Hi,
I have a sony laptop. Which says that it needs 19.5. The DC jack was broken so I have modified the connections. The adapter I am using right now is 19V. The laptop works fine without issues. The battery is dead and doesn't last long so can't see any effects on the battery if there are any.. Do I need to worry and change the adapter to 19.5 or 19 should work fine? Any ideas?
Naheed if the thing is working ok then I would just leave it as is.
As a general rule adaptors generally put out more volts than the device that is attached to them for example cars charging system (the adaptor) will run from anything between 13.8 - 16 volts - it is the battery that will take only what it requires in volts. Another example is a good quality charger I have that charges 1.5 volt (AA batteries) at the terminals actually puts out 4.99volts so the battery is the deciding factor in that circuit.
Now most computers will require a top voltage of 12 volts +/- 5% and inside the machine will be a circuitry that will regulate what gets what whether that is 12 5 or 3,3 volts again +/- 5% - outside of that tolerance will result in non function of the machine. The only thing that I can think of is that the battery in your machine may take a tad longer to charge if it could.
See this power supply - Why do many laptops run on 19 volts? - Electrical Engineering Stack Exchange
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