Here is a question for which there are rabid responses on both sides on the internet! I am using Ubuntu 10.10 on an IBM ThinkPad t43. I have a 9 volt battery that I use only occasionally. Usually I use the AC connection and when I'm finished working I leave the laptop in "sleep" mode. (Not always, but often.) When using the AC is it okay to leave the battery in the computer or is it better to remove it? Some swear it shortens the battery's life to leave it installed when not in use. Others swear--with equal fervor--that the newer ion batteries know when they are fully charged and don't have to be removed. Which is true? It's inconvenient to keep taking the battery in and out, but if it's necessary to prolong it's life I guess it's worth it. Some clarity on this would be helpful because, as I said, you can find equally impassioned arguments for both sides of this issue. Thanks in advance!

What kind of battery is it, exactly, and how old is it?

Let's see, it's a Li-ion battery, 6600 mAh extended life battery (generic brand). I've had it about 4 months.

http://batteryuniversity.com/learn/a..._ion_batteries

States that Li-Ion batteries will live longer if you do not charge it all the way (though of course not charging it all the way means less runtime on the battery), so it would seem that taking it out when on A/C is beneficial.

In sleep mode you have to keep it in. If the ac drops then you loose your sleep info.


I always remove battery when I use ac alone and power off. IBM sent out a letter stating that it would make the battery last a bit longer but I do it for energy issues. Why charge a battery all the time when I am not using it?

I could see how this would be an iffy topic.

I rarely ever have to put my laptop to sleep however...

If I am doing something very time consuming like compiling a large package what I will usually do is remove the battery (before hand) and run it on AC during the time of the compiling.

Then I would turn the laptop upside down with the lid closed and leave it like that and do something else important.

Of course where I live the AC is very very reliable. Depending on where you live obviously it might be a bad idea to take the battery out.

I would assume that ACPI would just cut the power to the battery and switch to AC alone when the battery is charged. If not then why hasn't somebody implemented this yet? :-)

Ah, this is the point. I read somewhere that most computers today have something called "smart" charging circuits that protect the battery from overcharging. It's just a convenience not having to bother with removing and then reinserting the battery. But that's I think what makes the topic "iffy" as David said. Is it true that most laptops have these "smart" charging circuits?