182564 Views 374 Replies Latest reply: Mar 6, 2014 9:27 AM by Dave Marsh
• Calculating status...
Currently Being Moderated
Apr 4, 2012 1:11 PM (in response to atl7187)

I'm curious how long it will last

• Level 1 (5 points)
Currently Being Moderated
Apr 4, 2012 1:32 PM (in response to deggie)

• Calculating status...
Currently Being Moderated
Apr 4, 2012 2:14 PM (in response to apoc_reg)

I can't believe this performance was considered acceptable by Apple. The charging time from 20% to 100% is 4 hours, but if you drain it, and charge from a completely dead battery, it only charges at 10% an hour. This makes a complete cycle of usability 10 hours of usage + 4 to 8 additional hours. The iPad 1 and 2 took under 90 minutes to charge, making their complete cycles 11.5 hours.

Apple if you can't fix this problem through software, which I highly doubt you can, will you please recommend a charging solution to resolve this?

• Level 1 (0 points)
Currently Being Moderated
Apr 4, 2012 2:25 PM (in response to Krzysztof Przygoda)

It took not so long as I thought :)

• Calculating status...
Currently Being Moderated
Apr 4, 2012 8:45 PM (in response to Dariosa)

The iPad 2 battery is 25 Watts

The iPad 3 battery is 42.5 Watts

Now USB 2 charging specifications is 5 volts at a maximum of 1.5Amps.

Now Apple charger specification is 5 Volts at a maximum of 2.1 Amps.

If iPad 3 is being charged at 5 Volts then let's do the math.

Power = volts x current

At 2 Amps max current with 5 volts rail you have 10 Watts, so to charge a 25 Watt battery you will need roughly 2.5 hours.

At 2 Amp max current with 5 volt rail you have 10 Watts, so to charge a 42.5 Watt battery you will need roughly 2.5 hours multiplied by 4 which is 10 hours maximum.

Remember that the charging is charging above the maximum spec for USB 2 at 2 Amps which is 0.5 Amps more. With 25 % more charge than maximum USB allowed your lengthy charging time of 10 hours will start generating heat and this heat becomes run away as current starts to increase and the efficiency of charging is reducing dramatically until most of your charging is lost as heat into the charger and then is also transmitted into the iPad itself.

These losses are I x I x time loses that is current multiplied by current multiplied by time which equals heat loss.

Now take 0.5 Amp as the excess current and multiply it by itself 0.5 x 0.5 then multiply it by time = 10 hours.

That is whopping 4.5 Amps run away towards a 10 hour charge. That is not safe is it?

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 6:30 AM (in response to waitamoment)

Excellent analysis sir.

• Calculating status...
Currently Being Moderated
Apr 5, 2012 1:34 PM (in response to Dariosa)

Add me to the list who is seeing battery drain when it's plugged in and in use.

Suggesting to turn the brightness down to 50% isn't really helpful as at that level the screen is nearly too dim for me to use without eye strain (some of this due to issues with degernative eye issues).   I'm not running any games, just browsing in safari.   It's quite annoying.   Coworkers are not seeing this problem on their 3rd generation iPads, so it seems ot be an issue that is affecting some but not all devices.

This is plugged into the power outlet 10watt adapter, not to the USB port, I just did a restore on the device and it didn't make a difference.

• Calculating status...
Currently Being Moderated
Apr 5, 2012 3:05 PM (in response to apoc_reg)

To fix this problem, when you first boot up you brand new iPad, (has to be the first start up) let it drain, DON'T CHARGE IT. Charge it when it is completely dead, and that should do it. Until apple has accepted the fact that there are problems with the iPad, do this.

• Calculating status...
Currently Being Moderated
Apr 5, 2012 3:12 PM (in response to dylan69)

This is yet another FIX MYTH.  I am on my 3rd new iPad and on my current one and the previous one I let the battery deplete 4 complete cycles and it did not fix anything.  The problem is with the iPad using twice as much power as the charger can provide.  It's simple math.

Someone on another forum is going to make a video of their claim that their iPad is functioning perfectly normally and stays charged while plugged in.  If this is true, than a huge lot of new iPads are defective and Apple needs to come out and admit it promptly.  Also, if true I plan on forwarding both the video of my iPad and his iPad to the major Apple reporting sites as well as Apple themselves and YouTube.

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 3:13 PM (in response to Bellatone)

Did you drain it right out of the box? And what is that video called?

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 3:35 PM (in response to dylan69)

Not much of a fix if you've been using the iPad since day one of release.

• Calculating status...
Currently Being Moderated
Apr 5, 2012 3:39 PM (in response to boosted6spd)

Well...the battery in the new iPad IS 70% larger than the first two iPads. So common sense would say it SHOULD take longer to charge. And if you don't prefer to charge your iPad over night, which again, common sense says that would be the EASIEST (then it doesn't have to be obsessed over how slowly it is charging) way...then you don't have to, and you will just be watching and waiting. Sorry. You know what they say: a watched pot never boils.

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 3:43 PM (in response to colin scott)

Yea but if your someone who just ordered it, and is interested in trying to fix this, then who cares it snot like its gonna hurt you to do this...

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 3:45 PM (in response to katinak67)

Yes your right. But why woudln't apple be smart and create a faster charging USB? Compared to the 10 watt USB that's included in all iPad's, why not bump it up to 25 watt? 1/2 of the new iPad's battery wattage. I call that being smart.

• Level 1 (0 points)
Currently Being Moderated
Apr 5, 2012 3:47 PM (in response to katinak67)

I'm not obsessed at how slowly it charges.   I charge it overnight.   I fully understand that a larger capacity battery takes longer to charge.

What I'm obsessed over is the fact that even when it's at 100% charge, it drains even when plugged into the wall charger when being used.   This means that during the day at work I need to be mindful of how much I use it since I want a good charge for the train ride home.

Again, this is not about a slow charge, this is about the drain while it is plugged into the wall with the supplied power adapter while in use (even with the screen at 50% btw)

1 ... 12 13 14 15 16 ... 25

#### More Like This

• Retrieving data ...

#### Legend

• This solved my question - 10 points
• This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.