After 7 months LG Nexus 5X now doesn't show "Charging rapidly" but only "Charging".
Ampere app shows 1700 - 2100 mA max. Overall charging time now 50% longer than initially was.
In accordance to screenshots of Ampere I see the following wattage:
4.07V * 0.89A = 3.62W
or
4.26V * 1.79A = 7.62W
Both measurements are far from 15W declared by Nexus 5X specs.
I have checked my original 5X charger with Nexus 6P phone - it displays "Charging rapidly" on 6P from my charger. This makes me to believe the issue with the phone or its battery or QC IC (Quick Charge integrated circuit).
Update:
- My charger is OK with Nexus 6P -> "Charging rapidly"
- Nexus 6P charger doesn't detected on my 5X at all -> no charge, nothing
- Switching cables on 6P charger with 6P phone -> 5X cable OK on 6P "Charging rapidly"
Conclusion: Phone Nexus 5X itself is suspected: battery or charger chip or system.