The ones as small as a chapstick aren’t worth crap!!! I buy mine off Amazon & you might look to see if you see one that you like. Currently, I’m enamored with the “Anker” external battery. The one I preferred before this one was the “Jackery” external battery. I own both & have used the Jackery for years with great success. I’ve been very pleased with the Anker line of accessories, so I only started using their external battery this year; but I’ve been well pleased over the last 10 months & I use it almost every day!!! Some days, I’m charging my Kindle & My S8 at the same time. The Anker seems to hold a charge a few days longer than the Jackery & they are about the same MAh. Anker also sells a sturdy USB cable with 3 connectors on the end. So, I always have a TypeC, a micro, & an iPhone micro fastcharge with me ALL the time. The C fits my phone while the micro fits my Kindle & I have only 1 cable to keep up with & I have 2 devices charging at the same time. Both brands have 2 USB ports available to use. Hope you find one that you like!!!