I have a laptop that is 110v-240v with 6.32a. I am going out of the country and can only find adapters that say 100v-250v with a 2.5a max. What impact will this have on running my computer? Or is there an adapter that matches the amps I have?

  • What type of adapter are you referring to?
    – Moab
    Mar 20, 2016 at 2:16
  • 1
    It's a travel adapter, specifically Targus World Power Travel Adapter
    – lisa
    Mar 20, 2016 at 2:17
  • 1
    Normally you should get an adapter that has an ampere rating at least as high as the equipment states. Anything less and you may not be able to power up the device, or it may start behaving badly. Mar 20, 2016 at 2:23
  • science.howstuffworks.com/environmental/energy/question501.htm - Without enough amps your laptop will not be able to draw enough power to charge.
    – LawrenceC
    Mar 20, 2016 at 2:23
  • 1
    -1 surely you should know that amps are an electronics concept.. you don't come to a computer question site and ask an electronics question(as you have in your title),.. and the body of your question is a bit different to your title.
    – barlop
    Mar 20, 2016 at 3:12

2 Answers 2


Your existing 110-240V power supply is designed to work in any country except Japan. Though it probably will also work in Japan as well, though it may not work at all. If it doesn't work at all it won't damage anything.

Power supplies have input and output voltages, and input and output amps maximums. 100-240V is the range of allowable input voltages. The rating of 2.5A and 6.32A is the output amps maximum allowed.

The power supply needs to be able to provide an output amps at least the output amps of the old one. 2.5A power supply is not enough to work like your old one. If the power supply is not rated for enough amps it will overheat and burn out components or it will trip the overload protection if it has one to protect itself.

When going to a country/region with a different supply voltage only the input voltage and frequency needs to be in range. 100-240V power supplies are designed to be used in any country. Japan is the only country that uses less than 110V.

There are some laptops that are able to detect what amount of power the power supply can provide and adjust its usage accordingly, by not charging the battery so fast, and not allowing the cpu to run as fast as it can.

  • Anecdotally but empirically, I've never had any issue in Japan with any equipment rated as 'dual voltage' even if it only said 120-240v
    – Tetsujin
    Mar 20, 2016 at 17:12
  • I'm not surprised. Due to mains power usually only being within 10% of the nominal voltage anyway, device manufacturers have to deal with that variation anyway. The difference between plugging a device expecting 120V into a mains with 100V +/- 10% outlet may work and just be more susceptible to brownouts. Mar 20, 2016 at 23:33

Amps is short for Ampere, which measures - in laymans terms - the amount of current or power that flows.

If you have a connection with not enough power, it will just not work or start to overheat and burn - both not recommendable.

  • 1
    What do you mean by "current or power"?! Current and power are completely different concepts. Mar 20, 2016 at 6:06
  • 1
    Current and power are closely coupled. Since Watts=Current * Voltage, if voltage is fixed, then current (amps) is directly proportional to power (watts). It is thus correct to say that if the connection does not have enough current it will not work..., and the same thing can be said if it does not have enough power. I do agree this is not a great answer though.
    – davidgo
    Mar 20, 2016 at 7:24
  • @davidgo -- Just because there's a mathematical relationship does not mean that you can interchange the words. (velocity)=(distance)/(time), so if a policeman ask you "do you know how fast you were driving?", are you going to reply with a distance or time value? It's because of ignorance about the proper meaning of these electrical terms that sloppy explanations exist.
    – sawdust
    Mar 20, 2016 at 10:00
  • 1
    @sawdust - conversely I would have a poorer understanding of the world around me if the smart guys who can handle the maths did not oversimplify the results to a level I can grasp. The OP did say "In laymans terms". (and if a policeman asks me how fast I was driving It would be foolish to reply, although if I were pushed, I would attempt to say that I was at XXX location XXX km's away at YYYY time, which could both answer and be more likely to evidence then an instantaneous speed - and less likely to incriminate me)
    – davidgo
    Mar 20, 2016 at 10:09
  • @DavidSchwartz , I tried to make the answer simple so a non-electrician can understand it. As end-users typically have no control over the voltage and it is constant and given, the current is a direct measure for the power used. I could have written it more 'correct', but I doubt it would have been more helpful for the asker.
    – Aganju
    Mar 21, 2016 at 11:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.