Battery lifespan and charging question

[Zap]

Recalling the old days of rechargeable batteries, the rule of thumb for extending battery life is to use it until almost dead and charge it fully. Topping it off or repeated charging when not drained would eventually reduce the amount of charge a battery could hold.

My question is does this still hold true today, or is this just an artifact from the NiCad days?

My notebook is a Dell Dimension D800 with a Li-Ion battery. One of the rubber feet on the bottom of the notebook is attached to the battery. I use it often on AC power and I would take the battery out so that it isn't constantly being charged. However, doing so means one foot is missing from the bottom, making that corner sag when I'm typing. Am I doing the smart thing by removing the battery when it doesn't need to be charged, or am I being paranoid? TIA.

 

[Abhi]

As far as i have read, You should not discharge Li-Ions below 10% of the charge...

For the take out or leave in thing, its been discussed befroe, but no conclusion been drawn as yet.... I want to know too....

 

[Abhi]

http://forums.anandtech.com/messageview.cfm?catid=51&threadid=1273218

Other links...

 

[thuned]

Most, if not all, Li-ion laptop batteries shut off when not in use to prevent it from overheating. BTW, li-ion batteries are best kept at low room temperatures (what's that? like 20-25c or so?). So, if you battery happens to be next to the cpu, memory, hdd or whatever, removing it might prolong its life a bit. But if it's next to the mobo and optical drive, then you don't need to bother.

 

[Zap]

Originally posted by: Abhi
http://forums.anandtech.com/messageview.cfm?catid=51&threadid=1273218

Other links...

Thanks. I actually saw that thread already (after I posted this) and read some of the links. I guess Li-Ion batteries don't have "memory" like NiCad or NiMH. Some pages suggested "conditioning" Li-Ion batteries every two weeks or so by letting it run almost down, and then giving it a normal full recharge. And Ahbi is right about not letting the battery run "flat." Not sure on any percentage, but they shouldn't be run until totally dead. FWIW running "flat" also kills most car batteries, except for those labeled "deep cycle."

Well, now I feel a bit more confident about leaving the battery in. Not even sure I'll have the notebook long enough to end up with a dead battery anyways, but you never know.

 

[Conroy9]

According to www.batteryuniversity.com, the only reason to condition Li-ion batteries (let them run down once in awhile) is so that their charge indicator will remain accurate

other than that, it's better to charge them before they run all the way down