Laptop battery longevity -- how to extend battery lifetime?

[theblue1]

When I was taking my laptop out everyday I made a point of letting it discharge completely before charging the battery -- and I was rewarded by battery sessions around 3 hours (down from 4.5 hrs when it was new two years ago, but still respectable, I think).


BUT... now that I'm at home more and not taking the notebook out every day I've noticed that -- if I haven't been through a discharge/charge cycle recently (ie, the notebook's been plugged in for days or even a week or two) that my first time out the battery life may be very short, indeed. Even under an hour, though usually closer to 2. But a big jump down.

If I put it through a discharge/charge cycle or two, everything's rosy until the next time it sits plugged in for the better part of a week [or more].


ANYHOW... now I'm bringing a new desktop box into my equation (it's under the desk, but you know) and so the laptop will be getting even less use, eventually.


I have two concerns, not surprisingly:

1) finding a way to make sure it's got a 'good' charge on it [of course, there's the option of simply running it through a discharge/charge cycle every couple days... that may be what has to be done]

2) extending the battery's lifetime, if possible [I've still got a year of paid warranty that I've never really tapped -- but, without checking the fine print, I'm pretty positive that batteries are excluded after a certain period.]



Any ideas?



______________

PS... now that I'm using my old 19" CRT again on the tower, I have to say I REALLY HATE the shiny glass on it -- as well as the convex surface which seems DESIGNED to catch glare at ANY angle... And THAT begs the question of what on EARTH the laptop makers are doing putting glass covers on newer laptops. It may help sell them in the store when Joe Double-Digit-IQ goes in and says, "Oooh, it's shiny and pretty," but, damn have you ever tried using one of those in daylight/outdoors? Meh. Even in my darkened room, the glare on this CRT is driving me bananas, already. Now I know why the laptop -- which I'd never thought would become my primary -- took overy from my tower and its 'big, beautiful' 19" CRT...

[towers]

thank for your vist post ,but you have to read this, if there are can help you:
"Keep in mind that no matter what you do, the charge capacity of a
battery will drop steadily and eventually will drop to below a useful
level. Laptop batteries don't last forever. It's kind of why you see a lot of perfectly good,older laptops being used sans batteries. The battery's died of old age, and either the laptop's too old to get a replacement battery, or
the replacement's too expensive for the owner (some have fairly
expensive generics available, but as I mentioned, some of them run
into the hundreds of dollars)"

[psychonaut]

Assuming its a lithium ion or lithium polymer battery (which pretty much every laptop battery is made in the last 10 years...)

The trick to longevity is plain and simple, use it. Leaving it plugged in all the time is your enemy. Leaving it discharged for periods of time is also bad, though probably not an issue here, if you ever have to store a battery, make sure it's charged at least 50% before letting it sit for an extended period, and "refresh" it with a charge every couple weeks.

It doesn't have to be a full discharge/recharge all the time. You can use it partially, recharge it partially. LiIon has no "memory effect" so it's not detrimental to use it partially and top up the charge.

The full discharge will "recalibrate" the circuitry that "predicts" how much battery life is left. (You don't want your computer getting confused, thinking the battery is dead when there's juice left because it'll blindly go into sleep/power down thinking it's out of juice when it's not. The re-calibration helps keep that straight). As a rule of thumb do a calibration at least once a month. But try and run it on battery for at least a little while every couple days. There may be a particular procedure for your make/model/OS to best calibrate it so google around for battery calibration.

So my tip in your situation, is simply unplug it and run on battery for a little while regularly, even if you're near an outlet. Doesn't have to be on battery til it's dead. Just for a little while to keep those electrons flowing.

The other enemy of battery life is heat. High heat will deteriorate your battery whether it's being used or not. So keep it out of a locked car on a hot summer day, and keep it in an area that's ventilated while you're using it. Even with the external monitor, don't run it with lid closed even if that's an option. On the other hand, cold will make the battery behave a little funny while it's cold but those effects are temporary and it returns to normal when you're back at room temp.

And otherwise, its a fact of life they don't live that long. 400-500 "cycles" and your battery is at 80% of where it started is considered a good run for a li-ion, 600-800 or even to 1000 is good for a modern li-poly. A cycle is a 100% discharge and 100% recharge; so if you use it from 100%->50 then 50->100 that would be a half of a cycle, etc.

Some batteries are going to last longer than others too, even the same model, even off the same production line on the same day. They vary and it's the luck of the draw some times. Your warranty will probably only cover the battery if it's longevity is severely diminished after a smaller number of cycles - that's how Apple does it, at least. The OS there shows you how many cycles the battery has been through in your system profiler. There's probably other tools that do similar in the PC world.

P.S. not many LCDs look good in the sunlight anyway - glass or no. Glare aside, they're just not bright enough! Especially laptops, who trade brightness for power use. The glass does trick the consumer into thinking it's brighter and has a higher contrast ratio than it does. It usually looks better in the showroom than in the real world!