it's known and anticipated: Bigger batteries take longer to charge from the same system as before which, for the iPad Power Adapter, is a 10W source.
Charging from a USB port is going to be positively glacial.
I'm sure they (Apple) would love to have amped up the charging source on this beauty, in the same way they did on the Power Adapter for the iPad as compared to earlier versions, but doing that would inevitably lead to some heating problems that would probably need more real estate to handle, i.e., make the size increase even more than they had to eat with the new battery capacity.
Sure would love to see iFixit, or one of the silly idiots who delight in taking the new iPad and crushing it in blenders or whatever for their moments of viral glory on YouTube, do something more useful and rig say a 15W charger and plug it in and see what happens.
Anyone volunteer to take that on?
Was your iPad sleeping while it was on the charger or was it active?
I ran some power tests yesterday. It's important to remember that not only does the new iPad have a battery that is 70% or so larger, it draws substantially more power when running (the reason for the new battery).
Testing with two different Apple AC chargers that I have, it looks like the total charge time for a sleeping iPad should be in the 5-6 hour range (that's going from approximately 0 to 100%). But… trying to charge a wakeful iPad takes more than twice as long as that. Most of the wattage being put out by the charger is going to run the iPad, not to recharging the battery.
You'll see similar effects if you're using the new iPad plugged into a USB port. My iPad2 would hold just about steady plugged into a standard powered USB hub, it would drop maybe 1-2% an hour. The new iPad drops more than 5% an hour. 5 W just isn't enough to sustain it.
Note that these results for wakeful iPads are going to depend very much on the brightness setting for the screen and the processor load. There's no way I'm going to tear my iPad apart and run proper tests on it, but it wouldn't surprise me if at the extremes power consumption ranges from under 5 W to over 10 W.
Not being willing to dig into my precious toy, I have no idea if the internal circuitry can stand much more than 10 W of charging power. If it can, I wouldn't be surprised to see a “fast” 15-20 W charger become available. There are some users who will be vexed by the substantially longer charging time. With the older iPads, you could pop it on the charger over breakfast or lunch and get enough juice to run for the next half day or over dinner to carry you through the evening. That's not going to be the case with the new iPad.
Absent such a “fix” we're just going to have to make some mental adjustments and consider this the price we're paying for a whole slew of major improvements.
pax \ Ctein
[ Please excuse any word-salad. MacSpeech in training! ]
PS: note to hosts––sorry about the URLs in my sigs in my previous posts. It's just embedded in the macro boilerplate and I don't notice it. I'll try to remember to edit them out by hand. Sorry for putting you guys to the inconvenience.
Thanks for some usefu information ctein but apple should be releasing a better charger with it. Its going to make the iPad far less convinient for high volume users.
For instance I watch netflix on my ipad while i go to bed so it tends to be on all night... the iPad 2 would still be fully charged in the morning and ready for a full days usage at work.... now I cant do that :-(
I agree that it unfortunately impacts heavy users like thee and me.I am having to rethink my iPad "lifeflow" [g].
But don't jump to a conclusion about what Apple *should* have, yet.
We don't know that the iPad circuitry can support 15-20W of charging power, or if there are other issues running that many watts thru it. We'll need to see what reports come back after the hardware hackers dissect one and experiment on it.
I do think this will prove to be the low spot in the product curve. My guess is that more people will complain about the longer charging time than Apple expected and the 2013 iPad will either be a bit more power-conservative or be able to accomodate shorter charge times. But that's a guess based on years of product watching, not inside info, so don't treat it as anything more than crystalball-gazing.
pax / Ctein
drained my battery around 12noon yesterday and set it aside to charge. A little before noon today and it's FINALLY at 100% battery.
I used it here and there but not anything substantial. Just to clarify what I'm reading, it's a combination of the charger and bigger battery?
Thank you David for posting this, I was just about to call Apple. I still might seeing as mine took almost 24 hours to charge...
I meant to say that's from the point of view of the user. There may well be very good technical reasons why it's so long and unable to run and charge efficiently but thats not going to wash with the general user.
I do think this will become big news that almost make the iPad 2 the better option. (almost.... that screen is nice ..!)