resistance on power adapter

my laptop requires a 19v 4.74a adapter, but my adapter got broken a few days ago so i decided to buy a new one, apparently the only adapter i can get my hands on is one that has the same voltage but different resistance (3.16a)

will my new power adapter cause harm to my laptop?

 

Hi.

3.16a is a lot lower than 4.74a , you risk damaging for power adaptor or even your laptop.

I would sell the one you bought and get a 19v 4.74a version.

Regards

John.

 

Did you buy a good brand name ac adapter?

Alex

 

its a lite-on acer adapter

 

Your fine with that adapter then

That spec is amperage

You will notice a slightly longer charge time to get your battery up to 100% , but no damage will happen to either the ac adapter or to your laptop

Btw I’m a electronics technician



Alex

 

but doesnt charge time depend on voltage? well thats what people told me, can you enlighten me please?

i have a 19v 3.16a power adapter being used on a 19v 4.74a laptop

 

3.16A is not resistance, that is the Amperage or the current output. This intern will decide the total power output (in Watts) = Volts x Amperes. A 19V 3.16A adapter can give out 60W of power while a 19V x 4.74A can give 90W.

When you disregard the battery, running a notebook with a low power adapter is more like running a desktop with an underrated powersupply, you may notice sudden lockups or crashes. But on a notebook, with a battery this will not happen since battery will act as a buffer. Theoretically it should not damage your laptop, But I don’t know the long term effects of this, especially on the batery. Always better to stick to the specification.

 

to make it more specific

old adapter
input: 100-240v 50-60hz 1.5a
output 19V 4.74a

new adapter
input: 100-240v 50-60hz 2.3a
output: 19b 3.16a

laptop:
DC 19v 4.74a
battery
14.8v 4800mah

and sorry for the confusion, different current i mean

 

Voltage on the adapter will remain constant
Amperage draw will change from as high as 3 amps to lower depending on the battery state
I have used laptops that were supplied with 8 amp adapters with 3.85 amp adapters and as I have said longer charge times result




Alex

 

As you have said not quite the same as a desktop

I would never ever run a desktop with a power supply that could cause brown-outs

However the charging buffers the missmatch and if the battery is charged fully or if the battery is older and has reduced capacity you would never tell the difference


Alex

 

but what if im using the laptop, with the 3.16a adapater, without the battery?

 

And if my advice worries’ you even a little
Adapters are cheap

When you get the chance just buy an adapter with the correct amperage specs or higher as higher won’t harm anything with the same voltage and use this adapter as an emergency spare


Alex

 

In general 60W is enough for most notebooks, 90W adapters are usually meant for charging extended batteries or for high end gaming notebooks. But if somehow your adapter fails to give the required amount of power when the notebook demands, this can lead to system crashes or some other type of unexpected outcomes.

 

yeah that's is what ill probably do, im having difficulties finding the right adapter with the right inlet, so i'll probably use this for now

thanks for the help

 

I would hate to do that
One of the benefits to having a laptop is the built-in battery acts as a uninterruptable power supply if you have line power problems


Alex

 

this is actually why i am worried, my laptop runs on a t7300 core2duo with a 8600m gt, and it has an 8-cell battery (acer 5920g), im not sure if 60w is enough

 

To be sure of 0 problems do the following

Have the laptop off and use the adapter to fully charge the battery

When fully charged unplug the adapter and run on the battery until it needs charging again


Alex