18.5 volt vs 19 volt vs 19.5 volt charger

Should these all these chargers be compatible with each other (obviously the machine that ships with a larger charger might not be optimal with the smaller charger) They all have the same plug.

609939-001 18v, 65w
609940-001 19v, 90W
645156-001 19.5v, 120W

I want to use 120W or 90W (larger) adapter with a machine that ships with 65W adapter. I see for e.g. 8440p is listed for both 90W and 120W chargers.... not sure why the voltage is different?

 

More Watts of the power supply is always no problem (even better) but the voltage should be equal, 0.5v is within the tolerance but as far as I know 1.5v is too much.

However, I am not the expert and maybe someone with more knowledge can confirm?

 

HP sells those power adapters as smart ac adapters, and i think that the higher voltages are better suited for the more power hungry machines. I also come to think that the properties of the smart ac adapters allow them to be used for all the newer HP Notebooks ( since 8510 series i guess), and it won´t matter if they are 18V, 19V, or 19.5 V.

This is what HP says about the "smart" adpaters :

here´s a table with the specs of the different smart ac adapters. i highlighted the output current limitation. those adapters will shut down for example at a surge with a dc output of 29V. This would mean that the notebooks can handle safely more that 20V.



From my experience:
I own one 90w and one 120w smart adapter ( both 19V) from my old 8510p, and another 200w smart adapter ( 19.5V)for the 8560w.

i have used and tested all adapters for both machines and every combination works well.
the 8510 ( power drain under load ~90W) works well with he quite new 200w brick and in return when i travel i use the 90w power adapter for the 8560w.
The 8560w uses under maximum load around 120-130W, so when i´m travelling i try not to do CPU-Based rendering or other tasks that push the machine to it´s maximum.

Since Hp did intend the smart adapters to be used on all systems (since 8510 i guess) you should be fine with every choice. Maybe you should look how much energy your 2530p uses under maximum load and make your decision based on the required energy and weight of the smart adapter.

 

So I took the 65w adapter from the 2530p and plugged it into the 8560w and it works, but shows a message that it's recommended/optimal to use a larger power supply. I then tried the 120w (19.5v) from the 8560w on the 2530p and it also seems to work.

The issue I was having was a 90w 19.0 v adapter wouldn't work on the 2530p, it seemed to work for a few minutes and then the power light started blinking. I didn't notice the difference in voltages at first and just assumed all the genuine HP chargers with the same plug would be compatible.

I then took a spare 8560w charger to my office and plugged it into the "2400 series" docking station I use with my 2530p (confused yet?) and it seems to work, only I haven't docked the laptop yet... will find out later today.

So my conclusion is the 90w 19.0 volt adapter I had laying around (not sure what it shipped with) is simply defective.