Battery plugged in with 100%

[stevnim]

Probably the most important thing about battery and electronics lifetime is keeping them cool.

 

[thewitt]

Remember that the charging circuitry in the iPad is inside the phone, and not in the brick. It's one chip, and it's smart enough not to attempt to charge a battery that is already fully charged. The concept of trickle-charge applies, which means that a fully charged, plugged in iPad will cycle the charging circuit on and off at a specific threshold to maintain your full charge - and if your meter is calibrated, you may see a fluctuation of 2% or so while using your device plugged into the appropriate power source.

The brick contains one chip as well, that handles input power from 80v to 280v and moderates current as the device draws power from the brick. If the device is not calling for power, none is supplied.

This makes charging with the brick more efficient than charging from your USB port, which is MOST cases is not this smart. There are a few USB chipsets that know how to do this as well, but not many - in fact only one that I'm aware of, and it's used on the newest Apple and Dell products.

I could tell you how I know about these chips, but then I'd have to kill you...

 

[Munky]

I've had my iPad 1 for about a year and a half and almost always leave it plugged in when I'm at home. And when I'm on battery power I still get 9 1/2 to 10 1/2 hours of better life from 100% to 3-4% (lowest ill let it get) and its only ever ran completely down till it shut off twice. (fell asleep and forgot to plug in)

 

[1096bimu]

It is actually better to have it plugged in at all times. Because then it doesn't use your battery at all, which means less wearing on it. But don't get too crazy about it, why have 12hour battery life if you never use it?

 

[Milliebert]

When I bought mine, the Apple genius said not to use it plugged in. TO let the battery die each time, charge it fully, then unplug. It does indeed shut off when it gets to 100%, so charging overnight is fine, but as soon as it is in use, the charger kicks in whilst it's connected. So, when you see 98%, it will start charging again. I asked him surely it will cut off again and not charge when it's at a 100 whilst I'm using it and he said no, it will carry on charging... only when it's sleeping it stops. Rambling, sorry, but you get the gist. So I'll do as he said... that way it's his fault if he's wrong!

 

[jsh1120]

When I bought mine, the Apple genius said not to use it plugged in. TO let the battery die each time, charge it fully, then unplug. It does indeed shut off when it gets to 100%, so charging overnight is fine, but as soon as it is in use, the charger kicks in whilst it's connected. So, when you see 98%, it will start charging again. I asked him surely it will cut off again and not charge when it's at a 100 whilst I'm using it and he said no, it will carry on charging... only when it's sleeping it stops. Rambling, sorry, but you get the gist. So I'll do as he said... that way it's his fault if he's wrong!

In this case the "genius" is basing his advice on mythology. Try this experiment. Fully charge your iPad. Use it while plugged in. You'll find it never drops below 100%. Thus, the scenario you outline simply does not occur. To give the "genius" the benefit of the doubt he may have been talking about what would happen if your iPad was plugged into a source that could not charge as fast as you are draining the battery, e.g. your PC.

 

[Milliebert]

In this case the "genius" is basing his advice on mythology. Try this experiment. Fully charge your iPad. Use it while plugged in. You'll find it never drops below 100%. Thus, the scenario you outline simply does not occur. To give the "genius" the benefit of the doubt he may have been talking about what would happen if your iPad was plugged into a source that could not charge as fast as you are draining the battery, e.g. your PC.

Why are you inverting genius? It's what the techy guys are called, not what I think they are.

He was talking about plugging it into a wall, not the pc. It may be mythology but I'd rather take the advice of people who work with them every day, just to be sure.

 

[richsadams]

And with that the the OP's initial question has been asked and answered. Thread closed.