To drain or not to drain? A New York Times reporter takes on Verizon over a dead cell phone battery and how it was caused. Not satisfied with Verizon's response that her battery was "overcharged" due to overnight charging, she set out to prove them wrong.
The answers she found?...
1) A battery cannot be overcharged, once it is full the power is cut off.
2) It's better to not let your battery get too low, because it cannot handle the strain and will inevitably shorten its life. So after half-empty (or half-full?) plug it in.
Do you buy it? We're a bit skeptical, we've heard too many urban myths about how to extend the life of our laptop batteries and they keep dying on us. The bottom line, in our opinion, is that batteries are just one finicky bunch.
Image: Ali Douglass for the NY Times
© 2009 Apartment Therapy
there is a myth about batteries (i mean the type for cells & laptops). charging it all night WILL NOT hurt it. i read that it would in real simple. so, i asked my honor student friend from mit (they know everything). he said they are designed to be ok if you "overcharge". however, it is better to wait till the battery is low to charge it.
Most electronic devices these days use Lithium-Ion rechargeable batteries, including my Nokia cell phone, iPod, and PowerBook. As explained in the article linked below, lithium-ion batteries "partial discharge to deep discharge", which is exactly the advice given by the NYT article.
http://electronics.howstuffworks.com/lithium-ion-battery2.htm
It's worth noting that it wasn't too many years ago when most electronics used Ni-MH or Ni-CD rechareable batterise and not lithium-ion, and that Ni-MH adn Ni-CD batteries DO prefer to be fully discharged before recharging and CAN be damaged by being charged overnight.
It's important to know what type of rechareable battery you are talking about when seeking or giving advice. They are not all created equal.
Since I just got a brand new battery for my laptop and have charged, uncharged and charged it again, how long can I expect it to last before having to recharge?
Li-ion batteries wear out most for the last bit of top up charge that goes into them. Recharging too often is to be avoided, and so is full discharge. I'd guess that using the battery to as low as you can go without chance of unexpected emptyness and then a full charge is best.
However maltreatment in this way will not suddenly kill a battery; just reduce its life somewhat.
anne-
I don't think there is a simple answer to your question. The length of time a battery lasts depends on lots of factors including what's going on in the background (both with your software and hardware), the brightness of your screen, the type of laptop you have. Look up your manufacturer's estimations, but keep in mind they are just ballpark figures.