Deep cyclying li ion batteries vs. charging at any point

[jboydjr]

Please help. I have the new iPod Touch (I love it). For every article I read saying NEVER to deep cycle a lithium polymer ion battery(for the "touch") I read one that says it doesn't make any difference when you recharge. Actually, the article I read (sorry not to have the link available) stated that it is damaging to the battery to deep cycle (to completely let the battery discharge before charging) because li is a light metal, etc.. Could someone with the real know please give me some feedback. It would be greatly appreciated!

Jim

 

[matrixshaman]

In general deep cycling any lithium ion battery is only going to destroy it or greatly shorten it's life. Deep cycling is normally only for Ni-cads and similar battery chemistries.

 

[mina]

Based on the info's that I've read, Lithium-Ion's generally last longer if you charge them often as compared to letting them drain too much before charging.

 

[jboydjr]

Thank you all! Well, the good problem is I have already deep cycled it twice now (just twice since I got it). I won't do it any more, but do you think I have damaged it already????

 

[turbodog]

You can't over discharge an ipod, or any other protected li-ion for that matter.

What running an ipod down to zero WILL do is allow the battery meter to properly calibrate.

Both the ipod and protected cells are just that, protected from over charge and over discharge.

Li-ion cells age from just sitting there. They age MORE quickly if they are left fully charged. But they also age from being used (as does any secondary cell).

In general though, the li-ion cell will handle however you want to treat it.

 

[Minjin]

My strategy has been to let lithium batteries go down to just below half capacity. My reasoning is that when they are fully topped up, their self discharge is at a maximum. So if you constantly top them up, you're in the worst part of the self discharge curve, therefore you must recharge more often, and hence wear out the batteries quicker.