What's the best for my LiON battery

Factual Questions
1

I have an MP3 player (Creative Nomad Jukebox 3) that uses a Lithium Ion battery. I usually run it off the battery, but occasionally I’m using it in a place with a 120V outlet. As soon as I plug the player in it starts charging the battery.

To keep the battery in the best shape, am I better off:

  1. Running off the battery until it’s discharged, then plugging it in
  2. Running it off the power cord, even though the battery may be only a little discharged, knowing that when I’m done listening the battery will be fully charged again
    or
  3. Removing the battery while I run it off the cord.

Your assistance is appreciated.

Thanks,

Steve

2

LiIon batteries don’t have the problems associated with overcharging that plague NiCd and to a lesser extent, NiMH types. You should be alright leaving it plugged in even if the battery isn’t fully discharged.

3

Yes, but don’t the batteries lose run time the more they are recharged?

4

Lithium-ion cells behave quite differently from e.g. NiCd cells. As opposed to NiCd, their life-span is very short, and there’s not much that can be done about it.
NiCd cells typically last thousands of recharge-cycles, if they’re taken care of, whereas Li-ion cells last a few hundred cycles - but almost independent of how they’re treated!

Even properly stored, a three year-old Li-ion cell will only have 50% of its initial capacity. If you use it a lot, it will degrade faster, but not dramatically so.

If you’re using it a lot, it’s better to keep it topped up when you can.

There’s a nice table at the wikipedia):
[ul]
[li] Unlike nickel based rechargeable batteries (NiCd and NiMH), Li ion batteries should be charged early and often. However, if they are not used for a longer time, they should be brought to a charge level of around 40%. Never use the battery care functions some cellular phones provide for nickel based batteries. (This will deep cycle the batteries.)[/li][li]Li ion batteries should be kept cool. Ideally they are stored in a fridge. However, they should not freeze. Aging will take its toll much faster at high temperatures. Keeping them in burning hot cars can kill lithium ion batteries.[/li][li]Buy Li ion batteries only when needed. Look at the manufacturing date. That is when the ageing process commenced. [/li]When using a notebook computer running from fixed line power over extended periods, it is advisable to remove the battery and store it in a cool place. [/ul]