Question I couldn't find anywhere about the battery!

Question

Hi people!
I've tried to find the answer to my question pretty much everywhere but couldn't really find it anywhere!
This is from the user manual I think:
+For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Be sure to go through *at least one charge cycle per month* (charging the battery to 100% and then completely running it down).+
So they say that you should run down your iphone to 0% at least once a month, but I do it everytime I use it. Is that bad? I never recharge my iPhone when it's not completely empty or at least under 5%.
All answers I had found were to the opposite question: Is it okay to recharge it when it's not completely empty. But yes, that wasn't what I was looking for.
I hope someone can help me!
Edit: Also, when they say to run it down, do they mean run it down to 0% when using it, or leaving it on once it was charged to 100% and let it empty itself without using it?
Message was edited by: Anon M

Answer 1

They do not say to run the phone down all the way. They say "one charge cycle" If you drain the battery to 50% remaining, recharge it to 100%, then repeat that process once more during the month, you have completed one FULL charge cycle that month.
A charge cycle is one full discharge/charge cycle, or the cumulative equivalent thereof made up of multiple partial discharge/charge cycles.
FULL discharge cycles are deleterious to Lithium cells - they reduce the useful life span much more so than more frequent partial cycles do.
The only reason to ever do a full or deep discharge cycle is to re-calibrate the battery indicator as the battery ages (since it inherently looses capacity over time), but personally, I likely only ever do such calibration cycles every 3-4 months, if that frequently.
The whole point of using smart Lithium cells is you can partially discharge and charge them all you want and they will last as long as possible (they DO have a finite useful lifespan, as does any and every chemical battery). I keep a charger at work, at home, in the car, and use them whenever it is convenient to do so, regardless of the charge state on the phone. That way my iPhone always has plenty of power when I need it, and its battery is likely to last as long as possible.
P.S. I used my 3Gs like that too, for some 19 (?) months, and its battery will still power that old iPhone for a good 5 or so hours of use (I'd estimate that it is still good for about 80%-85% of what it was capable of when new).
Message was edited by: Michael Black