Let's say I have my laptop charger that uses 19.5V and 3.9A and I want to use it in other laptop that has no charger but it needs just 19V and 3.16A, I've studied a little of electtronics and I know that the amperage doesn't affect because the computer will use just the necessary, but I'm not really sure about the voltage.

I read this post and I know the polarity is the same and the connector fits, but it doesn't say anything about voltage, I also know if the voltage of the charger were lower than the specification it'll not be a problem, but what about this little almost insignificant difference??