Question: is 5 watts good for charging?
Answer: For wired, USB charging, the most common chargers will provide 5W (1A at 5V), which is sufficient for most smartphones today. Better is a 10W (2A at 5V) charger. Wireless chargers are rated up to 15W for the recent specifications, although many devices will only charge at 5W, 7.5W or 10W.