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View Full Version : Can we run laptop on AC power continuously ??



chinmaya_n
June 25th, 2011, 04:56 PM
Hi,

I wanted to know can we run a laptop with AC power ( power card ) for long time like 5-7 hours.
i.e meanwhile the battery gets charged with in 2 hrs but I continue using with AC power only. Does this affect my battery...?

I heard that it would be recommended to use laptop in AC power as it uses AC power directly after the battery is fully charged so that battery can be used when not connected to power.

ThankU

Paqman
June 25th, 2011, 04:59 PM
Does this affect my battery...?


Yes, it's not very good for it to do this all the time. If you have the option of removing the battery once it's charged, it would be best to do so.

Tibuda
June 25th, 2011, 05:02 PM
Yes, but you should remove your battery.

chinmaya_n
June 25th, 2011, 05:12 PM
Unfortunately.. my battery can not be removed.. My laptop design is in such a way... ( it is inside and screwed )
:-(

haqking
June 25th, 2011, 05:18 PM
i would say that having a battery fully charged and the laptop plugged in is not harmful, because as soon as the charge level reaches 100% the battery stops receiving charging energy and this energy is bypassed directly to the power supply system of the laptop.

however if you are experiencing heat issues that may be transferred to the battery unit then yes remove it.

the unplug thing usually refers to nicad batteries and not the lithium ones of today which dont suffer from memory effect

I have had the same battery in my Thinkpad for 3 years and use it on battery power probably for an hour or so a year if that as it is always plugged into A/C and the battery still holds the same charge

guess it depends on the machine, certainly wont do it any harm to remove it if you can though.

Bart_D
June 25th, 2011, 05:18 PM
Yes, it's not very good for it to do this all the time.

Why? What's the reason?

keithpeter
June 25th, 2011, 05:51 PM
Hello All

http://batteryuniversity.com/

Someone usually posts a link to this excellent site eventually.

I prefer to use recycled/reconditioned/old electronics where possible. I've been using a Thinkpad T42 and a T60 both bought second hand from ebay and both with their original batteries. In both cases I'm seeing close to specified battery life. One is 6 years old, the other 4 years old.

I'm assuming that if your device has a fixed battery, the manufacturer has included charge monitoring circuits that will prevent the battery from overcharging. I'd suggest finding a support forum dedicated to your device and asking there.

Paqman
June 25th, 2011, 05:57 PM
Why? What's the reason?

In a perfect world, a rechargeable battery could simply be charged and discharged as many times as you like, for as long as you like. In reality the chemical changes that take place aren't perfectly reversible, and batteries do get tired with use. There's often a trade off between charging a battery in a way that promotes long life and high stored energy, with many chargers opting for the second (since most consumer electronics are designed for relatively short lives anyway)

Li-ion batteries are much more forgiving than ni-cads, but they aren't perfect.

chinmaya_n: If you can't remove the battery don't worry about it too much. I plug my netbook into the wall if I'm using it in one spot for a long time too.

chinmaya_n
June 26th, 2011, 04:21 PM
@haqking: Ya that is what i'm also guessing :-)
@keithpeter: Ohk, I'll confirm with those forum people.
@Paqman: ya I too work a bit long :)

ThankU all

Note: By the way my laptop is "Dell Vostro V130"

Artemis3
June 26th, 2011, 08:03 PM
Li-ion batteries are much more forgiving than ni-cads, but they aren't perfect.
Li-ions go bad with age, use them or lose them, they don't last longer for using them less...

forrestcupp
June 26th, 2011, 08:57 PM
the unplug thing usually refers to nicad batteries and not the lithium ones of today which dont suffer from memory effect
I agree with this. The new batteries don't have nearly the problem as the old nickel cadmium ones. I almost always have my laptop plugged in, and when I have it unplugged, I can still get the same 3-4 hours out of the battery that I always could.


Li-ions go bad with age, use them or lose them, they don't last longer for using them less...But they also don't go bad quicker from leaving them plugged in more. In my experience, you can usually do what you want and you'll be ok.

Lucradia
June 26th, 2011, 10:48 PM
Yes, it's not very good for it to do this all the time. If you have the option of removing the battery once it's charged, it would be best to do so.

Yeah, now that I have been using my AC power on full for hours on end (8+hours a day for over two+ weeks) with my ASUS EEEPC 1015PE, the 6 hour battery can now hold only 95% Charge max. (Fedora says 95% Charged, 0:00 until full.)

user1397
June 27th, 2011, 03:27 AM
i keep my laptop running on solely AC power like 95% of the time, I try to use my battery sparingly in the belief that doing so will prolong its life (although I am not sure how much it can be affected by being charged all the time, I don't want to risk it)

chinmaya_n
June 27th, 2011, 06:08 AM
I agree with this. The new batteries don't have nearly the problem as the old nickel cadmium ones. I almost always have my laptop plugged in, and when I have it unplugged, I can still get the same 3-4 hours out of the battery that I always could.Cheers ! :P

i keep my laptop running on solely AC power like 95% of the time, I try to use my battery sparingly in the belief that doing so will prolong its life (although I am not sure how much it can be affected by being charged all the time, I don't want to risk it)Same with me...

the 6 hour battery can now hold only 95% Charge max. (Fedora says 95% Charged, 0:00 until full.):confused: Are you sure it is b'se of that reason... I request you to confirm with the Asus forums...

Lucradia
June 27th, 2011, 12:14 PM
:confused: Are you sure it is b'se of that reason... I request you to confirm with the Asus forums...

Just a few days ago, it was saying 100% Charged; 0:00 until full for the weeks prior to this past week.

I don't remember my ASUS Forum account, and I'd rather not re-join.

chinmaya_n
June 27th, 2011, 08:17 PM
Just a few days ago, it was saying 100% Charged; 0:00 until full for the weeks prior to this past week.

I don't remember my ASUS Forum account, and I'd rather not re-join.

:(:( I'll confirm with Dell forums

Lucradia
June 27th, 2011, 09:55 PM
:(:( I'll confirm with Dell forums

Guess what, now it's back to saying 100% 0:00 until charged. I think Fedora is playing tricks on me. (I need Fedora though, as Ubuntu cannot obtain the IP Address for library networks; but Fedora can.)

Pogeymanz
June 28th, 2011, 01:13 AM
Actually, I've heard that the reason you shouldn't leave the battery in after it's charged is not the memory effect, but heat. The battery is still being warmed by your laptop, which is not good for it.

My question is, is it bad to just remove a battery while the computer is running? I've done it a lot and it just now occurred to me that maybe you aren't supposed to do that...

KiwiNZ
June 28th, 2011, 02:15 AM
If you have your laptop on mains for long periods you should charge the battery and remove it, store it in a cool dry location. Just ensure that your power supply is secure to avoid disconnecting and improper shut down of your Laptop.

nzjethro
June 28th, 2011, 04:40 AM
I had my laptop (HP dv5) plugged in for long periods of time, and I'm fairly sure that cooked the battery. I got down to about 3 minutes of battery life before it'd shut down. Mind you, HP dv5s have pretty shocking battery life to begin with. :P

chinmaya_n
June 28th, 2011, 05:27 AM
Guess what, now it's back to saying 100% 0:00 until charged. I think Fedora is playing tricks on me. (I need Fedora though, as Ubuntu cannot obtain the IP Address for library networks; but Fedora can.)
I loved it !! :cool:

The battery is still being warmed by your laptop, which is not good for it. Pleasing idea... May be :(


My question is, is it bad to just remove a battery while the computer is running? I've done it a lot and it just now occurred to me that maybe you aren't supposed to do that...If the electricity is bypassed in your laptop after fully charged, I guess it would not cause any problem.

If you have your laptop on mains for long periods you should charge the battery and remove it, store it in a cool dry location. Just ensure that your power supply is secure to avoid disconnecting and improper shut down of your Laptop.Not possible in my case :-k

I had my laptop (HP dv5) plugged in for long periods of time, and I'm fairly sure that cooked the battery. I got down to about 3 minutes of battery life before it'd shut down. Mind you, HP dv5s have pretty shocking battery life to begin with. :P
My friend has HP dv5 Laptop, Not sure if there are any varients. But it gets toomuch headed up while charging.. ( It would definitely cook your bettey ) Dont know if it is same in your case also...

pjd99
June 28th, 2011, 06:01 AM
If you have your laptop on mains for long periods you should charge the battery and remove it, store it in a cool dry location. Just ensure that your power supply is secure to avoid disconnecting and improper shut down of your Laptop.

Actually you shouldn't charge it.

If you are looking to get the most life out of a Li-ion battery, discharge to 40% then stick it in the freezer. Ambient temperature will reduce the capacity of a Li-ion over time.
100% charge @ 25 degrees C, a Li-ion battery will lose about 20% of its design capacity per year.
40% charge @ 25 degrees C, it will only lose about 4%.

Source: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries


But for most purposes (and for the OP's case) it wont really matter. I've got a Dell Vostro 1710 (battery is removable). It's 2.5 years old, and I generally run it on the AC adapter. I keep the battery plugged in for when a power outage occurs, or for when I want to move it while it's on. Because of this, the battery when fully charged is now only 57% of its original capacity. If you want to run it on battery after 3-4 years, get a replacement battery.

Battery info - check capacity and cycle count:

cat /proc/acpi/battery/BAT1/info

nzjethro
June 28th, 2011, 06:03 AM
My friend has HP dv5 Laptop, Not sure if there are any varients. But it gets toomuch headed up while charging.. ( It would definitely cook your bettey ) Dont know if it is same in your case also...

Yup, heating up is another issue. I cleaned out the fan a month or so ago, which brought the temperature down a bit, but it's still pretty darn hot.