43

I have read somewhere that Li-Ion batteries live longest when charget to about 80% of max capacity. My friends' new Sony VAIO has an ability to charge to only 60% of max capacity in order to increase battery lifetime.
Maybe this could be implemented in KPowerDevil?
The downside is, of course, that you would have less time to work when you disconnect power cord but maybe the battery will last longer overall?
I think this could be a good feature, given that someone with more knowledge about laptop batteries would comment if its correct (I think it is) or maybe it's just marketing BS
And what % of max capacity is optimal.

Whatcha think?

What I think is that it's nonsense. Asking in IRC yields that Li-Ion batteries definitely don't like to be deep-cycled and should be kept topped up to extend their life, but nothing much about keeping them 100% topped vs 80% topped.

However I do know that I plug in my laptop 24/7 and the battery life sucks. But after rechecking the original specs I found it was designed to suck - it did feel to suck a little more than it should've though.

I'll let somebody else have a go at this one. Approved until proven otherwise!

There are plenty of opinions on this, but hard facts are difficult to come across. Certainly Li-Ion batteries don't suffer from the memory effect that earlier batteries did. Most manufacturers imply that keeping them fully charged causes no problems. Some manufacturers recommend that you run the battery down to ~10% every 6 months. Most manufacturers seem to suggest that you should consider 10% as critical, and not let them get below that.

It's worth googling - there are some very interesting articles on this. In the light of all I've read, I don't think there is any substance to your theory.

I read a little bit about batteries when I bought my netbook (note that I'll only talk about Li-on batteries).

Keeping a battery plugged in all the time isn't good because it'll be warm for an extended time. It shouldn't be that bad if you do it occasionally, as far as I know.

If I remember correctly, if you want to store a battery, it's best to have it charged ~40 % and put it in a cool place.

The "run batteries dry" thing is to calibrate the software to get a better estimate of the battery life. A deep discharge can be very damaging and is not recommended.

I haven't read anything about the OP's claim. Personally I think it doesn't matter that much, and by the time the battery is "bad" you probably want a new notebook. This is just me guessing - any references would be nice.

A good site with lots of information about batteries: http://www.batteryuniversity.com/

This blog post explain a lot about Li-on batteries life and includes references: http://www.teslamotors.com/blog2/?p=39

+1! old good ibm`s thinkpads have software to do that, this is crucial feature for battery life, it should be basic feature of powerdevil!

my Samsung notebook has an option in the Bios to stop the battery when it reaches 80%. I think it could be a good idea