Max VDC in tends to vary between sellers but it seems the usual is up to 25 - 27VDC...the laptop charger isn't really a charger, that's it's remote PSU, the batt charging cct is usually embedded in the laptop batt itself...I like laptop PSU's because they're fanless, dead quiet and usually have a good amp output (some printer PSU's are good too), Xbox PSU's are my next fav, they're a 10 min
mod to access the 12v mains and have a 5v standby cct you can put a switch in to turn it off/on and tons of power. ATX PSU's are my least fav. they also have a standby cct but are clumsy, a little ugly and have fan noise but even a low end 350 watt one has enough output to run 10 LM2596's being vaped on simultaneously
EDIT: Just a safety tip if this is your first PSU
mod...unplug the PSU and let it sit at least overnight before you start cutting/taking it apart...those filter caps (if the discharge resistor is a little dodgy) can give you one hell of a poke, even if it's unplugged.