Hi guys. I’m sure I could find an answer by trolling through countless electronics forums, but I thought this would be much easier.
My question relates to electronic devices that do not have a removable battery, such as the iPhone. These batteries are designed to die after 400 or so cycles [ie. planned obsolescence] and are not replaceable by consumers.
Here’s my question: when I am using my phone while it is plugged into the wall [or into my computer via USB], is my phone drawing power directly from the AC source, or is it still drawing its power from the battery? In other words, does the AC power merely keep the battery charged to 100% while the battery still powers my phone?
To put it a 3rd way, am I preserving the life of my battery by using AC power as often as possible?
Even when not discharged/charged, they lose about 20% capacity each year. There is also a limit of a few hundred charging cycles. Charging them twice from 50% to 100% is one cycle etc. So, if it is plugged in and charged - you are not harming the battery, if anything, you are helping by avoiding a charging cycle.
Yes, a couple of my words were poorly chosen. After 400 cycles, the battery will lose a bunch of its capacity [but won’t die]. See Apple’s own website: Batteries - Maximizing Performance - Apple
By not making the battery user-replaceable, is that not the very definition of ‘planned obsolescence’? Why don’t they sell replacement batteries in cell-phone stores, like Nokia and Motorola do?
a) Because the iPhone i an extremely sleek and small device, it needs to devote as much volume to the battery as possible, to get as much talk time as possible. Devoting area to latches and connectors gives up potential battery volume, and so Apple made the decision not to do it.
b) Apple is moving away from user-replaceble batteries in most of it’s devices. As with the iPhone, they have determined that the increase in battery life and decrease in weight of the device far outweighs the downside of user-replacability.
c) Apple is concerned with destructive battery failure caused by inferior third-party batteries. By making the batteries replaceable only by Apple (in theory), they reduce that potential for a lawsuit.
Finally, there are plenty of service centers that will replace the battery in an iPhone.
He might be an electrical engineer but apparently he doesn’t know very much about battery chemistry. One of the inherent flaws of lithium-ion and lithium-polymer batteries is their comparatively low number of charge cycles before failure. And the chemistry does not provide for a linear failure marked by linear loss of capacity, like nickel-based rechargeable batteries-- Lithium-based goes kaput and it’s very much like falling off a cliff.
Sorry, a latching mechanism will not reduce the usable space for the battery. This suggestion is not based on reality. Any design worth his salt (And I’m pretty sure Apple has at least a few of these) can easily design a mechanism that will take up no more space than is being occupied by the current shell of the phone.
Are you now suggesting that a latching mechanism adds significant weight to the phone? Do you realize many manufacturers use plastic mechanisms that are of the same, or nearly the same material as the rest of the housing? Please explain how a latching mechanism and removable battery door will decrease the weight of the device.
Interestingly enough, the rest of the manufacturers have been able to carry on with aftermarket batteries being used in their phones, and any device failure by the battery will quickly and easily be disclaimed by the manufacturer.
It’s quite clear that your opinions are not based on reality, and there has been such of the type of folks that make these sorts of shortsighted claims about Apple. I will not be direct and engage in namecalling, but I will say that your post did not fight ignorance.
Sorry, someone who is “responsible for the lithium battery” will be well aware that lithium rarely goes beyond 300-350 charge cycles. And the battery is outsourced anyway, there are only a handful of manufacturers in the world.
Sorry, I have to call bullshit on your post. The evidence does not support your conclusion.
ETA: Note that keeping the phone plugged in does not introduce charge cycles to the battery.
Actually, the evidence does support his conclusion. The iPhone 3GS has the highest talk time per oz in CNet testing of any largescreen smartphone, and one of the highest overall, indicating they actually ARE getting more battery cells by not including a case. After four years, battery replacements on iPhones are very low, indicating that Apple was in fact right when they said that the battery life would outlive the device for most folks. And the MacBook Pros increased battery life more than 50% without an increase in weight by going to non-replacable batteries…again what the Apple engineers said would happen.
Seriously, what other reason could they have for doing it? You really think Apple can’t afford engineers to tweak battery management, or that all of them are incompetent? Or that they do things like make the batteries non-replacable just to annoy Apple haters who wouldn’t buy one anyway? The iPhones have been out for years, the iPods for even longer. Where are all the reports from angry users whose batteries have failed?
Yes, ideally the batteries would be replaceable. But to claim that this wasn’t an engineering tradeoff done for valid engineering reasons seems counter-intuitive, faced with the obvious success of these products, making Apple the third highest market capitalized company in the world.
I am not sure if I am reading the same article as you are, but the IPhone only has noticeably “good” talk time if the 3G radio is turned off. With the 3G radio turned on, it’s middle of the road at best.
I am not sure why you are bringing up laptops here, as we are talking about cell phones.
Um, forced obsolescence and customer captivity? Is that really a question that needs answering?
It was not an engineering decision, it was a business decision. What Apple’s market capitalization has to do with the discussion is beyond me, it certainly doesn’t have any relevance to the fact that the decision to make the battery non-replaceable was not one founded on the science of electricity storage.
This article makes no mention of your “friend” being responsible for the design of the Iphone battery, nor does it mention that the decision to make the battery non-field replaceable was monumental. In fact, it doesn’t even mention that your “friend” worked on the Iphone (in fact it doesn’t even mention the word Iphone), and it states your “friend” left Apple in 2005.
I never claimed that he worked on the iPhone. You wrote, “He might be an electrical engineer but apparently he doesn’t know very much about battery chemistry.” Please read my reply in post #11 above.
Charge/discharge cycles are not as simple as 1 cycle = any recharge point. It does not work like that. Li-ion batteries deteriorate due to cycles, time, temp, and length of time at states of discharge.
Ideally a Li-ion battery has the greatest life at 40% capacity, which is the level (apx half charged) which is the best to store it at. It has a shorter life at 100%, but much much shorter at 0%. So try not to run it down that much, and when that happens try to recharge it as soon as practical.