Chosen Solution

I recently replaced my battery on my iPhone 7 Plus with an Ifixit battery and I have calibrated it 4 times there are still 0 cycles (according to 3utools) and the battery percentage is still inaccurate. What can I do to fix this problem?

(It was defective in the first place)

You can try changing a battery to see if there is still this problem, which can be found in shop.rewa.tech purchase. If there is no such problem, it is the battery. If there is still this problem, it means that it is the problem of the mobile phone.