iPhone 4 - first 5% of battery drops really fast

[Elliot B.]

Has anyone noticed that the first 4-5% of the battery disappears within 15 minutes after charging? Same thing happened with my 3G.

I'm guessing it's just difficult to gauge exactly how much the battery is or something?

[Singh400]

I think it is some sort of protection feature (ie stop over charging it etc etc). Other smart phones have been reported to do the same thing.

[Ghost5525]

I've kind of noticed that with the 3GS...might also be os4

[KamiQuazi]

I also noticed that after I charge over night it shows 101%. If it happens again I'll screenshot it.

[maash]

no issues with me. infact my first 5 percent drop slowest

[ady199]

Yep - I have exactly the same issue :cry:

[Elliot B.]

I very much doubt it's a fault, it's happened with most phones I've had. I'm just curious as to why it happens.

[.Blaze]

My iPod touch goes to 96% when I take it off charge but then suddenly goes back upto 100%

[RadishTM Veteran]

Haven't noticed it on mine. I fully charged it nearly two hours ago, currently on 97% charge and I've been using 3G a bit.

[kouhii00]

I very much doubt it's a fault, it's happened with most phones I've had. I'm just curious as to why it happens.

One of the reason of why it might happens is because when the battery is fully charged depending on the voltage specs for some devices in the phone the current leakage is slightly higher than normal and as a result draws slightly more current from the battery.

[Steven P. Administrators]

Has anyone noticed that the first 4-5% of the battery disappears within 15 minutes after charging? Same thing happened with my 3G.

I'm guessing it's just difficult to gauge exactly how much the battery is or something?

Thats like when you're driving almost on empty, you drve economically, and when you've tanked up.. The first 15 minutes afterward 5% of the tank goes because you don't drive economically anymore.

I'll get me coat.

[Pablo2008jedi]

Mine does too, it also reboots during phone calls! :angry:

[Tzvi Friedman Veteran]

I've had the same problem with my EVO. I've been told that when the battery gets to 100%, it actually using the battery for some tasks, so when you take out the plug, it may not actually be fully charged. I'm not sure how much sense this makes, but that's what I'm told by people in the know.

To test, I would leave your phone plugged in while turned off, and then see what happens after you unplug it and turn it on.

[halcyoncmdr]

Nothing out of the ordinary and pretty much all Lithium Ion batteries will show the same thing most of the time.

When the battery is charged up to 100% a circuit switches to prevent overcharging, it then waits until it drops a little (usually 5%) to top-up the charge back to 100%. Depending on when the charger was unplugged you may see it drop that 5% almost immediately, or you may not. It could also depend on how often the battery capacity updates (could only be every few minutes on some devices).

If people saw their phone charge to 100% then drop to 95% and keep going back and forth then they would probably freak out, that's what the uninformed masses do. Take something they don't know anything about and claim it has an issue. So instead to avoid that the device simply doesn't show the back and forth motion of the charge. In 99.99% of cases the different is so small it isn't worth worrying about.

[casabel]

Indeed it is nothing more than a protection feature for the battery...