Even someone had said FW3.1 will update about battery, but don't expect too much on it. It might nothing different after upgrade.

The battery of i3gs basically is same with i3g. However, due to upgrade hardware on i3gs, and it need more energy to support those new hardware spec, so it is normal battery drain faster than i3g. You can tahan until 2 days, actually not bad already.

i disable all the thing regarding notification ,3g/edge, email push and sort of thing regarding battery....including off my wifi when nok using it....thats why my i3gs can stand longer. hehehe

Whether the battery is the same or not, should not be a concern for customers like us. They have marketed the battery life everywhere and now it seems to fall so short of it. I'm quite disappointed by Apple. You may be right that due to the upgrade of hardware, the battery might drain faster, but let's not forget the OS is also upgraded, which can also manage power more efficiently and effectively. Just like Windows and Mac, why is it both machines have similar hardware but Mac can run it better and with less problems?

I have been using my phone 1yr+9months.. the battery now only can last for 1day with normal use, like answer call, sms. No wifi, no music .. terrible.

my 3GS can last for 3 - 4 days. Normal call & sms usage. A bit of wifi usage. That's all.

woah ~
after 1 year , and it only able to use for 1 day ?

dats very unbelievable. coz ive never seen any 3gs go beyond 2 days unless ur fone is on standby mode for bout 90% of the time. i realise iphone 3gs goes kaput after 6hrs of usage. haha. not counting standby time.

FYI i have some startling discoveries on my iphone 3g OS 3.0.

Battery life goes from 100% to 0 in 12 hours with no wi fi usage some calls and sms on this settings:-

Push - off
3g - off
wi fi - off
location services - off

But this is my third day with no wi fi usage and just sms and calls with this settings

push - on
3g - off
wi fi- on
location services - on

Now i really wonder why. *shrugs*

Have you tried restoring it as a "new" phone?

I tried that, solved my problems. Well not solved, but allows my iPhone to live up to 2 days without charging. But now that I'm playing games on it....

wow...pretty good though....mind to share ur setting.....

i found out this thread...can help iphone/ipod user to make their iphone free more memory and a bit less drain the battery...i have try it....do it at ur risk k...because u need to play with plist files...so follow the intrustion properly.
http://www.ipodtouchfans.com/forums/showthread.php?t=224341

This post has been edited by kebeckham7: Aug 27 2009, 03:28 PM

wow.. tat's really good.... how often do u call n sms in a day??

tried everything but cant get past half a day at most 1 day without calls and sms with my old settings. with new settings i can easily get 2 days minimum.

maybe ur 3gs is defect unit.. my 3gs battery can last long for 2 days standby and 7hrs of usage(games, app, safari+3G, wifi, mail, map+3G, sms, call). My standby time 1% batt = 2.5-3hrs..

This is my initial battery charging..

#1 - Buy the iPhone 3G. Do not use the iPhone 3G.
#2 - Initially charge your iPhone for 3 hours. I've read conflicting statements about this. To be safe, don't use your phone before letting it charge for 3 hours. Also, use your wall charger (avoid the computer charger).
#3 - Now it's time to calibrate your battery indicator. Let the iPhone's battery fully drain. Keep the iPhone off for five hours once drained, then fully charge your battery. Allow the battery to rest in the fully charged state for two hours. You may use your iPhone during this time as long as the iPhone is plugged in.
#4 - Repeat step #3 a maximum of three times if you feel your battery indicator is inaccurate.

copy paste from this LINK

for Everyday Charging i always let the 3gs batt fully drain by it self.. (standby at 5% batt and let the phone fully drain, at this point u can see the % will goes up and down and goes up again..) and i use wall charger..

i am using OS 3.01

This post has been edited by afizudin: Aug 27 2009, 03:30 PM

As for mine, it can last for 3 days and a few hours max with 4 hours plus of usage.

Ermm.. Can I ask whether it's bad for the iPhone's battery to charge overnight? Cause I often do that and am wondering whether it would affect the battery life in the future?

don't think it's a problem. the phone will use power str8 from the electric socket once the battery is full. there's no risk of overcharging.

Update:

I found that if the signal is stronger, the battery life improves dramatically. I switched out my sim card today to a different carrier and my battery life was back to normal.

That's not likely. Even with Airplane mode on for the whole time, it still drains at the same rate with the same usage.

It is plausible because the phone does not have to 'exert' to maintain connection and thus conserve some energy although I might add that the difference should not be as dramatic as you described it to be.

thats some quote there. mind sharing ur setting & charging pattern. thx