9 hours 34 minutes later...

[STEVESKI07]

Totally bogus.

25-35% were just a mental estimate but it's got to be close. Maybe not on standby but with normal usage. I left a very memory intensive page open one day by accident and my battery went down to 75% by noon when normally my battery is still around 90% by noon. I wasn't doing anything else excessive that day. Whether you want to call me bogus or not, it is a fact that your phone will have a noticeable about of battery loss from leaving web pages open.

 

[digitalfx]

I thought the appeal of Apple was that you didn't have to micro manage their devices?

where did you hear this??? The iphone lacks in a number of ways for a 3rd gen device. (the lack of a today screen, the lack of app management are two glaring features that should have been included in the os long ago)

If you think you can get 9+ hours on a charge with both wifi and gps turned on, you are not being realistic....it aint gonna happen.

 

[Eso]

If you think you can get 9+ hours on a charge with both wifi and gps turned on, you are not being realistic....it aint gonna happen.

How do you make the leap from having the iPod play with the screen locked to using the GPS and WiFi for 9 hours? Or is your phone dead after 9 hours of WiFi and GPS standby?

 

[SpaceKitty]

Location Services is what is killing your battery, turn it off and turn it on only when you need it, without Location Services on I can get 2 days of normal use between charges, with it on depending on my travels I can get 8-9 hours before a charge is needed.

Location services does not use extra battery power. Mine stays on, allong with push contacts, calendar and mail, 3G on, notifications on, wifi on, and I get about 1.5 days with about 9 hours average usage.

The phone is designed to leave everything on.

 

[-aggie-]

25-35% were just a mental estimate but it's got to be close. Maybe not on standby but with normal usage. I left a very memory intensive page open one day by accident and my battery went down to 75% by noon when normally my battery is still around 90% by noon. I wasn't doing anything else excessive that day. Whether you want to call me bogus or not, it is a fact that your phone will have a noticeable about of battery loss from leaving web pages open.

The safari page is open or not? I can see what you say, if the page is actually open and having to update. However, if you're back at the home screen, not using safari, then no.

 

[digitalfx]

How do you make the leap from having the iPod play with the screen locked to using the GPS and WiFi for 9 hours? Or is your phone dead after 9 hours of WiFi and GPS standby?

Not sure what you are asking??

In your 1st post (POST #1) you said that during your test, your settings were:
Settings are:
3G on (full bars)
WiFi associated with a network
50% volume
50% brightness (screen was off anyways)
Location services on

If you leave WiFi and GPS on as you did, you will get a very short battery life.

 

[anjinha]

If you leave WiFi and Location Services ON all the time, you will NEVER get 9+ hours on a charge. Those services should be turned on as needed or pay the price.

Location services doesn't drain the battery AT ALL if you're not using any apps with GPS. Listening to music with the screen off doesn't use Location Services at all.
Wi-fi being on only drains the battery more if you're actually using internet or if you have "ask to join networks" on, because on that settings wi-fi is always looking for networks. Otherwise it's fine to leave it on.

I always have wi-fi and location services on an my 3G lasted at least a day and a half.

 

[anjinha]

OP, how's the 3G signal at your house? If you have poor 3G reception having 3G on will drain your battery very fast because the phone will be constantly looking for signal...

 

[STEVESKI07]

The safari page is open or not? I can see what you say, if the page is actually open and having to update. However, if you're back at the home screen, not using safari, then no.

What I'm saying is when you are on the home screen. It is still keeping that page in it's memory, whether or not it is doing any processing. That is why when you open up Safari the page is already loaded and it does not need to access the web to retrieve it again.

Here's a small test. I have an app called FreeMemory which tells me how much free memory I have available on my phone. Right now I have 99.81 MB free (should be higher, phone probably needs to be restarted, but will still work for an example). This is without any page loaded in Safari. Now I will go into safari and load Yahoo home page. Hit the home button and go back into FreeMemory and it now says I have 84.10 MB free. I now go back into Safari and close out Yahoo. Now that nothing is in Safari, I go back into FreeMemory and I'm back up to 99.25 MB. 15MB of memory was being used just to keep Yahoo loaded in its memory. It can be a lot higher if you have multiple pages open and pages that are more memory intensive. Now just to prove that restarting your phone helps conserve battery, I'll restart my phone because even 99 MB free is low for this phone. It boots back up and go back into FreeMemory and I now have 160.39 MB free. Now you're telling me that the extra 80MB in this simple example of just using Yahoo doesn't affect battery life?

 

[-aggie-]

What I'm saying is when you are on the home screen. It is still keeping that page in it's memory, whether or not it is doing any processing. That is why when you open up Safari the page is already loaded and it does not need to access the web to retrieve it again.

Here's a small test. I have an app called FreeMemory which tells me how much free memory I have available on my phone. Right now I have 99.81 MB free (should be higher, phone probably needs to be restarted, but will still work for an example). This is without any page loaded in Safari. Now I will go into safari and load Yahoo home page. Hit the home button and go back into FreeMemory and it now says I have 84.10 MB free. I now go back into Safari and close out Yahoo. Now that nothing is in Safari, I go back into FreeMemory and I'm back up to 99.25 MB. 15MB of memory was being used just to keep Yahoo loaded in its memory. It can be a lot higher if you have multiple pages open and pages that are more memory intensive. Now just to prove that restarting your phone helps conserve battery, I'll restart my phone because even 99 MB free is low for this phone. It boots back up and go back into FreeMemory and I now have 160.39 MB free. Now you're telling me that the extra 80MB in this simple example of just using Yahoo doesn't affect battery life?

Hmmm....not sure. I wouldn't think RAM would affect the CPU, thus causing battery use. Would be nice to hear from someone who knows how the CPU on the iPhone works. But for a normal computer, just using more RAM would not cause the CPU to heat up, it would be the computer operations that would do that, so again, not sure how your example would cause the battery to be used more.

 

[STEVESKI07]

Hmmm....not sure. I wouldn't think RAM would affect the CPU, thus causing battery use. Would be nice to hear from someone who knows how the CPU on the iPhone works. But for a normal computer, just using more RAM would not cause the CPU to heat up, it would be the computer operations that would do that, so again, not sure how your example would cause the battery to be used more.

Yeah I would like to hear this from someone who knows the iPhone CPU and RAM better because I don't. I'm just going off of my basic knowledge of computer parts, not phone specific. My reasoning is that the more processes you have stored in memory, the less you have available for other tasks, meaning the CPU would have to try harder on other tasks. You're right, if the phone is in standby, I'm not sure if there would be any noticeable loss or any loss at all of battery life no matter how much is stored in memory. I would imagine that the more you have stored in the memory, the harder the battery would work to keep all that info there, although this is just my imagination running wild.

 

[CubeHacker]

I would have to say that I think something is wrong too. I can get on average 5-7 days of usage out of my 3G with about 30 min of talking each day. I've gotten a maximum of 9 hours of talking with 20% battery still remaining as well. Dying after 10 hours of mp3 playback doesn't sound right.

As others have mentioned, it IS possible for the battery to drain prematurely if you are in a very weak signal area (2G or 3G, though 3G is worse). Have you tried switching to 2G to see if the problem persists?

 

[The General]

Yeah I would like to hear this from someone who knows the iPhone CPU and RAM better because I don't. I'm just going off of my basic knowledge of computer parts, not phone specific. My reasoning is that the more processes you have stored in memory, the less you have available for other tasks, meaning the CPU would have to try harder on other tasks. You're right, if the phone is in standby, I'm not sure if there would be any noticeable loss or any loss at all of battery life no matter how much is stored in memory. I would imagine that the more you have stored in the memory, the harder the battery would work to keep all that info there, although this is just my imagination running wild.

Try harder? No. When there's no RAM left to store things, computers use swap space.
http://en.wikipedia.org/wiki/Paging

 

[STEVESKI07]

Try harder? No. When there's no RAM left to store things, computers use swap space.
http://en.wikipedia.org/wiki/Paging

When my memory is running low on my PC, my machine runs slower, which is where I was getting the "trying harder" to complete a task that would normally take much less time. I'm not sure how the swap space works, but I glanced over the first few lines of that link and no matter how CPU's manage it, they still seem to have to do more processing then they would have if there is just plenty of memory available. I'm not an expert on this subject so I may not be 100% right but I know there definitely is some validity in what I'm saying.

PS. The General, can we not start this again? There's no need for bickering back and forth. If you have something worthwhile to input then please do. If you're just trying to pick out small things in someones post that you want to pick on then just go somewhere else.

 

[chr1s60]

Battery life advertised when tested by the manufacturer is always much higher than any person should expect to get. I usually figure to take at least a few hours off most estimates. When a manufacturer tests these batteries they do it with absolute optimal conditions. They test at the perfect temperature for the battery, perfect settings on the phone and everything which is why they get such high numbers. I will conduct this test this weekend to see what kind of results I get. I expect at the most I will get 14-16 hours on iPod.

 

[The General]

PS. The General, can we not start this again? There's no need for bickering back and forth. If you have something worthwhile to input then please do. If you're just trying to pick out small things in someones post that you want to pick on then just go somewhere else.

I didn't even realize it was you. You must just post weird things that need correcting too often.

 

[-aggie-]

When my memory is running low on my PC, my machine runs slower, which is where I was getting the "trying harder" to complete a task that would normally take much less time. I'm not sure how the swap space works, but I glanced over the first few lines of that link and no matter how CPU's manage it, they still seem to have to do more processing then they would have if there is just plenty of memory available. I'm not an expert on this subject so I may not be 100% right but I know there definitely is some validity in what I'm saying.

PS. The General, can we not start this again? There's no need for bickering back and forth. If you have something worthwhile to input then please do. If you're just trying to pick out small things in someones post that you want to pick on then just go somewhere else.

Try to get a little thicker skin. He doesn't seem to be bickering, but just making his points. That's what we do here, isn't it?

I tended to think the same way as the General, but didn't want to say something about how a flash drive works with the CPU, since I'm not sure. For a hard drive, what he said is how it works, which is why I doubted the RAM being a battery intensive issue. But what we need is someone who actually knows.

Edit: Okay, I wrote the above b4 the General responded with the above. You guys both need to cool it!

 

[samcraig]

I think I have pretty decent battery life... but a question for you (see end of my post for the actual question)

Here's some of my stats today:

Unplugged at appx 7:30am
3G, Push, Wifi, Location Services = on
Brightness around 40 percent

One email account which gets pushed from mobile me and ~ 200 emails which I didn't really read since I'm logged into my computer - so I just mass deleted them.

Watched about 30 min of video

Total usage reported: 1 hr 2 minutes; Standby 8hrs 32 min
Battery level: 86% at 4:38
---

Yesterday all same settings and similar usage (but some more video watching, a few phone calls, app downloading/testing and some web surfing) but had about 3.5 hours of usage; standby of 16 hours and ended with a battery level of 49 percent.
----

Here's the question - a few of you are posting that you get 1-2 days + 7-8 hours of usage and based on my usage patterns that seems "in line". We all know it depends on WHAT you are doing with the device so no two use cases are going to be the same anyway. But those tapping out your battery after day 2 of a charge (or partway) - do you prefer to drop to critical or just charge every night?

I had thought it was better to top off each night and refresh the battery every 30 days or so vs tapping it out every cycle.

 

[-aggie-]

SNIP...Here's the question - a few of you are posting that you get 1-2 days + 7-8 hours of usage and based on my usage patterns that seems "in line". We all know it depends on WHAT you are doing with the device so no two use cases are going to be the same anyway. But those tapping out your battery after day 2 of a charge (or partway) - do you prefer to drop to critical or just charge every night?

I had thought it was better to top off each night and refresh the battery every 30 days or so vs tapping it out every cycle.

You want to charge as little as possible, but you shouldn't go to as you call it "critical" or discharge if you can help it. It's good to do that once a month to calibrate the meter, but you want to mininimize charging if you can help it, since there are only a finite amount of charge cycles for these batteries.

 

[abijnk]

Hmmm....not sure. I wouldn't think RAM would affect the CPU, thus causing battery use. Would be nice to hear from someone who knows how the CPU on the iPhone works. But for a normal computer, just using more RAM would not cause the CPU to heat up, it would be the computer operations that would do that, so again, not sure how your example would cause the battery to be used more.

Paging could affect this. If you've got a safari page sitting in RAM doing nothing then the OS might need to do more paging.

 

[samcraig]

You want to charge as little as possible, but you shouldn't go to as you call it "critical" or discharge if you can help it. It's good to do that once a month to calibrate the meter, but you want to mininimize charging if you can help it, since there are only a finite amount of charge cycles for these batteries.

I thought charge cycles = 100 percent charge. So if you use down to 50 Percent on day 1 and then charge and then the same on day 2 the total = 1 charge cycle (50 percent + 50 percent = 100 percent = 1 cycle)

I believe there are several posts/documents explaining this. Am I mistaken? Or is a charge "cycle" just anytime to go to 100 percent from wherever you are battery wise (90 percent or 10 percent)

 

[-aggie-]

Paging could affect this. If you've got a safari page sitting in RAM doing nothing then the OS might need to do more paging.

Correct, but how much that would affect the battery is questionable (for the example he gave of 80 MB).

I thought charge cycles = 100 percent charge. So if you use down to 50 Percent on day 1 and then charge and then the same on day 2 the total = 1 charge cycle (50 percent + 50 percent = 100 percent = 1 cycle)

I believe there are several posts/documents explaining this. Am I mistaken? Or is a charge "cycle" just anytime to go to 100 percent from wherever you are battery wise (90 percent or 10 percent)

You are correct about the cycles. The battery only has a limited amount of these cycles before it won't hold a charge. Reading my earlier post, I guess I didn't write that very clear. Oh well.

 

[Chris Grande]

Paging could affect this. If you've got a safari page sitting in RAM doing nothing then the OS might need to do more paging.

Paging doesn't occur on the iPhone. The iPhone only has physical memory to deal with, there is no virtual memory. On the iPhone when memory gets tight the OS notifies all running applications that things are getting bad. First it is up to the app to deal with this. For example MobileSafari clears all pages from memory then quits, MobileMail just quits, then the OS will force quit running apps if they don't do anything within a reasonable amount of time. If memory runs out the iPhone will restart itself.

 

[-aggie-]

Paging doesn't occur on the iPhone. The iPhone only has physical memory to deal with, there is no virtual memory. On the iPhone when memory gets tight the OS notifies all running applications that things are getting bad. First it is up to the app to deal with this. For example MobileSafari clears all pages from memory then quits, MobileMail just quits, then the OS will force quit running apps if they don't do anything within a reasonable amount of time. If memory runs out the iPhone will restart itself.

So, what are your thoughts on RAM and the battery usage (or how it affects the CPU)?

 

[Chris Grande]

So, what are your thoughts on RAM and the battery usage (or how it affects the CPU)?

Well I could see on the 2G and 3G iPhone it could have some very slight affect since the OS has to do some work when things get constrained as could easily happen on those models and of course the work the OS is doing is highly marginal. The 3GS has so much more room in that sense that it is very rare for a critically low memory situation to occur and when it does it would be mostly likely caused by a 3rd party app running in the foreground which would be using more CPU/Radio/LocationServices/etc anyway. The large power drains on any mobile phone are the cell radios. Low signal or areas on the 3G/Edge line cause the battery to drain faster since the phone constantly tries to reconnect. LocationServices shouldn't have any effect when just on since they are on demand and therefore have to be used by an app.