Can anyone help??? (battery use)

[neda]

I have a 15" powerbook about a year and a half old. I mostly use it once or twice a week. Recently I have noticed that when I USE it , I plug it in the whole time and when I done its 100% charged. Later when i take it out to use it 5 days later or so the battery is only at 75% or so. Anyone have this problem or know whats up.
thanks

[iBlue]

I think it means it was still draining power (as it stopped charging at 100%) and the indicator light and icon in the menu bar was not "refreshed" as to its status. Don't quote me on that but it seems about right.

Try unplugging and plugging it back in an hour or so before you plan to take it out on battery life, and see if that helps.

(although I bet someone elese has some other ideas on the matter here)

[SC68Cal]

When you say that you unplug it, use it 5 days later the battery is down to 75%, do you mean that it was sleeping for those 5 days? It may still consume power while asleep

[mad jew]

I'm not sure I understand. A sleeping laptop will continue to use up power for the RAM and aspects of the logic board (RAM is the biggest factor). If it's not plugged in, then it'll drain the battery. :)

[miniConvert]

Are you still getting reasonable life out of that 75%? Batteries slowly lose charge anyway. Ok, 5% a day is a bit steep, but it doesn't sound catastrophic. Why not just leave the laptop plugged into the charger while it's not in use so it's always 100% when you're ready to take it out with you? If that's not what you do already...

Laptop batteries are funny. Kinda like toenails. I'll never understand them.

[neda]

I dont put it in sleep mode ,its off when I put it away.

[Azurael]

Lithium Ion batteries naturally lose charge down to about ~40% of their capacity when left for a period of time (how long that time is depends on the chemistry of the individual battery in question, some seemingly identical batteris can have a huge variance!) I used to have a Toshiba laptop battery that lose half it's charge in about 4-5 days days, even when diconnected and stored unplugged from the computer. It's actually quite damaging to the battery which is why they recommend storing Li-Ion batteries for periods of over a month about 50% charged.

I'm more worried about the fact that the Battery on my 15" AlBook now only lasts 40min :D Time for a new one, I think.

[neda]

Thanks I guess my battery is getting weaker, it a shame the laptop is mint and not used that much , you'd figure it would run like new

[mad jew]

Do you take care of your battery by calibrating (http://docs.info.apple.com/article.html?artnum=86284) it once a month? :)

[neda]

I have calibrated, but not monthly, I'll give it a try

[miniConvert]

Thanks I guess my battery is getting weaker, it a shame the laptop is mint and not used that much , you'd figure it would run like new
Li-Ion batteries, which I assume this is, start to lose capacity from the moment they are manufactured. You don't have to use it often to start losing capacity. Even so, it doesn't sound like yours is particularly bad.