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bmwpowere36m3

macrumors 6502
Original poster
Nov 8, 2007
294
0
Since I've had my iPhone 3G, the built-in GPS/MAPS app has always bothered me... from the "pop-up" settings, to battery drain, completely to turning it on/off, etc...

With 2.0.1 & 2.0.2, it was manageable. I always had Location Services OFF to conserve battery power and when I needed it I'd let the prompts in MAPS turn it on. Not bad, except I had to go back to settings and turn it off after I was done using it.

Along came 2.1 and now Apple changed the pop-up prompts, now forcing you to exit MAPS to turn on LS and then re-enter MAPS. Pain in the ass... Along with others I was hoping Apple could devise a protocol that would allow users to have it ON or OFF, however when ON it would only turn on in MAPS and shut-down when exiting MAPS to conserve power.

I decided to run some "tests" on my iPhone to see what was up and to also not the "reduced" battery life from leaving LS ON.

The Setup:
iPhone 3G (2.1) Jailbroken
Cheapo Headphones plugged in (audio-level 4)
BT OFF for all tests, 3G ON for all tests, WIFI OFF, NO Fetch/Push, & Auto Brightness ON ~30%
BossPrefs Battery % Indicator turned on to get accurate readings

The Test:
2hrs long
Playing movie (2hrs) in iPod
LS Turned ON & OFF
Phone rebooted & fully charged before each test

Test 1 Baseline:
LS OFF

In this test I set my timer for 2hrs, turned off LS and just played the movie for 2hrs. After 2 hrs, battery was 77% (left).

Test 2:
LS ON

This test again was 2hrs long. This time I turned on LS, but I DIDN'T enter MAPS or use pin-point. Simply just turned on LS. Again after 2hrs, battery was 78% (left).

Test 3:
LS ON & Pin-Point

In this test I turned on LS, but then entered MAPS and Pin-Pointed my location (achieved the "pin"). Then I pressed the home button (NOT extended to force quit, just pressed) and open iPod and played the movie. After 2hrs, surprisingly, battery was 80% (left).

WOW, is all I can say. The results show the "same" battery usage, thus there is difference in power requirements between the three tests. I will not, I sure you guys know anyways... if your in maps using "pin-point" it definitely consumes much battery power. From this simple test I gather Apple somehow actually answered our cries. It seems to me that no matter the setting (LS), the GPS unit isn't powered unless your in MAPS and "pin-pointed". So as soon as you "exit" MAPS the GPS unit is powered off, thus conserving power.

Another sanity check I preformed and anyone (you as well) is turn ON LS, enter MAPS, and pin-point your location... OK. Now, exit MAPS by tapping the home button and let the phone sit UNTOUCHED for ~10 minutes. Now re-enter MAPS and you'll see that MAPS needs to "RE-pin-point" you. If it was constantly powered (GPS), when you re-entered MAPS your "pin" should have still been there and not needed to be re-acquired.

Damn... that's a lot of writing. Well I'm happy to see this and I guess I'll be leaving my LS ON.
 
Thanks for doing all the work.

Now, if they could just get 3G to not consume so much power, we would be in like flin. :D

It (Battery) has gotten better in 2.1 for sure.
 
Thanks for taking the time to do the tests! I have been leaving mine on all the time since 2.1 came out and haven't noticed any difference. Your tests prove that. Thanks again.
 
what's the point of having LS on if you're watching a movie or not using the GPS? But thank you for the experiments.
 
if this is true, this is wonderful. i havent even turned my location services on since the update because i know how it sucks power. maybe now i'll actually turn it on and see for myself. :D
 
what's the point of having LS on if you're watching a movie or not using the GPS? But thank you for the experiments.

The point of playing the same movie was just to drain the battery, at the same time if LS/GPS would be as well. If I just let the phone sit there it would take a while for the battery to drain. Presumably the GPS would have been sucking power in the background anyway.

The tests show you can just leave the LS ON and not have to switch it ON & OFF to conserve battery power.
 
The point of playing the same movie was just to drain the battery, at the same time if LS/GPS would be as well. If I just let the phone sit there it would take a while for the battery to drain. Presumably the GPS would have been sucking power in the background anyway.

The tests show you can just leave the LS ON and not have to switch it ON & OFF to conserve battery power.

This is very good to know, thanks :)
 
what's the point of having LS on if you're watching a movie or not using the GPS? But thank you for the experiments.
The point is that it doesn't use any battery unless you are IN the maps application, so now, you don't have to manually turn it on or off.

Just leave it on all the time.
 
The point is that it doesn't use any battery unless you are IN the maps application, so now, you don't have to manually turn it on or off.

Just leave it on all the time.

Yah I was under that impression as well, I've never bothered to turn off Location Services, but rather whenever I'm prompted in an app to use it, I just say no, and I think that generates the same results as shutting the service off entirely (save the tiny bit of juice used to bring up the prompt message).
 
this may be an extremely nooby question, but how do you find out the exact percentage left on your battery? I can't find this anywhere on the phone
 
this may be an extremely nooby question, but how do you find out the exact percentage left on your battery? I can't find this anywhere on the phone

His phone is Jailbroken and therefore can run several unofficial, third-party apps. One of which is a program that displays exact battery remaining via percentage.
 
this may be an extremely nooby question, but how do you find out the exact percentage left on your battery? I can't find this anywhere on the phone

Jailbroken iPhone (Pwnage) and app is called BossPrefs, inside which there is a setting to see a numeric battery display.
 
I went to the NE (New York and Boston) right after the update Friday and the GPS seemed to not operate as well as I remember pre 2.1. Most of the time I was only getting the triangulation, but not the blue dot. Now that I'm back in Miami it seems to be working well again so I'm thinking it just works better in Miami vs the NE?
 
Hasn't it always been like this?

I mean, it absolutely makes no sense if the GPS was active all the time before 2.1. No way they programmed it that way.
The battery sucking problem is just you making something up in your mind that LS sucks battery. It only does that when it's active in an application, not when the phone is idle or on stand-by.
 
Hasn't it always been like this?

I mean, it absolutely makes no sense if the GPS was active all the time before 2.1. No way they programmed it that way.
The battery sucking problem is just you making something up in your mind that LS sucks battery. It only does that when it's active in an application, not when the phone is idle or on stand-by.

:confused:, While I personally never stated that GPS always drained battery power, it was constantly publicized here on MacRumors and by turning OFF LS you'd be saving battery power.

I just assumed it was the case, in pre-2.1 firmware versions. I just set to discover what was happening in 2.1. I do remember though that pre-2.1, it seemed that the GPS was always tracking you when you exiting MAPS. Now in 2.1 it needs to re-acquire you after you've exited MAPS.
 
Just chiming in; I noticed the same thing over the weekend after finally turning LS back on. Leaving it on has not adversely affected my battery life, like it used to before. Definitely a good bug fix!
 
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