Laptop Battery Life

[stephec]

I have a HP laptop with a 17" screen that's just over a year old, and gets used about three hours a day.

Just lately it's been showing about 30% battery remaining and suddenly cutting off as if the battery is flat. The only way to get it going again is to plug it in to the mains and use it like that for a while until it charges up a bit.

When it's not in use it's left plugged in on charge almost permanently, could this be doing any harm, and does anyone have any ideas for me?

 

[twowheelsgood]

It shouldn't make a difference as the laptop manages the charging for you. Its doesn't "overcharge" which can damage cells.

Interestingly (or maybe not) Li-ion not only has a certain number of charge cycles (often quoted anywhere between 500-1000) but it also has a shelf life too. Cells deteriorate whether used or not. They also last better fully charged (or at least 80%) which is why you should put your lights away fully charged this summer.

There'll be a whole load of mobile phones and electrical gadgets that'll end up useless solely because no one has manufactured a new battery in a while.

 

[RecordAceFromNew]

One of the problems is heat shorten their life, and laptops can run pretty hot. Charge dropping significantly after one year is not unusual.

Regarding the 30%, there are a couple of possibilities. One is that the power management setting is set (intentionally or unintentionally) to shut down/hibernate at 30% (on mine one can set it to whatever % one wants). The other possibility is that the charge level needs recalibration.

 

[chemswot]

While the cells don't overcharge, having the Li-ion batteries at 100% degrades them (resulting in less capacity) quicker than if they were partially charged. Also, the heat that your laptop produces would further increase the rate of degredation. More detailed info... (there's a table that summerises just below the fold).

+1 to advice RecordAceFromNew. Was just writing that myself...

 

[slowmotion]

I think it is supposed to be a good idea to "cycle" the batteries. Ie, fully charge them, remove the charger, and let them run down in use. If you leave the charger always plugged in, the battery never gets "exercise", and its life is shortened. I could have got this all scrambled BTW.

If you need to get a new battery, shop around on Google. The replacement for my Dell notebook would cost £105 direct from Dell. An online retailer supplied me with exactly the same battery for £35.

 

[stephec]

One of the problems is heat shorten their life, and laptops can run pretty hot. Charge dropping significantly after one year is not unusual.

Regarding the 30%, there are a couple of possibilities. One is that the power management setting is set (intentionally or unintentionally) to shut down/hibernate at 30% (on mine one can set it to whatever % one wants). The other possibility is that the charge level needs recalibration.

I've had a look in the power settings in my control panel, but can't find anything that lets me change the shut down %. I can't find any way to recalibrate the charge level either.

 

[Garz]

I've had this happen to my work laptop, very annoyed but like said earlier after a year this will happen (especially on cheaper models). My wife's macbook has probably been the best battery laptop ive seen. She's had it about 3 yrs now and only just started to play up, it has monster lifetime when not plugged to the mains.