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Extending the life of my laptop's battery

by Lee Koo (ADMIN) CNET staff/forum admin / March 13, 2009 6:40 AM PDT

Hello, I have a HP laptop that about 1.5-years-old and its battery is in such a pathetic state. When I pull the plug on it the laptop, it completely dies off (shuts down). It's as if my laptop is on a respirator (the battery) and it can't breathe on its own. Since it was getting highly frustrating that my original battery would not hold any charge whatsoever, I resolved to get a 12-cell lithium ion battery. Now, I am more concerned about how I can use my battery more efficiently. What should I do to preserve the condition of my new battery so it can work longer? It is expensive to replace a battery every year. Please let me know what all I can do to extend the life of my battery. Should I be plugged in all time while I'm using my laptop or should I charge and discharge it? I will greatly appreciate your recommendations. Thank you!

Submitted by: Raji K.

Here are some featured member answers to get you started. Please also check out what other members have contributed to this member's question.

Getting maximum life from a laptop battery --Submitted by Watzman

Here's what you should do... --Submitted by LMF5000

Extending the life of my laptop's battery --Submitted by Aparicio Mart
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I don't /know/ the answer, but...
by William Sommerwerck / March 13, 2009 11:00 AM PDT

As far as I know, lithium-ion cells don't have a memory, and are not bothered by frequent recharging. Therefore, I would plug the notebook in whenever I was near an outlet.

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Battery Removal
by Barking Mad / March 21, 2009 10:42 AM PDT

On a Toshiba laptop I thought that the AC power was run through the battery. That is, the external power input routes the AC through the battery to the computer. How do I access AC with the battery out?

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the answer to your question is no
by Kegtapper / March 22, 2009 12:08 AM PDT
In reply to: Battery Removal

Batteries in most modern laptops are not 'in-line', that would make them essentially a fuse. There are switches (MOSFETS) that control the flow of power. When there is no battery in the unit a small mosfet switch directs the current to the system. When there is a battery in, another switch determines if there is enough charge in the battery, If yes, it sends to system, if no- it sends to the charge circuit.

Often the charge circuit is lower voltage than the actual AC adapter. example: a 19.2v power supply may only put 14v on the charge circuit.

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Laptop batteries
by GFW / March 13, 2009 11:05 AM PDT

It is my understanding that Lithium cells work best if kept fully charged. Each deep discharge is hard on them, whereas a NiCad cell is the opposite - with them it is best to let the battery run down fairly low before charging.

Now that you have gone lithium, I would try to never let the charge get below the halfway point except when necessary.

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battery life
by sedicn / April 2, 2009 6:53 PM PDT
In reply to: Laptop batteries
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Plug it in
by DSE319 / March 13, 2009 11:15 AM PDT

When ever convenient, plug it in. You have somewhere between 300 to 500 discharges of most Lithium Ion batteries.

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Laptop Batteries
by darrenforster99 / March 13, 2009 11:36 AM PDT

Hi Raji,

Unfortunatly with modern lithium-ion batteries there is very little that can be done to prolong the life of the battery.

Years ago with ni-cad and ni-mh batteries the solution was to fully charge them at first, and then fully discharge them every time

There are however a few things that can help a bit,

firstly when buying a new laptop battery try and find one that has been stored in a cold warehouse properly. The Duracell batteries tend to state on them that they've been stored in a cold warehouse.

With Li-ion batteries the minute they are made they start to degrade, there is safety contacts inside the battery that start dissolving as soon as the battery is made, once this reaches a critical level the battery is designed to refuse charge, accepting charge could be very dangerous at this point and cause the battery to explode, hence why the safety mechanism steps in and refuses charge.

By storing the battery in a cold warehouse it prevents the battery from degrading as much until you receive the battery. Even though it prevents it, it doesn't fully stop the degrading.

The next thing is try and see if you can get hold of a battery that has only recently been made, check the batch number on the battery to see. The newer the battery the better, even if it's been kept in a cold warehouse the battery will still have started to degrade.

There is one final solution, it is entirely at your own risk, I have heard of some success stories, although some people have also said it's not worth doing it, and others have reported that it has damaged the battery as water has formed inside. This is to store the battery when not in use in the freezer. As I can tell this is similar to the way the manufacturers store the batteries in their warehouses to prevent them degrading. However storing thousands of batteries in frozen warehouse is totally different to storing one in a home freezer. I would probably go for the fact that this method isn't worth it.

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Batteries have a charge/discharge life.
by saadhusain / March 13, 2009 11:40 AM PDT

The best way is to use AC with the battery removed unless you really need it.

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extending your battery life
by tongkianshin / March 13, 2009 12:08 PM PDT

Hi, i must said that i not an expert , but only to let other know what i do to extend my laptop battery life.

I bought an Asus laptop 5 years ago, the battery can still hold charge and can last for around 1 hour time. it almost same as a the time i bought it (remember it's 5 years ago).

What i do is always take out battery when using AC adaptor, tis way the battery won't charge every time i use it. Every battery got it own charge circle, some 100 times, some may be less or more.

Charge your battery only when it run out or when you know you need to use it outdoor next day. Some laptop provide a program to recalibrate your battery, use it at least once every 6 months (Asus provide it under bios setting, i can't find any program to do that for dell laptop).

Hope this can help. Thank you.

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the best method ever i thought forRetaining the battery life
by amrinder121345 / March 13, 2009 11:32 PM PDT

The best method to retain the life of battery is always try to use the battery only wen one needs ,,,,, means if u have power supply and go for it n remove the battery minimise the circles of recharging the battery again n again

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response to tongkianshin.
by bobbybabby / March 17, 2009 1:27 PM PDT

I agree with tongkianshin. While using AC power, I remove my battery and keep it out until a day before I need it.Then I re-insert the battery and let it charge overnight. I've been doing this for more than a year, and my battery is still operating like new.

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extending your battery life
by POP61 / March 20, 2009 3:53 PM PDT

I do exactly the same with my 4 years old Toshiba Satellite and my battery is fine.

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use ac adapter
by patdegnan / September 23, 2009 1:22 PM PDT

Thanks for your kind information. I agree with you, and always use ac adapter in the home.
but how to store my laptop battery?

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make your batteries last
by vid1900 / March 13, 2009 12:21 PM PDT

NEVER keep the battery in the laptop, always fully charged.

Unless you need to be on battery power, let the battery drain to 30% power and store it out of the laptop.

Only charge it up 100% when you are going out and actually need to run on battery power.

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Getting maximum life from a laptop battery
by Watzman / March 13, 2009 12:25 PM PDT

Laptop Lithium Ion batteries are very expensive (quite a few of them are over (WAY over, in a few cases) $200). They CAN last 10 years (in fact I have some 1995 Toshiba batteries that are still nearly as good as new), but they can also be destroyed in less than 6 months. As an engineer who has both worked for laptop manufacturers and who services laptops, here is what I can tell you:

The most important rule of getting good life from a battery is this: If you are not traveling, if you are stationary and are going to be plugged into a wall outlet for a day or two or perhaps essentially all of the time, take the battery out of the computer entirely and store it in a cool, dry place (some people will recommend a refrigerator, but that is not necessary, will probably not make a difference that you will really notice, and can damage the battery if the temperature gets too cold (freezing)).

It's not clear why this is necessary, and on some models it may not be necessary (your post, however, suggests that it IS necessary on your model). However, there is OVERWHELMING annecdotal evidence that this is the single most important thing that you can do to have your battery last years and years, for the times when you really do need it, when you are traveling and want to use the laptop in a car, on a plane or in various transient locations.

The two likely culprits here are overcharging and heat.

While in theory the charging circuits should shut down [COMPLETELY] when the battery is fully charged, there is evidence that in many laptops they don't; they continue charging the battery continuously , albeit in a "trickle charge" mode. This may sound good, but in practice it can damage the battery.

Secondly, it is a well known fact that Lithium Ion batteries are terribly sensitive to permanent damage by exposure to elevated temperatures (and "elevated" in this case starts in the range of around or just over 100 degrees F (about 40C)).

With regard to elevated temperatures, storage in a turned-on laptop is problematic for two reasons. First, there is a lot of heat in the laptop (from the various laptop components: CPU, hard drive, power supply, etc.), and the battery is, to varying degrees, exposed to this heat (note, however, that battery exposure to this heat varies by model depending on the thermal design and placement of the battery relative to other heat generating components). Secondly, if the charging circuits do not shut down COMPLETELY, charging itself (even "trickle charging") generates heat from directly within the battery itself which is harmful over time.

Now, a few more comments:

First, it's probably not a good idea to remove the battery while you are staying in a hotel for a few days, even if you won't need it. The risk of forgetting the battery in the hotel room when you check out is significant (you can mitigate this by leaving the battery in your laptop bag, but ask anyone who uses PC Cards about "lost dongle cables").

Second, notwithstanding the general advice to remove a battery that is not needed and not being used, the battery needs to be exercised 2 to 4 times a year. So, once in a while, put it back in the laptop, draw it down to about 25% (NO LOWER!!) and then charge it back up to about 60% (or 100% and then back down to 60%; Lithium batteries store better with a less than full charge although in my personal experience I have not found the difference to really matter very much).

Third, if your laptop is really used as a compact desktop at home or at work and in fact doesn't travel much, removing the battery robs you of it's function as a "UPS". Solution: Buy a [real] UPS. For a laptop, you only need a small one (300 to 350VA), these can be found for $40 or less (sometimes even "free after rebate"), and a UPS is a lot cheaper than using a $200+ lithium battery as a UPS but destroying it over a period of 6 to 24 months in the process.

Also note that Lithium batteries have a finite and limited life in terms of the number of charge/discharge cycles, calendar time not withstanding. Although this varies by battery model, it's in the low-to-mid hundreds (say 300 to 600 cycles as a typical range). If you really are using your battery while traveling, charging and discharging it on a daily basis, this fact will "get you" no matter what you do. But, more commonly, people find that they have destroyed their battery without ever really using it, by leaving it in the laptop while the laptop was plugged in continuously. And we have already covered the solution to that problem.

One last comment, given the price of laptop batteries, it's worth noting that SOME extended warranties cover the batteries. If you are really going to be using the battery heavily (see the previous paragraph), this may be worth taking into consideration when the colored shirt guy at Buy More offers you an extended warranty at the time of the laptop purchase. Find out (IN WRITING!!) if the battery is covered, and if your use pattern is such that you will probably be going through more than the initial battery over the course of the extended warranty, maybe you are in one of those situations in which an extended warranty really does make sense.

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by NEM0.N00NE / March 20, 2009 1:14 PM PDT

Very comprehensive & informative post. but for us totally non-tech types, what do you mean by "UPS" function?

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by brazilboy87 / March 20, 2009 2:08 PM PDT
In reply to: Battery

UPS means, uninterruptible power supply.

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Li-ion batteries and ups
by kdsmithjr / March 22, 2009 1:22 AM PDT
In reply to: Battery

UPS is an abbreviation. It's not important to know what the abbreviation means, but what is important to know is that it stands for battery power backup for computers. Power backup should not be confused with file backup; power backup simply means that the UPS battery-based power system kicks in immediately when it senses a power failure (AC power) to your machine.

Laptops what have batteries in them are a kind of UPS enhanced system since the battery in the machine is automatically set up to power the machine, without interruption whenever you disconnect your laptop from the wall socket. Thought it might work the same way, with laptops the fact that the battery 'kicks in' upon disconnection from AC power is really more an artifact of they way the system is set up versus battery based power, i.e. UBS, kicking in as an emergency power system to prevent possible disaster from your maching 'going down' because of a power failure.

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ALWAYS remove battery from the back when laptop i plugged in
by kurkosdr / March 22, 2009 6:30 PM PDT
In reply to: Battery
The trick to have a laptop battery that doesn't die once a year is the following:

Always remove your laptop's battery from the back of the laptop when your laptop is plugged in and running.

This prevents the battery from:
1) Being in a constant charge-decharge situation. Even if your battery is charged 100%, the battey is still on line. Basically, the battery is always online. So, when you turn on your laptop, and the laptop is plugged in, the battery enters a constant charge de-charge situation, as electricity from the AC adapter goes through the battery first before reaching the mainboard. And this is bad for the battery's life. Remove battery from the battery bay to keep it offline. Simple as that
2) Overheating. Laptops draw more energy when plugged in and as a result, produce more heat. Batteries can't last for long when exposed to this heat. Remove battery from the bay to keep it cool while you will be working for long yours with electricity from the grid. Simple again.

The above advice may sound stupid, but believe me, it works!! I have a 3 years old hp compaq nx9420 notebook.
I m using it to play games (both when plugged in and when running on battery), edit video, compile code, often for 10 hours a day!! And I haven't practically lost any battery time (only 10 minutes, but this is kind of negligible since it's 3 years old). The reason: I never run it with both the battery and the plug in.

Instead, my friend's hp compaq is also 3 years old and is used only for net serfing, but he didn't know he should remove the battery when plugged in, and now it can barely stand for 20 minutes out of plug

There are other people on the net that will tell you reducing the amount of energy your laptop is consuming when running on batteries, by avoiding demanding tasks (ex games/video) and reducing screen backlight/brightness. will help battery last longer, but it is not going to have any real effect. The only advice having any real impact on the battery's life. Period.

PS: The only side-effect of the above tip is that you can't use the battery as a UPS in case electricity from the grid is cut off, but let me tell you the battery won't prevent you from voltage peaks (the ones that do the real damage) anyway so go and purchase yourself a UPS and stop using the laptop's battery as one.
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good advice but really inconvenient
by jaflady / March 22, 2009 10:18 PM PDT

If using a laptop on a daily basis - taking back and forth to work etc as I do then removing battery, putting in, taking out, plugging in and out etc. would be a very tiresome chore. Though I know it is what one should do - that would mean putting it back and forth several times nearly every day. It is really not practical. What we need obviously is much better battery tech. That appears to be the major stumbling block to truly efficient portable use. Until that is solved - most of us will have batteries that stop holding a good charge after a year or so.

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by newmodel15 / March 22, 2009 8:09 PM PDT
In reply to: Battery

Interruptible Power Supply - essentially a battery back-up to a mains supply.

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by ia3d / March 22, 2009 8:55 PM PDT
In reply to: Battery

To me, UPS stands for United Parcel Service. In this case, however, I think the author meant Universal Power Supply. Just a guess, though.

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What is a UPS
by ahmaduhhs / March 22, 2009 11:15 PM PDT
In reply to: Battery

a UPS(uninterrupted power supply) instantly switches your computer to emergency battery backup power and allows you to work through brief power outages or to shut down your system in the event of an extended outage.

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Definition of "UPS".
by seanmusic / March 23, 2009 1:46 PM PDT
In reply to: Battery

UPS stands for Uninterrupted Power Supply. It kicks in for a time (until its own power source runs down)in case your AC power goes off unexpectedly; allowing you the time to save your work, shut down properly, and/or any other task that would otherwise reek havoc on your computer, if the power were to go off suddenly.

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What is UPS?
by galeung / March 20, 2009 2:58 PM PDT

I enjoyed reading yoru article on getting maximum life from a Lithium laptop battery. But what is UPS that you advised us to buy?

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Hi to all & thanks for this good subject, usefull & needed
by pringo / March 21, 2009 7:44 AM PDT
In reply to: What is UPS?

UPS works as a battery, it stores electricity. As mentioned by our friend "brazilboy87" it will supply power with no interruption, so even when the electricity goes off, you can still get power from UPS though for a short/limited period!

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UPS for home computer work station and for home theater
by urhett / April 26, 2009 2:06 PM PDT

I'm shopping for three new UPS. I'm familiar with APC brand and have been told that it's the only one to consider. Considering consistent performance and cost what do you think about APC and are there any other companies that you'd recommend? Thanks for your thoughts.

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getting maximum life for a laptop battery
by kerbro / March 20, 2009 3:05 PM PDT

in you response to the query you responded by stating:"The most important rule of getting good life from a battery is this: If you are not traveling, if you are stationary and are going to be plugged into a wall outlet for a day or two or perhaps essentially all of the time, take the battery out of the computer entirely." My problem is this,I have a Toshiba Satellite p25 laptop when I tried to run computer without the old battery that was not holding a charge after 4 years, the machine would not operate. It still will not operate without the battery inside. Additionally my power meter is still showing the original battery which has been replaced by a new one monthes ago, I called toshiba and then told me to download 2006 BIOS updates, which I did and burned to cd which burned using ISO. I followed instructionsd and rebooted with the cd. Everything was going smoothly and then the computer shut off and would not come back on. I played around until I got it back on. After a number of tries I called Toshiba and the Tech tried to download the bios directly to the computer which did not work. I now have new battery which is operating under the parameters of the old one I can only use battery power for a few minutes (like when I have to go across the room to my printer)before it cuts off. The Toshiba guy said that I should go to authorized repair shop,the first guy said he was going to charge $50 just for me walking through the door. I realize this has been a lengthy posting (even more painfull for me because I can't type)but I would appreciate some input,advice whatever.

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Battery life
by sampler111 / March 20, 2009 5:38 PM PDT

Hi what you say ounds good but just a quick point i would like to make and this comes from an Electronics Technician who states that if you do as you have said in taking the battery out of the Laptop this is not good asaccording to him the Battery smoothes out the power going into the Laptop and if for some reason you get a spike in the power and the battery is not in the you rish the chance of blowing the Screen Inverter.
So just a quick note of caution for anyone thinking of doing thisi would check this out first.

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Change your tech
by Kegtapper / March 22, 2009 1:07 AM PDT
In reply to: Battery life

He is giving you technobabble. The battery does nothing to smooth out current or ripples in AC. That is a job for filters, chokes and MOV's.

On laptops that do not run when battery is removed-
The problem is usually a DC Jack needing replacement. The jack has 3 legs, one for POS, the other for NEG when plugged in, and NEG when not plugged in. Often cold solder joint prevents one negative side from pulling up electronics from the Negative side. So no power.

For systems that do not use the 3 pole connection, they use chips to control current flow.

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