My Phone & Lithium Ion Batteries

[rarisgod]

http://www.cellphones.ca/cell-phones/samsung-rant-m540/
There's the phone I have...roughly. But the point is, it has a Lithium Ion battery inside.

A friend of mine is continuing to let his phone (same one) die out each time before charging his battery. I, on the other hand, charge my phone whenever I am home, in the interest of not having to worry about it dying while I am out somewhere and might need to use it.

So I'm asking...which practice is better for the battery?
Let it drain before charging it?
Or charge it whenever?

I know that with some batteries, it's better to let them drain...and this is what we were advised to do the first time, the phone came with a partial charge and I was to let it die and then charge it up all the way...but does it still matter how/when I charge it?

[Stumbo]

I charge mine whenever the phone lets me know the battery is low.

From what I've read, lithium batteries do not have the memory effect and do not need to be discharged completely before charging.

[VroomVroom]

Everything I've read indicates that lithium-ion batteries are best kept between 30% and 80% of capacity. The reason that this isn't mentioned with small devices like cell phones is that the life expectancy of the device is shorter than that of the battery powering it.

Here's a link that semi-references that logic.

http://www.batteryuniversity.com/parttwo-34.htm

[rarisgod]

Thanks a lot, that link is all I needed!