24v 4a

24v 4a
Will generic car power adapter with slightly different voltage damage my laptop/notebook?

I have a Compaq Presario V5310us notebook. The AC power adapter says:

INPUT: WIDE RANGE INPUT (basically any AC in any country)
OUTPUT: 18.5V(18.5V) = 3.5a(3.5a) 65W

The generic car laptop power adapter I bought has the following voltage options:
AUTO DC POWER
REGULATED ADAPTER
INPUT: 11-14V DC 8AMP MAX
OUTPUT: (selectable) 15/16/18//20V DC 4A
22/24v dc 3.3a 80w max.

SP8II-80W

Which voltage should I select? and is there any risk?
I had been using a DC to AC inverter in the car with the AC power cable to the notebook, but this seems easier and like it might take less load on the battery?

The safest thing to do is buy a DC inverter, 300-500 watts is plenty. This makes a direct conversion to 110v AC and then you can plug your laptop powersupply directly into it and not worry about the voltage going to the laptop. However if you do not want to buy additional equipment, then you should use the 18 v setting to make sure that you don’t overvolt your laptop. The problem is you may not charge your battery when you are working this way and when you unplug it will not have any spare battery life to run. I hope this helps.

Hydrogen 24V 4A 0.5 l per min.3gp