Third-gen iPad reportedly shows inaccurate battery level while charging - Page 2

Because if Apple is anything less than perfect, it's a scandal/conspiracy/bully.

Has more to do with the fact that the battery can charge very quickly until it gets to the very end of the charge. The battery really is very nearly fully charged but to prevent damaging the battery the last tiny bit of charging is trickle charged. It likely displays 100% a little before actually getting there so people waiting for their iPad to charge fully don't stand there gawking at it & wondering what's taking it so long to finish. It's probably more noticeable with the iPad 3 because of the increased battery size.

Apple have been playing fast and loose with icon indicators for years. They are not meant to be an accurate indication of the state of your computer, merely an indication.

Complain about how bad your cell signal is... Apple's answer: make the bars wider, remove one, and add in a longer averaging time so the number of bars in no way represents the data throughput you're currently getting (which is what signal strength measurement is about).

Likewise, the state of the battery is a complex and dynamic calculation. 100% means good enough to go out on the road. Any further than that and you're getting into diminishing returns territory (more time wasted tethered for little actual gain).

Does it really mean you battery can not take more charge? Hell no, but it's probably good enough for most purposes and, after all, you would not want to waste energy in that diminishing-returns territory 'cos then Green Peace would have a fit (and we certainly would not want that).

I'd like some proof they are playing "fast and loose."


Apple's error was not adjusting them specially for the iPhone 4. Why, because the bars mean nothing. Well, that's not entirely true. More bars means a higher dB than fewer bars... But that's it. Apple's problem was that the iPhone 4 was so good at the low end that when other phones wouldn't even work the iPhone 4 was able to make and maintain a call. When you can do this you shouldn't be showing no bars.

What we have are bars being referenced to a min and max dB level but no universal or patterned way to represent each bar. The user dowsnt know what the dB range range of 4 bar. They also wouldn't know what the dB was if you told them. The iPhone 4 just pointed out how poor of a measure it was because it could work better with less bars.

The battery doesn't have this issue because it's an absolutely measure of the capacity.


The percentage is very specific. It's a measure to the 1/100th and should be represented as such.

Sorry that you all don't understand battery technology, this is common practice for a large number of devices but no one notices because only iPad gets this kind of scrutiny. Would u really want to wait 2 hours for that last like 3-5min of use time? Read my post above regarding batteries & charging.

That's not what I heard. I heard that it was a simple formula error. There is a formula which is used to determine how many bars to display for any given signal strength. I believe this formula was provided by the carriers, although maybe it came from the chip manufacturers (or maybe it was even Apple's formula). In any event, the formula was incorrect for ALL phones - it had nothing to do with adjusting it for any given phone. In fact, the intent is that the formula is not supposed to be adjusted for phones - it is supposed to represent the amount of signal available, not the phone's efficiency.

AT&T released a new formula and Apple adjusted the number of bars displayed to match what AT&T's new formula said it should provide when they released iOS 4.0.1. At the time, AT&T was the only US carrier - I don't know what formula they used overseas.
http://www.apple.com/pr/library/2010...-iPhone-4.html
'To fix this, we are adopting AT&Ts recently recommended formula for calculating how many bars to display for a given signal strength. The real signal strength remains the same, but the iPhones bars will report it far more accurately, providing users a much better indication of the reception they will get in a given area. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see."

There's a nice graphical display of the old formula vs the new one here:
http://tech.fortune.cnn.com/2010/07/...-iphones-bars/

With Apple it is about the user experience. Not the hard numbers. As computer users, a bunch of us are pretty good at agonizing over the numbers. Apple has been trying to get us to chill for some time. For example, regarding download speeds - where are the old indicators that used to show us bytes-per-second in our browser downloads. It's not that we don't want to know about this very important figure it's just that, as a group we focus on it. Apple removed it. Now we're a little dumber but happier.

It's not difficult to give a good indication of Quality of Service (QoS) in communications devices but, if we were to see the actual signal to noise data we would freak out (and be very unhappy) so Apple (perhaps at the behest of the cell companies) dumbs it down for us and then throws in an averaging delay that means the direct correlation to data throughput and what I hear in a voice call is lost.

Battery measurement is about how much time I have left to charge and how much time I have left to use my device. Those numbers are not easy to determine, even if the user is not changing the parameters by actually (OMG) using the device. The charge function is a decreasing exponential and (as has been pointed out) probably has a safety component at the top end of the charge to soften the damage to the battery. Measuring current (no pun intended) battery capacity is like trying to measure how much gas you have in your gas tank by using a pressure gauge in the gravity fuel feed line. It is least accurate at the extremes of its range so Apple throws in an inverse exponential to make it look more linear and then gives us a number between 1-100 as an indication (or max minutes divided by that 1-100 number if you prefer).

These measures are not exact, their performance is not particularly well shaped to give us an accurate picture of what is going on. They are just indicators that give us a feel for the devices we use. I've no problem with that and I certainly would not hold off on buying the amazing devices that Apple produces because some of the indicators are somewhat fuzzy.

But the reality is that Apple plays with these indicators to make us feel good about our devices and not necessarily to inform us about how our devices are actually performing *right now*. That approach works for most people but does not sit well with a few of the more compulsive of us.

ps I love my Macs, my iPhone, and my iPad. But I do so for good reason. They work. They do the job I require of them. They don't get in my way while they are doing that job. It is a small price to pay to not be able to monitor them at a level of accuracy that suits me (but, perhaps, would not suit most people).

Where did you get these numbers? Did you make them up?

How do you know that it doesn't take 5 hours for the last 30 seconds of use? Gut feelings?

Maybe an extra hour of charging for an extra 3 hours of use?


Naw. It is 2 hours for 3-5 minutes. That's the ticket. Sounds right, so it must be right.


My ex- used to unplug her cellphone the moment that the battery indicator reached "full bars", and she would always complain that it ran out of juice too quickly. She refused to understand that it was still charging even when the indicator read full. After she spent money on a new one, I took her old one and fully charged it. It lasted for a long time. There was no problem other than her refusal to believe that "full bars" was not an exact reading, but instead, meant that it was "not near empty". It was calibrated to stay "full" until the battery started to reach the point where the user should start paying attention.

She also claimed to not be able to understand how to use the heater controls in her car. She got weird comfort from being the victim of her own intentional incompetence.

This is a feature of the iPad2 and the iPod touch as well. The display will show 100% yet the battery continues to charge. My practice is to let the device charge until the icon shows the 'electric plug' symbol, thus indicating full charge.

Cheers

Is it cool to charge your iPad battery overnight? I've heard stories about overcharging depleting battery life.

Those stories are about older battery technologies. With modern batteries, best practices have changed. It is no longer good to completely drain a battery before recharging it. Instead, long-term life expectancy of these batteries is optimized by keeping them constantly as close to 100% as possible.

Nope.
http://www.tuaw.com/2012/03/26/debun...s-own-battery/


ETA:
'Nope' refers to the part about overcharging depleting battery life. Leaving the iPad plugged in overnight is OK with an Apple charger. Of course, with a third party charger, it's not so clear.

I think what you actually meant is the opposite of what you posted.

(You answered "nope" to the guy's question when the correct answer is "yes, it is fine to charge the iPad over night)

You are correct. I was actually responding to his second statement (about depleting the battery life).

I'll correct my post.

I read an Apple support document that said it is good to completely drain the battery at least once a month and then charge it to 100%.

http://www.apple.com/batteries/ipad.html

If you read carefully, it says that a complete charge cycle helps with reporting of battery percentage accuracy.

The reason for this is that percentage indicators are based upon the declining voltage of batteries as their charge is depleted. That curve changes over the life of the battery as it ages. Time, environmental conditions and charge cycles all change that voltage-to-percentage-charge graph. A complete charge cycle allows the device to recalibrate the battery readout.

So if you're looking for the most accurate battery percentage, a full charge cycle is the only way to achieve it. However, keep in mind that lithium batteries don't respond well to those complete cycles. Their life spans are hurt by being discharged all the way. If wanting to make the battery last as long as possible before replacing it, keeping it fully charged is optimal.

This is why apple recommends doing it only once a month, a full charge cycle is actually bad for the battery. Thus it is a tradeoff between the value of an accurate charge meter vs slightly better battery life over the device's life span.

Great article on Macworld.

Analysis: iPad battery allegations unwarranted

I would suggest that a couple of FUD'r here read it and if they had any guts delete their posts.

Are you kidding? The Apple haters never admit that they were wrong. As soon as one piece of FUD is debunked, they just move on to the next.

Unfortunately, you are correct.

Too bad AI just doesn't make it a rule, i.e., either delete you erroneous comments or they will. And for those that think it would contravene their rights they should reread the First Amendent.

Thanks- good to know! It was always my understanding that depleting a batterie's life is detrimental, which was why I was surprised that Apple recommended it on their website.

Are you new to the internet?

But seriously, expunging wrong statements, even if possible, is not entirely desirable. Also of value is the entire record showing exactly who was wrong, what their thought process was, and how they were proven incorrect.

Back in the Nickel-Cadmium era, full charge cycles were indeed the best way to prolong a battery's long term life expectancy. Modern lithium based batteries are completely different.

Note that apple is only explaining how to get an accurate battery percentage. They don't say that this is the highest priority. Historically, apple has recommended leaving laptops constantly plugged in. Although I'm not entirely sure what their reasoning was. It could be in order to maintain a full charge and prolong life. Or it could be for a balance of reasons which have to do with average customer satisfaction across a whole host of issues.

Exactly. We're not the Ministry of Truth, nor should anyone want to be.

Though Internet shorthand as a whole seems ominously like Newspeak…

Not true.