It was nowhere stated that the product doesn’t include a power supply. It’s powered via USB (charger). It’s definitely not true that it runs from mains! A power supply or charger would have to be included!! It uses 5V DC and the current draw is unknown.It doesn’t remember my preferred flashing/steady mode, so I have to switch modes several times every time.
I bought the cars for my grandson and we're very satisfied! I like that they have no sharp edges, can be linked together, and he can play at home or outside in the sand. My grandson really likes them.