View iPhone charging rate

At my office, I have a 3rd-party wall adapter, a 3rd-party microUSB cable, and a 3rd-party wireless charging dock. My iPhone X charges slowly on this setup, compared to at home. I suspect that the cable is the weak link, but I'd like to know for sure.

I don't want to sit around with a stopwatch and measure charging rate over time, as suggested in this 2013 answer. I want to use an app or built-in reporting to see how quickly the phone is charging. Does this exist?

Solution 1:

As of 2016, it seems this was only possible using unpublished APIs (see this article), ergo impossible without a custom app.

I suspect it's gotten more difficult since as advertisers have been caught using battery levels as a form of device fingerprinting (see this article) and Apple has been rejecting apps that use accurate battery data as a result. Thus, it might not even be possible anymore to get accurate battery levels with any app on the App Store.