What power inverter should i buy for my laptop?

Question

I have a Dell Inspiron 8500 (yes its old) laptop. I have a program and device to do gps with it but my computers battery doesnt last long enough to use on a trip without a power source. I need an inverter but i am not sure what size nor brand to buy b/c ive heard that they can mess up your computer if you get the wrong one. My power pack is a PA-10 ac adapter and says
Input : AC 100-240V ~1.5 A, 50-60hz
Output: DC 19.5 V, 4.62 A

Is there a certain wattage of inverter i should buy?

thanks

Answer 1

Anything from 100 to 240 V will do the job, in practise computer power supplies can tolerate some pretty crappy power so whilst a sine wave inverter would be better you should be fine with a square wave unit (and frequency doesn't really matter all that much to switchmode power supplies). If the inverter is good quality and doesn't send nasty spikes to the power supply I don't see it destroying your laptop.

Buy a big inverter though, you can probably expect your laptop to use up to about 190 W or so and the adapter will lose some power to heat (touch it after prolonged use if you need any proof of that) so I'd go with at least a few hundred Watts rating (the adapter is rated at about 90 W but despite what an idiot claiming to know what he's talking about said, you need to allow for it to use more since the adapter will put out less power than it takes in, he must have been sleeping through physics).

Of course if you want to run anything else off it then you'll have to get an even bigger inverter.

As for getting another battery for your laptop, if it's old don't bother as the batteries will be 'new' old stock and so probably already dead when you buy one (they lose capacity just sitting on the shelf).

Answer 2

Laptop Power Inverter

Answer 3

To find out how many watts your computer reqiures to work, a little trick is to multiply the output Volts x Amps. Which in your case it's

19.4 x 4.62= 89.6 Watts. (formula is derived from ohms law)
http://en.wikipedia.org/wiki/Ohm's_law

A good 90 Watt inverter would suffice, this would actually keep about 110 watts at the output, the power (heat) loss is compensated by the extra wattage, but nothing much bigger than that, it is just not needed for what you are trying to power.

They have power inverters at any electronics store. Targus is a decent brand, ( it will keep the power output constant) however there are many others.

Have a great night!

Answer 4

get a decent size one 1000 watts continuous should do. if you get larger that you need then you will have less trouble when it loads. If you are going to run you laptop off it directly you will need one with pure sine wave output, not modified sine wave. Plus look for one with the least total harmonic distortion. The best thing to do is get another battery for you laptop and then you can get a cheaper inverter and use it to recharge batteries. Remember a converter rated at 1000 watts continuous will not power something that needs a 1000 watts. Actually it with only power something up to about 350 watts.

Answer 5

If it is a really cheap inverter, you could potentially damage it, but that is still rare. You will not need a 300watt inverter, that adapter should pull no more than 60watts.

Answer 6

Yes, one that is a close match to the adapter wattage of your laptop charger.

Answer 7

You need one that matches the output voltage, current and polarity of your power supply.