mikec#IM
Well-known member
Um, that definition is "full charge cycle" is something I've never seen.
This is RDF at it's finest.
Not exactly what i'm referring to. My point is a "charge" is 0->100% and a discharge is 100%->0%.
THe effect on the lifespan of running a lithium polymer battery from 100%->90% and then back to 100% (ignoring circuits that prevent charging when it is close to charged, etc.) is less than going from 100%->0% and then back up to 100%.
And i just found on apple's website, this quote: "Charge Cycle. Using and recharging 100% of battery capacity equals one full charge cycle."
So your two examples above are not correct. In fact, apple says:
"A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could listen to your iPod for a few hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so you may take several days to complete a cycle."
So in your first example, that's a half charge (100->50) then in your second it's 20% (80->60). So combined that's 7/10 of a cycle (assuming you started with a full charge).
The only definition that matters is Apple's, since Apple is the company that said you get 300'ish charge cycles. There's no reality distortion field here. They are saying "you will get 300'ish charge cycles, and this is how we define charge cycle." It's only an RDF if you don't actually get that.
As an engineer, this definition is similar to the definition we used (though, again, we didn't base it on 100%->0%, but on 90%->10%.)
Um, I think the Apple RDF is in full swing. It's not "a full charge cycle"; it's a charge, discharge cycle, which may or may not include going over 90% charge or less than 10% charge.
Check out http://www.batteryuniversity.com for "less spin/more filling".
I don't not the expert on batteries, but considering the iPod and Macbook fiascos, I'm sure Apple isn't either ;-)
Apple is very smartly being conservative with the 300 cycle comments - sets expectation very low - I am sure many iPhones will last past 2,000 cycles.
It is RDF because Apple is defining the reality. As an engineer, you should understand fact from spin.
Well, that is certainly true."I'm just saying that's a bit scary--treat that "rental phone" like gold when you have it..."
How about just treating it like your own phone? If you lost your own phone during that period, you'd have to replace it too (assuming you didn't want to switch to a treo 850, now available in pink and green).
http://news.com.com/8301-10784_3-9739479-7.html?part=rss&subj=news&tag=2547-1_3-0-5
https://support.apple.com/iphone/repair/battery-power
Replacing the battery on an iPhone will be an expensive and nerve-wracking experience.
Many phones have removable plates on the back for easy battery replacement. Not the iPhone.
Apple revealed the details behind its iPhone battery replacement program this week. It's basically the same deal as with the iPod, in that you have to return the unit to Apple for battery replacement, but it's a little more expensive. The service costs $79 plus $6.95 for shipping to replace the battery on an out-of-warranty iPhone, and Apple says it will take three business days.
The service is also similar to the iPod in that all data is cleared from the iPhone during the replacement process, so you have to make sure that you back up all data on the device before sending it in. Apple says the iPhone battery is good for between 300 to 400 charges before performance will start to decline, which generally is the case for any lithium-ion battery over time. Usually for other phones, you can get a replacement battery and pop it in yourself.
Apparently they'll rent you a replacement for $29 for the duration of the round-trip repair if the phone is no longer in service at the time, fwiw.
Anyone else's definition is irrelevant (but see below where I call your bluff). Apple is being their own lexicographer.
They are saying:
1) you will get 300-400 charge cycles from the battery
2) a charge cycle is defined as _________
Note: think about it logically. Apple could have adopted the "charge/discharge" definition to make you happy, but then they would have spec'd the iphone battery at 600-800 cycles (because everytime you run the battery down by x%, you eventually have to charge it up again by the same amount, or eventually you can't discharge any further).
Now, to call your bluff and play your little RDF game, here's what batteryuniversity says about what a "cycle" is - (let me know if i missed some other definition):
What constitutes a discharge cycle?
"There are no standard definitions that constitute a discharge cycle. Smart batteries that keep track of discharge cycles commonly use a depth-of-discharge of 70% to define a discharge cycle. Anything less than 70% does not count. The reason of the cycle count is to estimate the end-of-battery life.
A battery often receives many short discharges with subsequent recharges. With the smart battery, these cycles do not count because they stress the battery very little. On satellites, the depth-of-discharge is only about 10%. Such minute discharge cycles put the least amount of stress on the batteries in space. With shallow discharges, however, nickel-based batteries require a periodic deep discharge to eliminate memory.
Lithium and lead-based batteries do not require a periodic full discharge. In fact, it is better not to discharge them too deeply but charge them more often. Using a larger battery is one way to reduce the stress on a battery. "
This seems pretty straight forward. It doesnt matter what anyone else's definition is if Apple not only tells you how many cycles it will last and tells you what it considers a cycle to be. They could call them anything at that point as long as they define them.Anyone else's definition is irrelevant (but see below where I call your bluff). Apple is being their own lexicographer.
They are saying:
1) you will get 300-400 charge cycles from the battery
2) a charge cycle is defined as _________
Mikec - Huh?
What are you talking about? Are you trying to say that you don't believe the iphone battery will last through 300-400 "charge cycles" as defined by Apple?
Or are you trying to say that you just don't like the words Apple uses?
Because if it's the latter, I don't think anyone cares as long as they know how long the battery will last.
And I don't understand your empirical data statement. I am sure Apple actually tested the battery or is relying on empirical data relating to batteries with similar chemistry and load profiles. Do you think otherwise, and, if so, where's your evidence? (Because, you know, you should be empirical too.)
And to what "de facto standards" do you refer? Sources, please.
Look, you can go on as much as you want and play semantic games to ignore the rules of logic and the laws of science, but right now I have no idea what you are even complaining about. It seems to me that the issues are this:
1) the battery is not removable and will eventually stop recharging (and its charge life will gradually decrease.) This is bad. We'd all like to know how long it will take before the decrease in charge life is noticeable. Apple says 300-400 full discharges. Based on apparent real-world discharge rates, this comes out somewhere in the range of 18-36 months. This is bad if it dies while out of warranty ($89 + rental). This is less bad if it dies in warranty (maybe rental fee, and certainly hassle).
2) apple may not be telling the truth. the battery may stop working sooner than 300-400 full discharges. Other than "reality distortion field" and "makes it's own reality" comments which prove nothing, probably the only facts supporting this are past experiences with apple ipods or notebooks, some percentage of which did not live up to stated battery lifespan claims. I don't know what percentage that is, which is a shame, because that would be "empirical data" which you love so much. In my own case I've had three ipods. One had the battery die right when apple predicted. One had the battery die way too soon. One still has the battery going strong, long after apple predicted. That's too small a sample set to draw any conclusions other than "your mileage may vary."
One thing to note is that the life-per-charge figures (talk time, standby time, audio time, etc.) figures quoted by Apple seem to be holding true for most people (with some doing a little better and some a little worse).
3) apparently you are a battery engineer and object to apple's use of terminology, despite the fact that their terminology seems to match the terminology used in the one reference you pointed us at (yeah, sucks when I actually read the thing you claim supports your point, doesn't it?) But, of course, "there are defacto [sic] standards out there" so by (supposedly) inventing its own terminology, Apple is a bad bad company. Clearly trying to confuse the public.
If you are trying to bring up a point other than 1, 2, or 3, please say so. It might be a very good point. I just don't understand it.
Agreed. it wasnt a huge deal to me that there wasn't a user swapable battery, but having it stuck to the damn MB sucks big time.What's REALLY upsetting is they soldered the damn thing to the board (unlike iPod batteries which aren't and so user replaceable using eBay purchases)!
Agreed. it wasnt a huge deal to me that there wasn't a user swapable battery, but having it stuck to the damn MB sucks big time.