Leaving laptop plugged in?

[pookguy88]

is it ok to leave a laptop plugged into the wall (AC power) for long periods at a time?

cause i mean i usually use my laptop as a desktop replacement and, as such, is plugged into the wall most of time. does this cause harm to the battery/laptop? like is it good once in awhile to use the battery charge? also i'm wondering because when i have the laptop plugged into the wall the light on the laptop signifying AC power is lit all the time, will it wear out?

 

[KK]

Originally posted by: pookguy88
is it ok to leave a laptop plugged into the wall (AC power) for long periods at a time?

cause i mean i usually use my laptop as a desktop replacement and, as such, is plugged into the wall most of time. does this cause harm to the battery/laptop? like is it good once in awhile to use the battery charge? also i'm wondering because when i have the laptop plugged into the wall the light on the laptop signifying AC power is lit all the time, will it wear out?

Will the light wear out? I don't think you'd have to worry bout that. I have a laptop at home that I leave on about 99% of the time and connected to AC about 90% of the time. it hasn't hurt mine yet.

 

[vegetation]

It's fine but ensure the drive powers off after so much time sitting idle. Also, you might want to remove the battery, depending on your model, as heat will kill a battery off early and some laptops can get awfully hot underneath.

 

[icefist]

if you are not using your battery at all, remove it!

 

[MercenaryForHire]

Originally posted by: icefist
if you are not using your battery at all, remove it!

Correct. Overcharging a battery will shorten its life. Once it's full, either remove it from the laptop or unplug the unit from the wall.

- M4H

 

[sciencewhiz]

Originally posted by: MercenaryForHire
Overcharging a battery will shorten its life. Once it's full, either remove it from the laptop or unplug the unit from the wall.

That's true, but modern laptops don't overcharge batteries.

 

[fbrdphreak]

To my knowledge (and if anyone knows otherwise and can prove it), when a battery becomes 'full' or close to full (i.e. 97%+); the battery gets what is called a "trickle charge." This produces a very small current to ensure that the battery just not (A) just drain if NO current is let through and (B) that the battery does not overcharge if ALL current is let through. However, I do believe you still do not want to leave the batt charging 24/7. From my experience with people who have left their batt's in 24/7, batt life is greatly diminished if they have been leaving the battery in for long periods of time. I did a little Google-ing on the subject a while ago and all I could really find was saying that if you are going to leave a battery "discharging" (i.e. not being charged), that you should leave it at around 40-50% of its full capacity (like if it is just sitting in a drawer). Why this is, I do not know. Anyone have a more definitive answer?

 

[imported_Krypto]

I did the same thing with my 2 laptops. I charged the battery full, then every once and a while I put the batteries back in run them down some and then recharge them fully and take them out. No problems so far and I see no difference in battery time.

 

[pookguy88]

anyone know if a Thinkpad A21P can even be run without a battery in it?

 

[sciencewhiz]

Originally posted by: pookguy88
anyone know if a Thinkpad A21P can even be run without a battery in it?

My A21m could

 

[imported_Krypto]

Personally, I have never heard of a laptop not booting if it did not detect a battery. That's just me, are there laptops out there that do that?

 

[dnuggett]

Originally posted by: MercenaryForHire

Originally posted by: icefist
if you are not using your battery at all, remove it!

Correct. Overcharging a battery will shorten its life. Once it's full, either remove it from the laptop or unplug the unit from the wall.

- M4H

Actually this is a commonly misunderstood. If we are talking a Lithium Ion battery and a newer laptop (last 2-3 years) there is no need to remove the batttery. They do not overcharge.

 

[eriqesque]

Modern day notebooks with a Li-ion battery do not trickle charge.
They charge to a 100% and the charging cicuit in the battery shuts off.
So there is no trickle charge.
Now if you are using the machine and it gets hot this will shorten your battery life over time.
The worst thing for the battery is unfortunately heat.

 

[MercenaryForHire]

Originally posted by: dnuggett

Originally posted by: MercenaryForHire

Originally posted by: icefist
if you are not using your battery at all, remove it!

Correct. Overcharging a battery will shorten its life. Once it's full, either remove it from the laptop or unplug the unit from the wall.

- M4H

Actually this is a commonly misunderstood. If we are talking a Lithium Ion battery and a newer laptop (last 2-3 years) there is no need to remove the batttery. They do not overcharge.

Well, he didn't say the age of the laptop, now did he?

There must be a lot of old-tech sitting in new laptops then, because I still see pooched batteries from fresh laptops.

- M4H

 

[dnuggett]

Well, he didn't say the age of the laptop, now did he?

Call me crazy, but I'm guessing if he's using it as a desktop replacement it isn't that old.

Cmon' its okay...admit you didn't know it.

There must be a lot of old-tech sitting in new laptops then, because I still see pooched batteries from fresh laptops.

No, thats called bad manufacturing or quality control.

 

[fbrdphreak]

Could we also address the whole issue of proper battery maintenace? According to the documentation w/my T42, you are supposed to do a complete discharge of the battery (i.e. let laptop die) once per month and then do a deep charge (i.e. charge overnight) to maintain batt life. However I have also heard that doing any complete discharge of a Li-On battery will reduce its capacity. I've had my T42 since August and unfortunately a couple times in one week the laptop died while running on battery. In the past couple weeks, I've noticed a decreased battery life and the IBM battery utility indicates the "Full Charge Capacity" to be 43.87Wh whereas the "Design Capacity" is listed as 47.52Wh. This is a 6-cell battery btw. Is that what reduced the capacity or should I expect that over two months?

 

[MercenaryForHire]

Originally posted by: dnuggett

Well, he didn't say the age of the laptop, now did he?

Call me crazy, but I'm guessing if he's using it as a desktop replacement it isn't that old.

Cmon' its okay...admit you didn't know it.

There must be a lot of old-tech sitting in new laptops then, because I still see pooched batteries from fresh laptops.

No, thats called bad manufacturing or quality control.

/shrugs

Old habits die hard I guess.

- M4H

 

[imported_Woody]

My last notebook I purchased about 4.5 years ago was a Macintosh Powerbook G3. The battery began showing signs of shorter life after a couple years and after about three years it would only charge to about 40-50% of it's original capacity. After four years it was barely able to hold any charge. I used this laptop almost everday and kept it plugged in almost all the time while the computer slept rather than shut down. This meant the battery was constantly getting "topped off." The Mac had a really cool design that allowed you to just pop the battery in and out while the computer was running and without tipping it on it's side. In retrospect I should have done this more. I have since given this laptop to my daughter and purchased a new "high capacity" replacement battery from a third party which holds significantly more charge than the orignial ever did. I encourage her to keep the system unplugged when not using it.

I use my new eMachines laptop just as frequently but removing the battery is less convenient than on the Macintosh. Since I often use the system as a portable system running on batteries I like to keep it fully charged at all times. When not using the system I hybernate rather than sleep and then uplug it. Typically I just throw the switch on the power strip instead of physically unplugging it. I think this will help my battery life but for the most part I just accept that I may need to purchase a new battery in a couple years if I'm keeping this laptop.

 

[piasabird]

You could just read the manual.

Duh! Duh!

 

[Mermaidman]

I leave the battery in in case of a power outage.

 

[wjgollatz]

WHat is the source that lithium ion batteries in laptops do not trickle charge? Rolled and prismatic cells (cell phones and lap tops) have always been trickle charged in my experience - and my experience with them - which did end only 3 years ago researching lithium ion battery use for crusie missiles, AA missiles, satellites, cell phones, NASA and other secret military projects - trickle charging was used. In fact, trickle charging the li-ion cells gave them longer life when measured by power given to full discharges. The trickle charge is used because if one trying to charge the cell at full power, ions "block" the pathway for the electrons, using a smaller voltage the pathway is no blocked by opposing electrons - helps keep the cell at the highest state of charge - especially given that li-ion cells almost max out on voltage at about 85-90% of full charge - and one needs to trickle charge the remaining 10-15% - or one just wastes power trying to charge the cell.

 

[sciencewhiz]

Originally posted by: wjgollatz
WHat is the source that lithium ion batteries in laptops do not trickle charge?

eriqesque's post was slightly misleading when he said that laptops don't trickle charge. He was responding to fbrdphreak who stated that laptop's continuously trickle charge to keep the battery topped off. That isn't true in modern laptops (made in the last 2-3 years). Modern laptops charge to 85 - 90%, as you stated, then they trickle charge to 100%, then the shut off the charger. After the batteries self discharge a certain amount (5% on both my IBM laptops), they trickle charge to 100%. Thus, they do trickle charge, but will not overcharge the battery by trickle charging.

There are a bunch of factors that kill LI-Ion batteries. Heat, usage, overcharging, and time are the big ones. Even if you never use a LI-Ion battery, it will only last 3 or so years. That's the effect that Woody saw on his powerbook.

 

[jamesbond007]

Originally posted by: Mermaidman
I leave the battery in in case of a power outage.

I do this too. I have a Toshiba laptop currently and the laptop has been on 99% of the time in the past year I've owned it. Also, the battery has been in as well, but I have yet to see any kind of decrease in life.

I guess we could say that YMMV in terms of leaving the battery in while the laptop is on for extended periods of time. (ie: months/years)

 

[imported_Woody]

If they have a shelf life of only three years or so then all of this is moot.

Come to think of it that makes sense. I had a cell phone I kept for about three years. No problems ever with the battery which i charged religiously every night. After about three and a half years it just wouldn't hold a charge anymore. It began to die very quickly. Cheaper to get a new phone.

 

[MDE]

I leave mine on and plugged in all the time, haven't had a problem yet.