I've got an old gaming laptop which comes with a very annoyingly big brick PSU, rated at 100W and 20V. I do not care that the PSU is heavy, but it has a weird form factor, and I always have to drag it around. Looked around, and did not find any slim power units (besides, not including the PSU weight in the laptop weight spec is cheating, imho).
So I wonder if I can get four of these, seemingly high-quality, low profile PSUs, each rated at 5V and 5A (25W each), bolt them onto the laptop on the side, and wire them together to get 20V and 100W. Also, these are modular, so once the laptop dies (this thing just wouldn't die!) I would have many other uses for the PSUs. I am not quite sure how to route the AC to them -- split the cable into 4 in parallel?
There was a topic on combining DC power supplies, but I wonder if, for a laptop, I need special precautions.
Thanks in advance!