Core77

[Cyberdemon]

For example I have the same HP laptop and I use 3 power supplies. The recommended power supply is rated at 150 Watts since for the big workstations they can draw a lot of power.

I think I have the same HP laptop too, an 8560w. I've been looking for an additional power supply for traveling, I think I will go with a 70 Watts, about half the price of (and smaller than) the 150 recommended by HP.

I use the older OEM HP 90w power supply that came with my old 8510W, works fine, and is 1/2 the size. Just gets scorching hot under full load...I wouldn't load up a 8 hour rendering and then leave it unattended if you know what I mean.

[Travisimo]

Sometimes laptops won't run off the smaller lower watt power brick, like my old Dell, but it will still charge from it... could be a travel option