The RELX Classic uses a micro USB cable, but the RELX Infinity and Essential come with Type C cables. The RELX Infinity also has an additional pogo pin for the wireless charging option compatible with its charging case and charging dock.
RELX devices are charging when the LED light pulsates white. You'll know your device is fully charged as the light stops pulsating and is a constant white. Charging to full battery capacity should take about 45-60 mins.