Quick Question

Why do you think that it stays connected?

You don't know why you think it is connected to wi-fi when it is asleep?

Then how do you know that it is connected?

My iPod Touch 2G has considerably worse battery life since I upgraded to IOS 4.2.1. It clearly wakes up periodically (or stays connected, I don't know which) to, IMO, be aware of incoming Notifications. Try turing OFF Notifications for all apps (in Settings) and see if your battery life improves.

Enabling Airplane Mode turns off both WiFi and Bluetooth, saving even more battery power.

I have been doing some testing on my WiFi at home.

I have several iPod Touches which includes a 2nd and 4th generation iPod Touch.

*You can determine if your iPod Touch is connected to your WiFi by using the Airport Utility.*
*Look under "Wireless Clients" and you will see who is connected at that time.*

Here are some of my findings between the two models all running iOS 4.2.1.

When both generations are connected to a computer or charger, the WiFi will always stay connected whether they go in sleep mode or not.

If I disconnect the 2nd generation from the computer or charger, it will automatically disconnect from the WiFi within about 10 or 15 seconds.
The 4th generation will NOT. It stays connected to WiFi.

I have tested this with and without "Notifications" on and off and doesn't seem to make a difference but we all might have different apps that ask different things of the WiFi...

The only way I can get the 4th generation to disconnect from WiFi is:
1. Turn if off using the Power button
2. Put it in Airplane mode

I know many people are reporting short battery life with the 4th generation and it seems everyone's varies. Here are my results.
My 4th generation last for 3 or 4 days with the WiFi remaining connected.
My 2nd generation last many more days as it automatically disconnects itself from WiFi when it goes to sleep.

Anyone else have any other findings they have done?

Reset Network Settings seems to help many people. It is under Settings---->General----->Reset------>Reset Network Setting.

It will reset all of your previous network settings so if you have a password for your network you will have to re-enter it. This worked on my 2nd Gen ipod. The battery life was terrible once I went from 3.1.3 to 4.2.1. I read about this fix and so far the battery is much better, still not as good as with 3.1.3 but close. HTH

Hey, Joe Kriz.

My experience with my 2G iPod Touch (IOS 4.2.1) is that it stays connected to my Time Capsule *all the time* unless I put it into Airplane Mode or turn off WiFi, regardless of battery or docked power. It didn't occur to me to use the Airport Utility to check on it until you suggested it here. It also made no difference if I turned Notifications Off either. My bad for passing along that idea.

I have not (yet) tried the Reset Network Settings because I didn't really want to have to reenter the pass phrases for the different networks I regularly use. Time to do it, I guess.

Hi Bruce,

I originally had a problem with one of my two 2nd generation iPod Touches.
The battery was draining much quicker than it used to and I think it was due to the WiFi.

All I had to do was to shut the iPod Touch down using the power switch and slider.
After that, the battery was fine and then it disconnected from the WiFi in about 10 seconds after it went in sleep mode.

It's worth a try.
Otherwise, maybe resetting the WiFi might help although it wasn't necessary for me.
Both of my 2nd generation iPod Touches disconnect from the WiFi almost immediately after going in sleep mode.
The 4th generation will not. I think the 4th generation is designed this way as far as I have found.

No problem on the Notifications. As I mentioned above, we all have different apps and some might call on WiFi more than others.
At least you know that isn't the problem for you.

Good Luck and let us know.

No joy for me with the Power switch and slider. I tried it again for the umpty ninth time and it still makes no difference. I will try the Reset Network Settings tip tomorrow after I perform some additional testing on another issue I am having with xfinitywifi hot spots. I don't want to change multiple things at once and risk further obfuscating the problem.

This afternoon I initiated the Settings app > General > Reset > Reset Network Settings in the hope that doing so would permit my iPod Touch 2G to turn off WiFi when it goes to sleep. Alas, no joy.

It would be helpful to know if WiFi is supposed to behave this way or not under IOS 4.2.1, and whether or not it behaves differently across iPod Touch 2G, 3G, 4G

Joe Kriz 2G iPod Touch disconnects from WiFi when it goes to sleep, but his 4G stay connected.

We need more data points.

So I also did an iPod Reset using the On/Off Wake/Sleep key + Home key and holding them for 10 seconds. This made no difference at all. My iPod Touch continues to stay connected to WiFi when it is sleeping.

Bruce,

It would be interesting to know what others find.

I can confirm that both of my iPod Touch 2nd generation models disconnect completely from the WiFi.
Meaning, they completely disappear from Airport Utility list of "Wireless Clients" when they go to sleep which takes about 10 to 15 seconds or possibly more if you have your sleep feature set for more minutes.

This is one of my 2nd generation iPod Touch info when connected to Airport Extreme and viewing it in the Airport Utility list of Wireless Clients.
00:XX:XX:XX:XX:DB -48 -84 54 802.11b/g

When the Touch goes to sleep, the above info just disappears from the list and is no longer connected.
When I wake it up, the above info reappears in Airport Utility list of Wireless Clients...

I asked my son to check how his iPod Touch 3G acts. His is running IOS 4.0, but he tells me that Airport Utility reports that his iPod remains connected to his AEBS when his iPod is in Sleep mode. He has to use the On/Off Wake/Sleep switch and the slider to turn it all the way off before it disappears from the Airport Utility list of wireless clients.

So, based on this admittedly small sample, I'm thinking it must be intentional for WiFi to remain on but that older devices such as my iPod Touch 2G which are not as power efficient suffer reduced battery life as a result.

This does not explain Joe Kriz's observation that both of his 2G iPod Touches disconnect.

Comments I found on other threads in Discussions imply that persistent WiFi connections during Sleep are a feature of IOS 4.x. I don't remember reading this in any Apple documentation, but I may have missed it. Persistent WiFi would enable lots of things to be initiated during Sleep, including the Find iPhone feature.

In working on my battery drain problem, I found postings that mentioned persistent connections to the iTunes Store being a problem. So, last night in Settings > Store I explicitly signed out of the iTunes Store.

For good measure, I turned of Notifications as well.

This morning, my iPod Touch 2G still had over 90% battery, much better than before I took these actions.

As a side benefit, I discovered that once my AppleID was signed out of the Store, I could now complete the login to Game Center, something that had failed in an endless loop of attempting to create an account every time I tried it since upgrading to IOS 4.2.1

So, tonight I will turn Notifications back on and see what the effect is, if any.