My iPhone 6s was one of the ones affected so I brought the phone in and they replaced the battery. The battery they gave me came charged at 40% (standard), shutdown at 16% and when I tried to turn it back on, it said it needed to be plugged in. When I plugged it in, the battery was immediately at 21%. I fully charged the phone to see if that was the issue and this time it shutdown at 20% and when I restarted it, it was immediately at 8%. My next step was a full system restore, and the battery died at 10% and immediately restarted at 8%. My assumption is it was human error and they accidentally put the same battery back in or something. However, I really don't want to keep going back to the Apple Store. I called them each of the times I had the issue since the battery repair (except after the system restore). Will Apple just replace my phone without much fuss, or how would you all think it'd be best to handle this situation? Thanks!