<p>I agree w/ above. I hadn't "fully discharged" my iPod battery in a full year of use, so I though it might be time to do so — it would stay full for a few days, and then go to having just a sliver or two of life left. It played for 5 hours with an empty battery indicator before it shut off. It seems to be much more accurate now!</p>
<p>I've found from experience that a full discharge of a Li-ion will kill it. When I bought my iBook G3 in 2000, I got two batteries so I could switch them out if I had to on a long day (like if I took it to school to do a project for gifted where you occasionally used a computer for hours). Even when I wouldn't be swapping batteries, I'd try to swap the battery out every few weeks.</p>
<p>Sometime in 2004 I ended this process by accident. I was too busy with other stuff to change the battery that year and almost forgot I had a second battery. Meanwhile, my then four year old batteries were still getting almost 4 hours to a charge.</p>
<p>Then, disaster struck. My power adapter shorted out about a year ago. Almost a year ago to the day, in fact. The battery had maybe ten minutes left on it when I shut it down that day. I didn't get the new power adapter until the second week of September. When I plugged in the iBook, expecting my reliable old battery to charge, it wouldn't. The three week long drain (probably coupled with age) is what killed it. The second battery didn't charge either.</p>
<p>I still use this computer off the wall outlet and will probably have a new battery within the next few months (I'm going to sell a vintage computer to get the cash for it, since a $50 battery is about a third of what the computer is worth on the market now).</p>
<p>For some reason cell phones seem to hold old charges longer. I had this old Nokia phone in 2003, got rid of it that July, and had to turn it on to get my friend's stored cell number eight months later. The phone somehow still turned on.</p>
<p>i am so confused. i had been told before that it is a good idea to let your laptop run on battery every once in awhile... so i try to at least once a week... now, this is a BAD thing?</p>
<p>No. Newer computers will not let your battery drain so far as to kill it.</p>
<p>starcatch, it is a bad thing.</p>
<p>Lithium ion batteries aren't treated the same as other kinds. They should never be "deep cycled." They should never be drained.</p>
<p>To store them, reduce the charge to about 40% and put the battery in the refrigerator or freezer.</p>
<p>No it is not a bad thing. Beyond calibrating the battery once a month or so, there's not really any need to run it on battery for "health" reasons, but you shouldn't be frightened of doing running it on battery when you need it.</p>
<p>It is true that you should never fully drain a li-ion battery. But you can't ever fully drain it; unless you have a particularly crummy battery, the internal circuitry will never let it drain to the point of damage. </p>
<p>Also, while charge cycles do wear on the life of the battery, it's not significant. The major factors in lithium-ion battery life are: age, and temperature. The simple fact is that li-ion batteries degrade with age and high temperatures expedite it.</p>
<p>For more specific information, you can check your laptop's manual.</p>
<p>thanks for all the info! i'm definitely MUCH better informed now :)</p>