Question about battery cycling

I searched before posting this, but didn't really find what I was looking for. A coworker was telling me today that he thinks he may have killed the battery in his previous laptop by ALWAYS having it plugged in and never letting the battery actually cycle, meaning letting it die completely and recharge every once in a while.

My 1721 is plugged in 99% of the time, I'm mostly at home with it, and I rarely use the battery power (only had it for about 2 months). Should I periodically let the battery die completely and recharge it, or is it better to always keep it charged?

 

If you never use your battery, it's ALWAYS better to keep the battery out of the laptop and around 40-50% full, stored at room temperature. Li-Ion batteries kept at 100% will slowly lose their charge capacity, although once your battery's charge cycles are up it will also die

Example: My previous laptop, a 5 year old Acer Travelmate 800, had a battery with ~4 hours battery life at purchase. I sold it a few months ago and still got around 3:45.

My parents bought an Acer Travelmate about a year after I did, but always left their battery in the machine, and used it more frequently (not much more though). That battery now gets about 45m before dying.

edit: There are quite a few care guides about Li-Ion batteries floating around the web too. Google ftw!

edit edit: Yes it's also considered a good thing to cycle the battery at least once a month. That is, charge it to 100%, use until maybe 5 or 10%, then charge up to 40-50% and store again.

 

So I should keep the battery out of the laptop complely? Never heard of doing that.

I do use it sometimes, I have to take it to work with me about once a week, so it would be easier for me to keep it in.

I'm not trying to be one of those people that asks what I should do and then disagree with it, I just want to be sure what the best thing to do is.

 

Keep the battery 40% charged and store it in cool dry room. Some people even keep it in the refrigerator! but not freezing of course.
For batteries under constant use, discharge it fully every 30 cycles or so. This is to calibrate the battery meter.

 

Great username and avatar. Hackers is one of my all time favorites.

So the concencus is that I should keep the battery out and stored, until I need to use it?

 

Yep. It will preserve the charge cycle and slow down the aging process so that the battery will last longer.

Also, the Battery guide is a good read.

 

Thanks for that great link!

It looks like that according to this, for my purposes, leaving the battery in is going to best. I do a lot of work on my computer for school, my apprenticeship program, programming for work, and having data lost to not having backup power is not something I can afford to have happen. So by following the rest of the care instructions in that guide, I should be able to make my battery last for a pretty average lifespan. If it turns out I have to buy a new battery in a year or 2, so be it. I'll probably be upgrading machines by then, anyway.

Thanks to everyone for the good responses!

 

Kind of random (but related) question: is it okay to remove a battery while the computer is running, but plugged into AC power? I often forget to remove the battery when I connect my comp to AC at home, and wonder if I should shutdown the machine before going ahead and removing the battery.

 

Yep it's fine. I do it all the time. I think they call it 'hot switching' or 'hot swapping,' I forget