iPhone 4S battery, anyone else having this problem

[bsainsbury]

This isn't about the 4S's battery life, we all know that's an issue. I got the 4S the day it came out so I've had it about a month and starting earlier this week I noticed something weird with the battery. I will charge it at night before I go to bed and let it charge all night while I'm alseep. In the morning it says 100% charged but I when I unplug it, it drops down to 98% right away. It just started a couple days ago. I didn't think too much of it but this morning instead of 98% it said 97%.

Anyone else having this issue? Anyway to fix it?

 

[SL4VE]

your basically overcharging it, so once its fully charged it will drop down to 89% or so and than recharge. whereas the old iPhones would trickle charge at 100% to keep it topped up.

 

[bruinsrme]

your basically overcharging it, so once its fully charged it will drop down to 89% or so and than recharge. whereas the old iPhones would trickle charge at 100% to keep it topped up.

Is this documented?

 

[MrXiro]

Happens to my MacBook all the time and my Evo 4g.

 

[r2shyyou]

your basically overcharging it, so once its fully charged it will drop down to 89% or so and than recharge. whereas the old iPhones would trickle charge at 100% to keep it topped up.

From what I've been able to find on Apple's website, the iPhone 4S uses the same battery type (litium-ion) as the older models:

iPhone 4S specs
iPhone 4 specs
iPhone 3GS specs

As such, they should follow the same charging style. Below is Apple's documented info regarding the charging style of lithium-ion batteries:

Most lithium-ion polymer batteries use a fast charge to charge your device to 80% battery capacity, then switch to trickle charging. That’s about two hours of charge time to power an iPod to 80% capacity, then another two hours to fully charge it, if you are not using the iPod while charging.

I know it notes an iPod in the above but it should be the same for the iPhone.

Is this documented?

Below are links to Apple's battery documents, if you're interested:

Litium-ion Batteries
About iPhone Batteries

 

[SL4VE]

i "think" its due to the processor heat/speed etc not down to the battery for doing this. dont use it against me its just a theory.. HTC have issues like this on their 1ghz processor phones. im just adding my thoughts more than anything, but it makes sense

 

[orange42]

I've been having VERY good battery life lately, and when I unplugged mine today at 100% to go to work, I noticed it dropped to 96% really quickly so I was sort of wondering why. I turned off the phone then turned it back on and it was at 99%.