I think this amusing photograph says that in the name of science I am quite prepared to look stupid for 30 seconds whilst I check the polarity of my new CoolerMaster SNA 95 Power adapter.
Actually it is all HP's fault. The HP Envy 15 which is now about 1 year old comes with possibly the worlds largest Notebook power adapter.
To be fair when you are running an Intel i7 processor with 8 threads, 8GB memory and a 1920x1080 screen you are going to have to make some sacrifices in power consumption. But there is no excuse for not writing the polarity of the power plug on the end of the HP power brick.
Probably it is a sort of standard, but hey, I thought it was worth getting out the multimeter, the crazy magnifying glass headset to check it all out. So yes the outside is negative and the inside is positive and the voltage is 19V.
It is currently charging (with at least one ominous message) we will see if it can manage to complete the charge since this 95W adapter is underpowered compared with the gargantuan 120W of the original HP adapter.