how to properly charge battery?

[lruggier]

Is it harmful to my laptop if I charge it up to 100% when it is just at 75% battery? Or should I wait for it to die until I charge it?

Since I have been charging it for the past month before it died I feel like the battery is having trouble holding charge more than 3 hours when it usually can hold up to 4-5 hours. Have I ruined my battery? All the power settings are on the same settings as before, which are the lowest ones.

[Detection]

Probably fine if its a newish battery, just remember to fully discharge it and fully recharge it like once a month or so

[lruggier]

Yeah it is new, I got it in January 2011. This just worries me because I got the computer because of the great battery life and I want it to be able to survive a 3 hour class and still have more battery like it did last year and last semester.

[Detection]

Its over a year old, its probably not going to hold the same charge as it did new.

Give it a few 100%>0%>100% cycles (Charge it with the laptop powered off overnight for a good full charge)

[lruggier]

Ok I will do that, but the reason I am concerned is because this just happened within the past month when I started to charge it when it wasnt even close to dead yet.

Is it bad to leave in the charger overnight while the computer is off and charging it? Or is that considered overcharging it like when it is charging when the computer is on after 100%

[Jose_49]

Ok I will do that, but the reason I am concerned is because this just happened within the past month when I started to charge it when it wasnt even close to dead yet.

Is it bad to leave in the charger overnight while the computer is off and charging it? Or is that considered overcharging it like when it is charging when the computer is on after 100%

Battery stop charging after it hits 100%. From personal experience it doesn't harm the battery. I have left mine plugged in for several days (many many many times) throughout 3 years. Eventually it hit its end of the charging cycle and I needed to replace it. (I can still get 50 mins from it. 6 cells battery BTW)

What battery suppliers suggest is, as Detection said, to fully charge and discharge your battery once in a while, so it can get back to its full charge.

Also if your battery is not from the original supplier its time will vary (Sometimes more, sometimes less). I mean if you have a dell laptop and didn't purchase it from an authorized Dell distributor, don't expect too much of the third party battery, since you'll get it at 1/5 th of the price.

Edit: On a side note: What does kill it pretty fast is the constant plug in/out that people tend to do. You see, batteries have around 500 - 700 power charging cycles. At the moment you disconnect the PC and reconnect it, one Power Cycle is lost (One of those 500-700) because the battery starts charging again. So, if you keep constantly disconnecting and reconnecting the PC you'll just cut the life span of the battery to less than it should. That's why people complain a lot about very short battery usages (Except for HP laptops, they are crap) and they don't know that the main reason is that constant recharging cycle they impose to the machine.

Sorry if being too technical....

[lruggier]

Ok, but i thought that one cycle was letting your computer completely die and shut down

[Jose_49]

Ok, but i thought that one cycle was letting your computer completely die and shut down

Nope. No need to worry about that. Continue using your PC normally, and if you disconnect it, try using the battery's life the most you can. But if you plan on an overnight download or just want to let it plugged in again, do it, it won't harm it at all.

[Detection]

The main reason for giving it a full discharge and recharge cycle with newer batteries is not really for the batteries sake, its for the sensors, new batteries don't have the memory effect like the old ones did, where not using the full 100% over a long time would kill that part of the cell

If you continuously (months and months) charge your battery at 75% the sensors will calibrate wrongly and begin to think 75% is close to dead

Giving it the full cycle once in a while (And also the recommended 8 hour charge when new) is to correctly calibrate the sensors into knowing what 0% is and what 100% is

[lruggier]

Why do I need to leave it plugged in for 8 hours while its off charging if it only takes about 4 hours to charge? I did that last night except I took it out at 6 hours and it said battery life of 3 hours and 25 minutes instead of 3 hours like it has been saying this past month when I started to charge it improperly by charging it when it wasnt below 20%, and usually 75% or 50% battery was still available.

[Detection]

I already said, its not for the battery, its to calibrate the sensors

And you only need to do that when you first get it, I just suggested leaving it charging overnight to give it a good charge, leaving it powered off just gives less stress on everything for a decent 100-0-100 cycle

[xendrome]

Probably fine if its a newish battery, just remember to fully discharge it and fully recharge it like once a month or so

Pretty sure this is a good way to kill a Li-Ion battery..

[Detection]

Pretty sure this is a good way to kill a Li-Ion battery..

??

Why would you think that ?

I have Li-Ion batteries in laptop and tablet and give them both full cycles every now and then

Most devices won't allow a complete discharge anyway, they will power off around 3% (ish) although Ive seen my dock battery hit 1% many times (infact I think 0% at one time)

[+Warwagon MVC]

Here is a blerb from the coverage of Lithiam Ion batteries on Security now

TOM: Yup. A listener who wished to remain anonymous, did not share a name or location, commented about lithium ion batteries: Steve, following up on discussion of the care and treatment of the lithium ion batteries, HP, for example, says to discharge to 5 percent now and then so that the "smart battery" technology can recalibrate, as you say. But if the calibration is already wrong, wouldn't the 5 percent be impossible to guess? I recently bought a secondhand HP NC4400 with a battery that said it only had 40 minutes left, even after I charged it. So I fully discharged it until it went off and then recharged it, and now it says four hours, 20 minutes, almost like new.

Apple seems to say that it isn't full discharges that cause the trouble, but a deep discharge - for example, the result of a battery left fully discharged. HP says: "Remove the battery from the notebook if the notebook will be plugged into AC power continuously for more than two weeks." So perhaps it's not a good idea to leave laptops always plugged in. Now, this is almost a religious controversy in some ways. But what do you think?

Steve: Well, okay. So I wanted to explain a little bit more about the need to cycle lithium ion. First of all, I don't disagree with any of that. But it needs to be sort of explained a little bit more. And I mentioned - this was just my - I brought the point up myself last week, out of the blue, because I saw a friend who was draining some electronic device of hers, I think it actually was a Kindle that had "I am discharged" on the screen, and it wasn't happy. And I asked her, I said, "So do you just read your Kindle day in, day out, day in, day out until that happens" - and frankly I know that my mom does - "and then you plug it in?" And she said, "Uh, yeah." And I said, "Okay, that's not good. Lithium ion batteries do not like to be run that way. It is much better for them if you keep them charged up."

And so that was the point that I wanted to make, and I generated a bunch of feedback through our mailbag and also on Twitter of people wanting links, people asking me if I was sure and so forth. So relative to this recalibration, the reason it's necessary to do that is the lithium ion batteries do not produce anywhere near a linear decrease in voltage as they discharge. If they did slowly drop down their output voltage as they're losing charge, then it would be easy for the battery management technology to simply measure the voltage on the batteries to determine what percentage of them that they were full.

Instead, lithium ion as it's discharging from a full charge initially drops its voltage by a few tenths of a volt, from 4.2 down to about 4 or 3.9, 3.8. Then it's absolutely or nearly absolutely flat for the bulk of its lifetime. And only at the very end does the voltage then suddenly drop off. Which means that the battery gauges that we have on our laptops, which I love, just handy to be able to look at it and say, okay, you've got about three hours left. I mean, it's much nicer than not having any indication of when the lights are about to go out. So they can't, there's no feedback they can use from the battery itself because the battery is just giving them the same output voltage all the way along, except at the very beginning and at the very end.

So they use timing. And so there's been a lot of human effort that's gone into developing this technology, the idea being that the system monitors the total amount of current being drawn, that it's able to measure moment by moment. And so in software it integrates the instantaneous current drawn from the battery in order to determine how many total amp hours have been taken from it, estimated against its known full size of the battery. So basically it's just - it's knowing when you're running it, and it knows how much current you're pulling it over time. It knows when you plug it in, for how long you plug it in, how much current is put back in.

So it's sitting here looking at this straight line of voltage and just sort of juggling, saying, okay, now we just added 10 percent. Oh, now we took out 17. Oh, now we put in 12. Oh, now we took out 20. Now we put back in 15. And so you can imagine that all of that is better than nothing, but it's a little error prone. You're going to, over time, it's going to become desynchronized. Thus the need to occasionally, and only occasionally, bring it all the way down. If you leave your laptop on, that allows your laptop to drain the battery into that final drop-off. Then when the battery sees that, then it knows, ah, now I'm able to realign myself with that discharge point. And that allows it to reset its otherwise just sort of ad hoc tracking of energy in, energy out.

So that's the reason why occasionally you need to bring it all the way down, so that your battery management technology is able to synchronize. But the rest of the time it is much better for it, as I originally said, to keep it charged up near the top because just the way the chemistry works, that's what the lithium ion battery is happiest having.

TOM: Yeah, I think a lot of people get confused because nickel cadmium batteries had memory, and they kind of - they mix that up with lithium ion. I'm not saying that that's what our emailer did. In fact, I'm pretty sure he didn't. But, yeah, that does confuse the issue. Lithium ion doesn't have memory. And what you're saying is it's okay every once in a while to drain it all the way down because you might want to recalibrate. But you don't want to drain it down all the time.

Steve: Correct.

TOM: But it's really tempting with an Amazon Kindle because it doesn't need to be plugged in that often. A laptop, you use it unplugged for a while, a few hours, maybe six hours it's going to start giving you alerts. A Kindle won't, and so you kind of forget it needs to be plugged in.

Steve: Right. And I think that's a perfect example because when we were talking about it last week, a cell phone is the same way. Most people, because you don't really get more than a day of use out of your cell phone, you're in the habit of docking it at night and charging it back up. It would be a little better for it if it was convenient to charge it at the office or during the day at some point, if you weren't using it, to sort of give it a midday boost just to keep it up because it's continuous deep cycling that ends up aging the lithium ion chemistry faster than the same total amount of current flow which is kept more up near the charged state.

TOM: I keep my batteries plugged in as often as possible. I don't see any shortness in their life. The only thing I've run into with lithium ion batteries, a couple of times I have forgotten to turn them off. I've put them into sleep, just closing them, and forgotten to turn them off when I got on an airplane, and they have swollen up because of that. Now, over time that has gone away, if I don't do it again. But I actually had to replace one battery because it swelled up so much from being on during takeoff.

Steve: Yeah, there's gas that is produced, and that will cause the individual cells to bubble up.

[lruggier]

^ I am very confused, can you just answer my original question with a simple answer--

Is it harmful to my laptop if I charge it up to 100% when it is just at 75% battery? Or should I wait for it to die until I charge it?

Since I have been charging it for the past month before it died I feel like the battery is having trouble holding charge more than 3 hours when it usually can hold up to 4-5 hours. Have I ruined my battery? All the power settings are on the same settings as before, which are the lowest ones.

[DrJohnSmitherson]

You're really cute lruggier :D

[KillTheIrishman]

The old "charge and then let it drain and then recharge" scenario just doesn't work anymore and i'm not sure that it ever did.

[+Warwagon MVC]

^ I am very confused, can you just answer my original question with a simple answer--

Is it harmful to my laptop if I charge it up to 100% when it is just at 75% battery? Or should I wait for it to die until I charge it?

Since I have been charging it for the past month before it died I feel like the battery is having trouble holding charge more than 3 hours when it usually can hold up to 4-5 hours. Have I ruined my battery? All the power settings are on the same settings as before, which are the lowest ones.

Lithium Iion batteries like to be kept charged. They don't like to go below 10% and they REALLY don't like to be run down to Zero. So charging it when it's already at 75% doesn't hurt at all.

[Intersect]

its not recomemded to fully charge when only at 75% but laptop/mobile phone device battery will lose there charge capaicty over time

so after a year you will find they dont provide the time stated when you got it new.

its not harmful to the laptop, its jsut harfull to the battery. if you need extra power during lessions

get your self a new battery thats been fully charged for stand by on the day you need it. a new battery will still lose some charge if its not

inuse so dont worry.

[Shadrack]

Is it harmful to my laptop if I charge it up to 100% when it is just at 75% battery? Or should I wait for it to die until I charge it?

No, it isn't harmful at all. There could be some issues where the charge detection system isn't reporting an accurate % of charge, but charging a lithium ion battery from 75% to 100% should not harm the battery at all except that:

* The battery can only be charged a limited number of times (in-line with its "life" expectancy).

* You want to avoid charging the battery in a hot environment. So long as it isn't wrapped in a blanket or something, you shouldn't have this problem. But charging in a hot car, for instance, can really harm a battery.

Apple seems to say that it isn't full discharges that cause the trouble, but a deep discharge - for example, the result of a battery left fully discharged.

This is true about any lithium ion battery. The battery *shouldn't* drop below a particular charge or else its own internal circuit will be permanently damaged and incapable of holding any charge. For instance, if you have a digital camera that you rarely use and you forget to charge it last time so it is almost on empty and then put it away for a couple of months you will probably find that the battery is useless.

[lruggier]

THANKS EVERYONE YOU GUYS ARE THE BEST :D

I called Toshiba explaining my problem and I convinced them to send me a new battery for FREE since I have an extended warranty for 2 more years. If this happens with the next battery I guess it really only does give you 4-5 hours for the 1st year, but as of now I am convinced that I messed it up by charging it while it had more than enough battery left (aka when it was at 50% or higher) just so I could get it to 100% and then take out the battery.

My battery used to last 3 hours and still have another hour or 2 left and now it barley lasts 3 so thats why I made this post in the first place because I have only had it for one year, how can the battery die at 3 hours already its still very new!

[Detection]

THANKS EVERYONE YOU GUYS ARE THE BEST :D

I called Toshiba explaining my problem and I convinced them to send me a new battery for FREE since I have an extended warranty for 2 more years. If this happens with the next battery I guess it really only does give you 4-5 hours for the 1st year, but as of now I am convinced that I messed it up by charging it while it had more than enough battery left (aka when it was at 50% or higher) just so I could get it to 100% and then take out the battery.

My battery used to last 3 hours and still have another hour or 2 left and now it barley lasts 3 so thats why I made this post in the first place because I have only had it for one year, how can the battery die at 3 hours already its still very new!

Well you have 2 batteries now, so if you are worried one will run out before you get home, take the other charged one with you ;)

[lruggier]

Nope, I have to return the defective one so I won't be charged $142 :s

[Detection]

Send them a melted lump of plastic and explain you can not understand how it lasted this long in that state :innocent: :whistle:

[Shadrack]

THANKS EVERYONE YOU GUYS ARE THE BEST :D

I called Toshiba explaining my problem and I convinced them to send me a new battery for FREE since I have an extended warranty for 2 more years. If this happens with the next battery I guess it really only does give you 4-5 hours for the 1st year, but as of now I am convinced that I messed it up by charging it while it had more than enough battery left (aka when it was at 50% or higher) just so I could get it to 100% and then take out the battery.

My battery used to last 3 hours and still have another hour or 2 left and now it barley lasts 3 so thats why I made this post in the first place because I have only had it for one year, how can the battery die at 3 hours already its still very new!

There is also the possibility that you just had a faulty battery... IDK, I myself have had mixed luck with lithium ion batteries. My iPhone 4 battery is almost 2 years old and it still holds a charge like it is new. However, I noticed a drop in battery life on my iPhone 3GS just after 9 months of use.