'll get a free replacement without any hassle. I purchased the older 18W version of the PowerCore Essential 20000 PD about 6 months ago. I really just wanted something to plug my phone into when I needed it and didn't want to tie myself to a wall, like during the work day at my desk or on the couch in the evenings. I had noticed a quirk with the 18W charger where my phone would periodically stop charging, then start again. After it kept happening I decided I would shoot Anker support a message and see if I had any options, since I was well outside the Amazon return/exchange window. My first response from Anker was a pre-paid shipping return label. I dropped the charger off in the mail and they sent me a replacement the very same day, before even receiving the package I had just put out. Only about 2 days later I had a replacement in hand. The replacement worked, but had the same issue as the first one. I honestly can't say for certain if it was bad luck, an issue with the older model, an issue with the cable, my phone, or some combination of any of those things. I just decided I would live with it. It still charged my phone after all. Anker sent me an email following up asking if the replacement was working, which I didn't expect. I figured why not - I'll respond. I told them I still was experiencing the issue, but I don't want to go through any more trouble so I would just live with it. They said that wasn't acceptable, and wanted to ship me the newer version at no cost to me. Within 2 days, I received this product. I'm happy to say I haven't experienced any issues with it like I did the 18W charger. Again, the 18W charger probably works fine for most people. Whether I just have bad luck with batteries and cables I don't really know, but Anker deserves some credit for sending not only a replacement unit, but an updated version of a unit if you aren't happy with it for any reason. If only for the peace of mind, buy your batteries from Anker. If they don't work they'll send you a replacement or something better, and they won't ask you for any more money to get it to you.