iphone loses charge when using while plugged in

1 to 2 percent isn't much. I'd probably not worry about it. I honestly think people worry to much about their battery, make it into a huge problem that its not. But then again, I only see it from my perspective.

I would try to take that USB extension cable out and try that for a few days. Just to see how it works without it. If its still dropping 4-5%, then its not the cable.

Try to use the phone down to about 50%, and then charge it over night. See what you get then.

It discharging while plugged in tells us that the drain on the battery while in use, exceeds the capacity of the charger. Use a larger charger, like for the iPad, and it should not happen.

If you keep you phone charged through usb every single day the battery will star to become "addicted" to the charge process, so when you remove it from the charger, it will run down quickly. I personally only use the charger when necessary, plug it in to itunes, sync and then remove it.

Run your battery down between 5% and 10% and then fully charge it, or better yet, run the battery down fully until it switches off, and then do a full charge and try not to use the phone too much while it is charging

I do this a lot and my battery is in very good shape.

JetBlack7 said:

If you keep you phone charged through usb every single day the battery will star to become "addicted" to the charge process, so when you remove it from the charger, it will run down quickly. I personally only use the charger when necessary, plug it in to itunes, sync and then remove it.

Run your battery down between 5% and 10% and then fully charge it, or better yet, run the battery down fully until it switches off, and then do a full charge and try not to use the phone too much while it is charging

I do this a lot and my battery is in very good shape.

Click to expand...

That only applies to NiCa batteries. Lithium Ion batteries do not get a memory so always charging them is fine and has no long term problems.

As to answer the question what is happening when the battery gets to that 97-100 charge it drops to a tickle charge to prevent overcharging it which might be less that what the phone is pulling and this will happen with any charger,

I had a similar problem with a cheap car charger. When I would plug in the phone, it would make the standard beep, and show the battery icon, so I knew the phone recognized a power source. However, even sleeping, the battery just drained and drained....it NEVER gained a charge. I replaced the charger with a more reputable brand, and it works fine.
Even though you are using the charger that came with the phone, either the charger or the cord has gone bad.

Make sure to sync the battery

The battery's used in apples products are "lithium" battery's. After charging it a lot of times, it sometimes cant tell how full it is so it gives "Estimates" to avoid too much of that, every few days make sure to drain the battery to 0% and let it shut down on its own. then charge it and dont touch it until it gets back up to 100%. This will sync the battery and it will give accurant numbers to how "Full" it actually is.

It could be the extension cable.
The iPhone draws either 500mA or 1A depending upon which charger is used.
The USB standard uses 2-wires for power and 2-wires for data and Apple is using these wires in a non-standard way
The Apple charger actually puts a small amount of power onto the data wires in order to tell the iPhone that it's plugged into the wall and can draw the full 1A.
A computer USB port or some other non-Apple compliant charger will not put power onto the data wires (or put the wrong amount of power) and that will cause the iPhone to only draw 500mA (charging slower) or to not charge at all.
This data-power signal is a very specific voltage and any change in wire type or length could be throwing off the reading by your iPhone.
I have some aftermarket charging cables that, even when used with an actual Apple charger, will trigger the "This accessory is not supported" message.

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_3 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5)

Remove the extension or buy an iPad charger and keep the extension as above.

I don't use an extension or anything when charging my iPhone but I have seen it happen to me as well. Never too worried about it because it never was more than 5% or something. Also I can stream a movie from iTunes to my iPad via Home Sharing with the iPad plugged into the iPhone charger and during the whole movie it'll only charge like 10%.

benhollberg said:

I don't use an extension or anything when charging my iPhone but I have seen it happen to me as well. Never too worried about it because it never was more than 5% or something. Also I can stream a movie from iTunes to my iPad via Home Sharing with the iPad plugged into the iPhone charger and during the whole movie it'll only charge like 10%.

Click to expand...

These chargers only have a limited capacity. While using your device you can exceed the capacity of the charger and actually deplete the battery a few percent.

Stealthipad said:

These chargers only have a limited capacity. While using your device you can exceed the capacity of the charger and actually deplete the battery a few percent.

Click to expand...

I know, like I said, I am not too worried about it.

When the iPhone hits 100% it stops charging and won't start charging again until it's down to about 96%, at least that been my experience. Shouldn't be anything to worry about.

Fernandez21 said:

When the iPhone hits 100% it stops charging and won't start charging again until it's down to about 96%, at least that been my experience. Shouldn't be anything to worry about.

Click to expand...

I'd say that's my experience as well.

Gav2k said:

Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_3 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5)

Remove the extension or buy an iPad charger and keep the extension as above.

Click to expand...

An iPad charger won't help.
If the phone isn't charging at max on it's current charger then a bigger charger isn't going to help.
Rechargeable devices draw (suck) power -- power isn't forced into them.
If you're drinking through a straw it doesn't matter if you put the straw into a glass or a raging river -- you're only going to suck what the straw and your mouth can accomodate.