Not The Average "Without Battery / AC" Question, More Technical...

Hi,

I know there are plenty of threads about running without battery on AC, and I've read many of them, including the battery guide. There are different opinions about this, however it seems like no one has mentioned anything about the "power output" capability of the transformer(AC adapter). I was in another debate and some interesting technical numbers has arisen, and I want to hear some opinions from some of the experts here.

It seems most notebooks today come with an AC adapter that's capable to output from 75W to 90W, depending on the brand. Someone mentioned about the battery is supposed to act like a capacitor because most AC adapter cannot handle a notebook running in full load for a longer period of time. If you add up the wattage numbers from the devices in your notebook, the total wattage can be greater than the output of the AC adapter, I mean at bare limit or over by a little. So if this is the case, is this mean there is a chance of frying your AC adapter or notebook when using the AC adapter alone without the battery?

Any expert opinions on this?

Thanks.

 

I'm by no means an expert, but... no. no. no. no. no.

If any notebook does this by design, it is a design flaw. No laptop I've seen cycles the battery because the AC adapter can't handle the load (for example, if you connect a 65W adapter to a notebook requiring a 90W adapter, it will tell you that the adapter is of too low a wattage and will run at a reduced speed instead of using power from the battery.)

So use your laptop without the battery in. I've done it countless times with my Latitude D600 and a 65W adapter. Nothing's happened.

(Although for daily use, I still leave the battery in so I can grab the laptop and go quickly)

 

I know what you mean, this is what I always thought also. But the person wasn't thinking about that big of a difference in wattage. From the numbers we have added, it seems like it can be at the bare limit or just over a little, for example, 85W adapter and the notebook is using maybe 90W if you turn everything on, wifi, bluetooth, running heavy tasks, etc.

 

Anyone else can voice their comment?

Thanks.

 

Batteries are resistive based capacitors, but the information you read is wrong. The Ac power adaptor is designed to output more power than the maximum power the laptop can use. AKA, the ac adaptor will still have spare power, even when charging the battery, and running at 100% power.
Their is a separate circuit on your motherboard, which charges the battery, so do not worry about frying your ac adaptor.
Just do not keep the ac adaptor under clothing or something like that, cause than it will overheat.

K-TRON

 

I agree with above but will say there are known issues where using the laptop while charging the battery will increase the charging time. That is because of a under powered adapter/power brick. This will not effect the issues you are concerned with in any way. The system gets first grabs on the available power batt second, and it will not go beyond it's capacity. So as K-T said, all is fine. I do not remember but one notebook I believe a DeLL made you order a 95w adapter vs 65w if you (can't remember) ordered blu-ray?

 

You should search for my c90s power test.

I showed that the c90 was able to pull over 100w of power from a 90w adapter and when I upgraded to the 120w adapter it was able to pull like 116w.

People did have problems without a battery with the smaller adapter because the situation is like what you were looking for, the amount of power needed was not enough from the A/C so it used the battery to stay going. But with the 120w you can run with no battery just fine.

the c90 is one of the most super power hungry laptops around tho with a full fledged desktop cpu and alot of other things, any normal laptop would be just fine and you can expect probably about 10% more power peak from your A/C adapter than what its rated.


edit: here you go its my old post I think its almost directly answering what your asking. I dont blame you for not finding it in a search it was hard me to find it even :x
http://forum.notebookreview.com/showthread.php?t=219507

 

K-TRON, powerpack, and ViciousXUSMC,

Your info is exactly what I was looking for, thanks again.

ViciousXUSMC, excellent benchmark thread!

 

stewie, I have to point out that the C90 is clearly a badly designed system (sorry VXUSMC) as the power supply is short, it is sooo temperamental with RAM VXUSMC can't run a 2GB stick. I mean great it has a desktop CPU but clearly rushed to market early. So as K-T said and I followed, in general you should not have issues unless someone built a poorly designed system, but even then don't worry about most issues you are concerned with. I believe on those even the C90 would be fine, "overdrawing" on the powerbrick.

And stewie, quite trying to kill your mom and take over the world!

 

mmm... What are these? Pancakes? Oh oh, these are delectable. powerpack, good news! I've decided not to kill you! :laugh:

 

No insult here I love my c90 but all the points you just made I pretty much already stated.

I made a point to say the c90 is a super power hungry machine and that any normal laptop would be just fine.