Chosen Solution
I replaced the battery on my iPhone 6 with an IFixIt battery and randomly it shuts off. No warning. No spinning gear. It is just suddenly off. Plugging it into power gets it to come back up pretty quickly. When it powers back up it shows that there is plenty of power. It’s happened with 20%, 40% and even close to 100%. Is this just a battery that’s a dub? Does ifixit do returns/replacements?
Contact iFixit under their customer support page. They will be more than happy to send you a replacement if your battery is faulty.
