Is it okay if I charge my s9 with a 30W charger?

[MarvinGomes]

So I have an s9, and a 6 port USB charger that's 30W. I'm absolutely fine with the adaptive fast charger that came with the phone. But I need to charge a bunch of devices and so I'm out of sockets otherwise. I'm hesitant to use such this 30W charger, might damage my battery or whatnot because it doesn't recognize it as fast charging when I plug it in although charging times are similar. Also, is it safe to charge things like Bluetooth headphones and a receiver which aren't advertised to be fast charge supported using this 30W charger?

[SjorsK]

If its adaptive its probably fine. If the amount of the charge is higher than what the phone officially supports and its not adaptive the chance that you will damage your phone is certainly there.

Damaging the battery isn't the worst issue that can happen, worst case scenario the whole phone will die with a wrong charger.

The same logic applies to other devices of course. 

With chargers, always go for an official charger or a charger of a reputable high-quality brand. I highly recommend to not cut corners with those things to save a few pennies because it might be one expensive joke.