Battery calibration

Hello,

I own a latitude D610, and I been reading a dozen articles on calibrating batteries, and I just confused myself greatly. I am wondering what does it mean to completely discharge? Does it mean, turn off my critical alarm, and let it run down to 0%?

My battery is a lithium ion battery, and there have been articles conflicting on what they mean by completely discharging a battery. Some articles say go down to 0%, others say go down to 3-5%, and yet there are others that say 8% is fine. Some say that going down to 0% will hurt the battery, and others say going down to 0% is okay once in a while.

 

btw, the timing is terrible on the battery. When I let my AC adapter off, it says "3 hours remaining" but then out of no where like 10 mins afterwards it starts to say "1 hour left"

it is also terrible because when it says I got 8% left, next to it, it says I have 20 mins left remaining. Then no more than 4 mins after that, it goes to 4% and it says 8 mins left remaining, and goes into standby mode.

 

To completely discharge the battery means to run your machine on DC until the battery is dead. Same as when the battery in your car runs out of juice and no longer will crank or allow you to turn on lights, etc.

With the new batteries, that sort of calibration isn't normally required. With your machine there should be specific instructions on exactly how to calibrate, if necessary, and/or to what percentage you should allow the battery to fall.

In the case of my own MBP battery (about 18 months old) running it down completely seems not to have any affect at all. The machine still runs for a little over three hours just as it did when new. FWIW, I believe notebook batteries are usually only warranted for six months, so I guess I've been pretty lucky.

 

My dell laptop manual didn't give me detailed description either, just the same generic descriptions found on the web. My windows xp sets the critical alarm to 7% at minimum. After it goes down to 7%, it won't let me turn on the computer, and the LED becomes red. Should I turn it off, and let it run down completely?

 

When I recalibrate a laptop battery, I start at 100% and discharge the battery down to 3-5%. I then let the laptop recharge overnight (8 hours or more). Doing this once every couple of months should keep the battery calibrated.

If you do this and your battery gauge is still not accurate, you may have a worn battery.