I just bought a minibook x n5100 since the day it arrived the battery does not charge 100%. I already tried with the original charger in port 1 and in port 2 with a PD 45 watts and it is the same, sometimes it stays at 34%, other times at 43%. I opened it to have it inspected, it is visually fine, the battery is not inflated or anything obvious.
It is better to send it back before the 14 days to replace or refund have passed. If you are from Europe write to store@chuwi.com, if you are from other area service@chuwi.com. Do not wait.