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nyc4lifedt

macrumors member
Original poster
Aug 19, 2009
49
0
I'm reading a lot of battery issues and recommendations on how to improve my battery performance.

I know that calibrating my battery by draining it doesn't improve my battery performance.
One interesting opinion was to drain the battery all the way down and charge all the way back up to calibrate my battery with the gauge. I wonder if this is necessary, or better yet, whether it makes a huge difference. And also whether it's safe.

I've never calibrated before. It just seems a bit contradicting to me, how it says you should not run the battery all the way down, but it recommends running it down at least once every month or two. It's not healthy for the iPhone battery to be completely drained but do it at least a couple of times? To me that's very confusing.

I do see some issues with my battery usage. It fluctuates a bit I think. It will say, 55% and jump up to 58%. Or It was around 45%, then drops down to 38% in a matter of a few minutes. I do notice when it's almost full or is above 80%, I don't have the fluctuation issue.
Doesn't occur all the time, and it's not something that I can pin point to an Apple Representative or a Genius. I wonder if calibrating would be enough of an solution for me.
 
Battery calibration only makes your icon or percentage more accurate. It does that and nothing else. Every time the battery is fully drained a small percentage of remaining life is removed, which is why more often than monthy calibration is not recommended.
 
Here is a question to tag onto what this fellow is saying. Is there an app out there that gives you the voltage and amperage of the battery?

Something people arn't taking into consideration on the % issue that when the phone shuts down the batery is not dead. It has mearly dropped in voltage to a level that can not keep the iphone running stabily so the software shuts down the phone. Your Battery is not drained all the way. It is just at the lower limit of its usability. So since you are not running the battery dead running it down till it shuts off a few times a month to calibrate it should not hurt the battery.
 
Every time the battery is fully drained a small percentage of remaining life is removed, which is why more often than monthy calibration is not recommended.

That is true with any battery though... and every time you charge ANY battery you are deminishing its life. You only risk damaging a battery when you drain it completly and the only way you can deplete the iPhone Battery completly is to change something in the software.
 
how big of a difference could there be? Are we talking about less than 5% of battery meter off, or could it be in teens and 20s?

If the number is small, I don't think it's worth it to drain it all the way just so that it reads accurately. If it's off by less than 5% I think I'll just live with it.
 
how big of a difference could there be? Are we talking about less than 5% of battery meter off, or could it be in teens and 20s?

If the number is small, I don't think it's worth it to drain it all the way just so that it reads accurately. If it's off by less than 5% I think I'll just live with it.

It could be a large difference, but if it's a small amount I wouldn't worry about it.

Stop looking at the meter before you go crazy. :)
 
I am not sure I am understanding your question but let me toss this out to you and if I get any of my fact incorrect don't worry .... I will be corrected promptly...

the iPhone gives you a warning at 20% and 10% and then at 1% the iPhone turns its self off theu software.

Now depending on how this software is writen it may say that "When battery reads 1% left turn off"

or

It may say "When Main Battery reaches X Volts DC and Y Amps Turn iPhone off"

I would venture to say that it was written by engineers who prefer volts and amps vrs percentages.

so by running the iPhone down you are putting it into a position where it is at the lower threshold of power so it "learns" or "Calibrates" that position as 1%.

the same is true after you charge it. It reaches a certain Voltage/Amperage and shuts off the charging circuit. (over charging is just as bad if not worse than running battery to dead 0 volts.)

So when you ask if it is a few percents off who knows what yours is. Mine was off by about 15% when I got it. Now it shuts off right at 1%
 
The iPhone firmware prevents complete draining of the battery of the sort that would cause damage. The only way of draining the battery like that is storing the phone discharged for a significant period. Running your battery down to shut-off will cause negligible marginal wear on your battery vs. two half-cycles, especially if done only occasionally to maintain your battery's calibration. And think about it: calibrating your battery is the only way to get an accurate feel for your battery's health anyway.
 
wow 15%??? that's a big difference. I guess there are tradeoffs in doing the calibration. i haven't had my phone go as low as 4% or so but never had it drain all the way to a point it turns off itself. so calibrating the battery DOES hurt the battery by 0.4 percent although it sounds minor. I guess I'll do some more thinking and testing.
 
I've read somewhere (finding it again, IDK) is that there is a 0.4% decrease (the number is from memory, but could be wrong, and is negligible as you say) in battery life from when the battery turns off from going normally dead.

In other words, if your figures are right (they sound a little high to me) running the battery out causes 1.6 cycles' worth of wear, as opposed to 1 cycle for two half discharges. So you might get to 80% battery health between one half and one day sooner. If you do it every couple of months you might cut a week, tops, off your battery life over the life of the phone.
 
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