My iPhone XR battery started showing erratic charging percentages, it would sometimes charge to 60% then 90% but would never go over 98% on a charge cycle. This lasted about 2-3 weeks before a charge cycle would not reach more than 12%. I was going in for surgery and shut my phone off, when I got out of surgery and attempted to turn the phone back on it went into boot loop, flashing the Apple logo every few seconds. Nothing I tried (all the Tricks mentioned online) would get the phone out of this cycle. Thankfully, I had ordered the iFixit battery kit prior to this happening and had the battery on the way. Once I received the kit, I reviewed all the directions, watched the install video online and proceeded to replace the battery. I am happy to report that the phone works perfect now and started right up after the new battery went in. The kit has all the tools and supplies needed for replacement and I am so grateful to not lose all my pictures and data on my phone.