Possible Duplicates:
Is it better to use laptop on battery or on AC power?
What is it that kills laptop batteries?
I've heard that using a laptop computer on battery mode on a regular basis (at least two hours a day) Can prolong the battery's lifetime.
I'm not talking about increasing its duration per charge cycle, but its years of usefulness.
Is this true?
This reminds me of a recent Slashdot article, watch the video and it should become pretty apparent why constant charging it is not a good idea. So to answer your question if you have a lithium ion batter which most laptops have (I can't think of any laptops with nicad) it is not good to constantly charge and discharge the battery.
from the article:
As lithium ions flow from the positively charged cathode into the 200-nanometre diameter wires of tin oxide that make up the negatively charged anode, the nanowires writhe and bulge, causing them to expand up to 2.5 fold. The wires also change structure from a neatly ordered crystal to a disordered glassy material.
My thinkpad t410s has a feature that I can set the min charge level before recharging. I've got it set at 90%, so the battery has to drain down to at least 90% before it will recharge. My old T43 would charge whenever the battery level dropped to 99% and this has made the battery basically useless at this point (30% it's original charge capability).
Most battery manufacturers (li-on) also recommend that you discharge the battery fully about once a month, if you use it every day. This will help (I'm not sure why) to maintain a healthy battery. NiCad bats required this treatment more regularly, but Li-On bats also need it sometimes, apparently.
Today's laptops use Lithium batteries instead of nickel, but there's a lot of incorrect information out there about how to charge or drain your batteries, so let's set the record straight: Nickel batteries required being fully drained before a recharge to optimize your battery life, but Lithium batteries are the opposite—you do not need to fully discharge it before recharging, and in fact, if you fully deplete a lithium battery and don't recharge for a while, it can become incapable of holding a charge.
You'll also want to make sure that your battery is not always fully charged—Wikipedia points out that if your lithium battery is fully charged all the time, you will lose up to 20% of your capacity every year, no matter what you do. Make sure to discharge the battery sometimes, and if you spend most of your time plugged in at a desk, you would be better off running the battery down to half, and then simply removing the battery and storing it in a cool place. You can use Hibernate mode to save exactly what you were doing while still shutting down the laptop completely.
Found in: http://lifehacker.com/#!5566020/how-to-maximize-the-battery-life-of-your-windows-laptop
I think this sets it straight for me. Thank you all for your answers.
