Batterygate: Apple's Dysfunctional iPad 3 Battery Charger

[obsessed2]

iPad3 owners may want to keep their iPad plugged in even after device says it is fully charged to ensure they can get an extra hour of run time:

http://www.zdnet.com/blog/btl/batter...79?tag=nl.e539

[Penforhire]

Sony e-readers did this for years now.

[RainingLemur]

It's a feature! 100% for us is only 90% for them.

[elcreative]

[moderation edit] Lithium polymer batteries in everything show a 100% charge usually around 80-90% and take anything from a couple to four hours for an actual full charge... [moderation edit]

Edit: This comment now not accurate due to over eager mod editing... I do not support this statement and wish it to be deleted from this thread along with my other comments and references...

[obsessed2]

Originally Posted by elcreative

[moderation edit] Lithium polymer batteries in everything show a 100% charge usually around 80-90% and take anything from a couple to four hours for an actual full charge... [moderation edit]

My intent of posting this was not to give 'em another kick because it's Apple. If Apple wants to limit the charge of the battery to 90% that's OK, just report it as so without some outside testing entity finding out that 100% is actually 90%. For example, my Viewsonic gTablet shows full charge at around 96% and isn't reported as 100%. The only thing I take away from the story is that owners are losing about an hour of use without having to plug it back in. You say lithium polymer batteries in everything shows 80-90% at full charge but I tend to believe Dr. Raymond Soneira as being more credible in his analysis. Not making a big issue out of this, just informing.

[Belfaborac]

On the one hand, elcreative is quite right in that Lithium Polymer batteries do this in any and all devices in which they're used. Hence that part of the article is indeed an absolute non-story.

On the other hand, Apple's reply that continuing to charge the battery beyond the point when the indicator shows 100% will harm the battery is either a sign of utter cluelessness on the part of the Apple rep, or an indication that Apple has not implemented an automatic cut-off when 100% charge is really reached.

If the latter is the case, then that's a disaster waiting to happen for anyone who routinely leaves their device charging overnight, which is probably a majority of owners. I can't really believe that Apple would be that stupid, so I'm betting on a dimwitted rep.

[obsessed2]

Originally Posted by Belfaborac

On the one hand, elcreative is quite right in that Lithium Polymer batteries do this in any and all devices in which they're used. Hence that part of the article is indeed an absolute non-story.

On the other hand, Apple's reply that continuing to charge the battery beyond the point when the indicator shows 100% will harm the battery is either a sign of utter cluelessness on the part of the Apple rep, or an indication that Apple has not implemented an automatic cut-off when 100% charge is really reached.

If the latter is the case, then that's a disaster waiting to happen for anyone who routinely leaves their device charging overnight, which is probably a majority of owners. I can't really believe that Apple would be that stupid, so I'm betting on a dimwitted rep.

I'm an electronics technician. It's my understanding that all lithium batteries are essentially the same. Each cell in a lithium battery has to charge to 4.2 VDC and then the charger gradually reduces the charge current until it has dropped to a small percentage of the initial charge rate, at which point the battery is considered 100% charged. For most lithium batteries this is typically 2% to 3% although it can be a little more, as in the case of my Viewsonic gTab which is 4% with "fully charged" reported as 96%. The 10% to 20% you and elcreative are suggesting seems a little too high.


Dr. Soneira says that there is something wrong with the battery charge mathematical model on the iPad. He's saying that users will not get the maximum running time that the iPad is capable of delivering.

Dr. Soneira obtained his Ph.D. in Theoretical Physics from Princeton University and his background covers internationally recognized leading edge research in electronics, optics, applied mathematics, theoretical and experimental physics. So I think he is more qualified than you or I or most other members of this forum to speak in this regard.


It's almost my understanding that lithium batteries are smart batteries with a cutoff potential of 4.3VDC to prevent cell damage. Obviously the Apple spokesman is clueless and doesn't know what he is talking about. I'm sure he's taking the proverbial butt-chewing as we speak.

[CallOfCth'reader]

Belongs in the Apple forum.

[JSWolf]

Maybe not as this can turn into a general discussion about batteries.

[teh603]

Apple has always had issues with its batteries. iPods, Powerbook 5300s, and I think some of the early all-white iBooks all had massive battery problems.

[elcreative]

Originally Posted by obsessed2

I'm an electronics technician. It's my understanding that each cell in a lithium battery has to charge to 4.2 VDC and then the charger gradually reduces the charge current until it has dropped to a small percentage of the initial charge rate, at which point the battery is considered 100% charged. For most lithium batteries this is typically 2% to 3% although it can be a little more as in the case of my Viewsonic gTab which tops out at 96%, but not the 10% to 20% you and elcreative are suggesting. If this were the case every device would be DOA with 10-20% battery remaining. I typically recharge my tablets at 25% but they have dropped as low as 10-15% on occasion without completely dying.


Dr. Soneira says that there is something wrong with the battery charge mathematical model on the iPad. He's saying that the user will not get the maximum running time that the iPad is capable of delivering. Dr. Soneira obtained his Ph.D. in Theoretical Physics from Princeton University, so I think he is more qualified than you or I or most other members of this forum to speak in this regard.


It's almost my understanding that lithium batteries are smart batteries with a cutoff potential of 4.3VDC to prevent cell damage. Obviously the Apple spokesman doesn't know what he is talking about. I'm sure he's taking the proverbial butt-chewing as we speak.

[moderation edit] I only went by the spec details from various manufacturers and the way they say Lithium polymer cells work but a Ph D in Theoretical Physics obviously trumps the actual specs (do a search for 'em yourself) and even the article has connections to other posts casting doubt on the claim/way the claim is put forward...

[moderation edit]

Also these batteries don't overcharge by being left on charge, they have circuitry to prevent that... and it works very well if not mistreated... it also seems that we were discussing the top end of the charging displays not the bottom and, again if you read the manufacturers' data, the batteries shouldn't drop to zero (causes irreversible crystallization of the cells) so the display doesn't actually mean zero when it says that, it means within safe minimum before closedown until recharge... [moderation edit]

Edit: This comment now not accurate due to over eager mod editing... I do not support this statement and wish it to be deleted from this thread along with my other comments and references...

[CommonReader]

Most people feel brand loyalty to some extent. [moderation edit]

[obsessed2]

Originally Posted by elcreative

[moderation edit]. I only went by the spec details from various manufacturers and the way they say Lithium polymer cells work but a Ph D in Theoretical Physics obviously trumps the actual specs (do a search for 'em yourself) and even the article has connections to other posts casting doubt on the claim/way the claim is put forward...

[moderation edit]

Also these batteries don't overcharge by being left on charge, they have circuitry to prevent that... and it works very well if not mistreated... it also seems that we were discussing the top end of the charging displays not the bottom and, again if you read the manufacturers' data, the batteries shouldn't drop to zero (causes irreversible crystallization of the cells) so the display doesn't actually mean zero when it says that, it means within safe minimum before closedown until recharge... [moderation edit].

I never said everyone on here might not be qualified to speak at the level Dr. Soneria. Some can, some can't. I CAN'T. However, I respect his opinion. I simply mentioned I was an electronics technician so one could guage where I am coming from when I'm discussing MY understanding of lithium batteries. It has no other relevance.

I realize lithium batteries have cutoff circuitry and a low end cutoff voltage which prevents them from being fully run down to 0% and being damaged. From what I have read lithium batteries are seldom fully charged unlike other batteries nor is it desirable to do so. I have yet to find specs for a lithium battery which shows 80-90% is considered full charge. Again, I don't claim to be an expert and am open to learning.


It is my understanding that unless purposely limited a lithium battery will continue to charge to 4.2V and then the charger will reduce and end the charge at typically 2-3% of the initial charge and sometimes a little more. Again, I use my Viewsonic gTab as an example. It has a lithium polymer battery and reports being fully charged at 96%, the battery gauge NEVER reported 100%. Again, taking my limited research and understanding of lithium batteries I accepted this as normal, and I doubt most people would feel cheated if 100% was reported and it was actually 96-98%. However, in an effort to prolong battery life I suppose any manufacturer can stop charging the battery at whatever percentage they tell it to and report it as being "100 %" charged until an expert comes along and calls them out on it.

[carpetmojo]

I don't think anyone can say this eminently qualified expert in this particular field is ignoring the facts and kicking Apple - it seems to me he is in fact stating the facts.
As, again, it seems to me, he is particularly well able to do so due to his expertise.
And I think his background rather trumps (far beyond any "matching") anyone so far on the thread.

So I would tend to accept what he says, as it appears he is not ignoring the facts, but making them known.

[moderation edit]

[wqoq]

http://www.macworld.com/article/1166...warranted.html