new laptop and battery life

[Violet_82]

Hi there, I have bought a new laptop an acer 756 and I was wondering if anybody can give me any advice as to what to do with the battery the first time and how to make sure that it lasts long. What I usually do is this:
-laptop off, charge the battery overnight the first time (I leave it plugged in to the main even if is is charged)
-then the following day, unplug it, switch the laptop on and work on it till the battery goes down. At that point i switch the laptop off and chage it again till battery full. Then I switch the computer on and keep working.
So generally I never leave the computer on while charging, at least fr the first few months
Any advice really welcome
thanks

[BigPaw]

Some manuals suggest fully charging the battery, then using the laptop until the battery is completely discharged, then fully charge it again and then use it normally. This is a process called calibrating the battery.

Your laptop will likely have a feature called PowerPlus. This feature prevents your battery from fully charging to 100%, preserving the life of your battery. There is no harm in using your laptop while it is charging.

Experiment with the power options. Click on the Start button then choose Control Panel. In the lists that appears, choose the top option called, "System & Security". Now click on "Power Options" and have a good look around. All the settings are relatively self-explanatory, and you can always reset to defaults if you think you've done something wrong... and as you know, these forums are open 24/7 if you have any problems or questions about any features.

[Violet_82]

hi thanks, so you reckon there's no need to charge it overnight?

[BigPaw]

Think about this scenario, if you had been using your laptop before going to bed and suddenly realised that the battery was down to 40%, and yet you needed to use it on the train the next morning to continue preparing for a meeting, then it would be entirely sensible to charge it overnight. But, if there is no real reason to charge it over night.

So, sleep well, both you and your laptop. :)

[caperjack]

some,most makers ,suggest you charge and drain twice.me thinks

[BigPaw]

some,most makers ,suggest you charge and drain twice.me thinks

Some makers say, "no need to, at all." Some say, "once will do". Same will say, "at least twice". Some say," at least five times."

I would like to get hold of the "Some" people, and the "They say" people, and bang their heads together... figuratively speaking, of course.. :D

Ahhh . . . the Internet... :)

[Violet_82]

ok cool thanks, I charged it overnight in the end. One thing though, how about removing the battery completely and rely on the power cable instead? If so how do I store the battery for later/seldom usage? Do I have to charge it and stored it charged or let it discharge and then store it?

[caperjack]

laptop battery last longest when being used and dischard and regharged and not stored away

[sbesch]

This is admittedly a difficult subject. Partly because of the rather complex nature of LiIon battery technology and partly because there is a lot of mis-information out there about batteries. You should know that all LiIon batteries are charged by circuitry designed to protect the battery from both UNDER charge and OVER charge. If the battery voltage falls below a certain minimum, it becomes more risky to charge it and the charge supervisor will not charge it at all. For this reason, when the battery voltage starts to approach this minimum, the supervisor will simply disconnect the battery to prevent excessive discharge, at which point recharge is mandatory. This is also why you should not store a LiIon battery for a long time. All batteries will slowly discharge in storage. If the battery voltage falls too low, the charge supervisor will act as if the battery is defective and refuse to charge it at all, making a perfectly good battery appear to be shot. These can be recovered by trickle charging till the correct minimum cell voltage is achieved, at which point the standard charger will work again. The problem is that this trickle charging is best done by a specialist, since a mistake can lead to the cell either exploding or flaming out. The take home is that the battery should be kept charged. If you have to store it, then check it every week or so and recharge it if needed. (Panasonic recommends keeping stored batteries at 75% charge for maximum life.)

Similarly, when charging, once a battery is fully charged, it is important for both safety reasons and for maximum battery life to stop charging. All charge supervisors will stop charging the battery when it is fully charged. If you are using the computer at this time, the power supply will run the computer and the battery is essentially disconnected.

[sbesch]

I fear that the last paragraph of my previous post may have left the (incorrect) impression that leaving a laptop "plugged in" indefinately would "overcharge" the battery (i.e., in reference to the statement "it is important for both safety reasons and for maximum battery life to stop charging"). The point is that the charge supervisor would never let this happen. The only real reason to unplug the laptop's charger is so that you can remove it from the power mains and put it away. As was mentioned in a previous post, it's also a good idea to exercise the battery with periodic charge/discharge cycles, which will never happen if the laptop's charger is always running the Laptop.

[caperjack]

I don't know all the tech stuff of batterys ,but I do know that for most of[about 90%] the 3 1/2 yrs my wifes toshiba has been plugged into mains ,and the battery still charges and show full charge ,every now and then it gets use on the battery and last foe about 1to 1 1/2 hrs depending on what you are doing

[Violet_82]

thanks you all for the advice. I think I will not store it away then and keep it charged. sbesh, what you said is really interesting, but from experience I can say that if I leave the battery on all the time and keep the laptop plugged in the battery eventually wears out. I have another laptop a dell xps17 with a 9cells battery and the battery after few years of usage isn't performing as well as before. Why is that do you reckon?

[caperjack]

if I leave the battery on all the time and keep the laptop plugged in the battery eventually wears out

yes that is normal as a battery needs to be used ans then recharged for best life ,just charging it and leaving it un-use plugged in the laptop it will eventually be of little use, all battery will weventually die no matter whay way you use them as is the case with 9 cell battery from your dell ,same happens to people who have a 2 phone set of portable phones in there home,and only use the one phone with the other plugged in and unused ,battery goes dead and they go to the place they purchased the phone and say BUT I never used it hardly,it shouldn't be dead!
good luck with your batterys ,

[sbesch]

Well Violet_82, you sure don't ask easy questions! To really answer your question, the battery pack would need to be dissassembled and a formal failure analysis run on the pack. Having said that, I will try to pass back some ideas about what might be going on. I'll start with the phone analogy made by casperjack. First, I would be careful comparing Nickel-Cadmium (NiCd) batteries in a Wireless Phone with the Lithium Ion (LiIon) cells in a Laptop. Cell failure modes are very much different, and Second, NiCd cells are always wired in series while LiIon cells are wired in a series/parallel fashion. If one cell in a NiCd pack starts to fail, total pack voltage and maximum capacity of the pack will decrease. In the LiIon case, when a single cell fails, the fully charged battery pack voltage does not decrease since the good cells in parallel will support the full voltage but the battery pack capacity will be reduced. In your 9-cell pack by one third owing to the remaining 2 cells in one the parallel grouping now taking up all the load for that group. The other 2 parallel groups (of 3 cells each) cannot make up the loss because when the cell voltage of the 2-cell group falls, the computer will shut off the battery to protect the remaining cells.

However, this comes with another problem. The 2 remaining cells in the failing group are now seeing a 30% greater load than the other 2 groups (of 3 cells each), which puts additional strain on these cells. Since LiIon cells in parallel tend to become imbalanced with repeated charge/discharge (that is, one of the parallel set will charge faster than the others and this limits maximum charge capaciy), one of these cells may eventually get overloaded and fail as well, leading to further degradation and total failure of the battery pack. Often these overload failures are due to tripping of a small circuit breaker located in the tip of each cell. Believe it or not, I have actually reset these circuit breakers and discovered that what appears to be a completely dead battery pack still has a remarkable amount of life left in it.

So, why does leaving the battery on constant charge appeaer to shorten it's life? Well, in the case of the NiCd battery in wireless phones, the answer is a bit more clear. Constant charge of the NiCd cell has a tendency to harden the chemical structure of the battery, which is normally soft and porus with a large surface area. This hardening of the electrode material decreases its surface area and reduces cell capacity. That is why fully discharging a NiCd cell and recharging it will often rejuvenate it. All of the hardened electrode material is chemically broken down with the full discharge and then replace with fresh, high capacity material upon recharge. For LiIon cells the answer is no where near as clear cut. I'm afraid that I will have to use that dreaded 9 letter word and SPECULATE!

As the battery sits with the laprop plugged in and charging turned off, all of the cells slowly discharge due to inherent leakage in the cell. Sooner or later, the cell voltage will fall low enough that the charger will turn on and recharge them. Now, here's the speculation: None of the cells leak at exactly the same rate. The one that leaks the most will be "hidden" by the more slowly leaking cells. By the time the "better" cells reach a sufficiently discharged state to trigger recharging, the "fast leaker" will be a bit more discharged and as a result will not be completely recharged. After thousands of micro recharge cycles, the "leaker" gets fully discharged and fails.

I hope that this bit of techno-speak at least answers your question in terms of a possible answer.

[sbesch]

It is also worth mentioning that all batteries have a functional lifetime and limited shelf life. It may simply be that after several years, the batteries are reaching the end of their expected life, regardless of usage pattern.

[Violet_82]

thanks guys that really helps!