I have an compaq Presario 2500 and i got an THE UNIVERSAL AC TO DC POWER/SUPPLY ADAPTER FOR HP/COMPAQ LAPTOPS from ebay, and i have to select a voltage before i use it and i don't know which one to put it at. Here is the Ac adapter specification here.



1. input volts- Ac 100V-240V 50-60Hz
2. output volts- DC 15V-21V 3A
3. power:70W Max
4. overload and short circuit protection to protect it from damage
5. Stabilized output, low ripple and low interference
6. Power LED monitor to indicate proper output setting

7. Compact size and minimum weight for easy packing and traveling.

Instruction:

1. Please make sure the DC voltage your device uses is within 16v to 20v. You can find the dc voltage on your computer or the original ac adaptor that comes with your device.

2. Find the correct connector by trying to plug it in the device. We recommend plugging the connector in the device before it is plugged into the AC Adapter.



3. Make sure the correct polarity to be used with your notebook computer, as false polarity can damage your computer. Please adjust the polarity on the detachable connector to suit your own computer.

4. Select the correct voltage (determined by your computer) just by simply moving the voltage switch button with your finger.
Please remember that the Universal AC Adapter will act as the AC adapter that originally came with your device. If you have aninternal drained battery, it will be charged by the Universal AC Adapter.
The Universal AC Adapter is also designed with a red LED, which lights up when connected to a power source.



Laptop Battery Charger for HP COMPAQ Presario 2100 2500 - eBay (item 170198719715 end time Mar-09-08 20:20:56 PDT)

seahwk83

well, i would check your original adapter to see what's written on that
look up your model and compaq support site
HP Support & Drivers
in US voltages are usually 110v - europe is 220-240v

(these are normal for countries liste, I personally do not recommend setting to these, as I have no responsibility for your machine - these are just for reference)

I would see if you could email support or find the info through google specific to your model laptop
refer to the manual to determine the proper voltage setting.
download the manual from compaq support

murshyblues

thanks for the help, i got it, the voltage for my computer model is 19v

laptopbattery

yes you should carfully adjust the voltage to fit you original laptop