Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is it safe to use these chargers to replace my lost laptop charger?

Original charger: 19V, 4.74A

  • Replacement 1: 19V, 4.5A
  • Replacement 2: 20V, 4.5A
share|improve this question
The first one should do nicely. I use a similar one for two years now. – Rook Nov 10 '10 at 3:05
@rook - ok thanks. i was thinking the power might not be enough if i was using the first one. – Quazzar Aznolage Nov 10 '10 at 3:12
It is always better to go a little over on the voltage and amperage than it is to go under. It will be safe enough, but you might kill your battery sooner. – MaQleod Nov 10 '10 at 3:18
@MaQleod - thanks. I have no choice but to use the charger anyways so might as well sacrifice battery life. – Quazzar Aznolage Nov 10 '10 at 3:25

A replacement must be the same voltage. Too little, and the battery won't charge. Too much, and you'll fry something.

The amperage should be the same or higher. If it's too much lower, it either won't work, or the adapter will overheat making the attempt to power the laptop. If it's higher, the laptop simply won't use the extra available power.

share|improve this answer

Either charger should work fine. The only difference is it will take very slightly longer to charge the battery than with your original charger. There's no adverse affect on battery life from the lower amperage. IF anything it might last just a bit longer since the heat generated (and dissipated inside the battery compartment) will be slightly less. But we're talking a very small amount here - less than 1% I would think.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .