@titanoman is on the right track here. The EVO 3D seems to have issues with latency getting the WiFi radio reconnected after it goes to sleep, which (I think) is the problem you guys are seeing.
By default, Android sets the WiFi to sleep whenever the screen turns off, which sounds like a good idea, but doesn't actually get you the extra battery you would think. This is because the phone *wants* an internet connection so, as soon as the WiFi cuts out, the 3G tries to come back on.
This is generally a good setting to change on any phone if you spend most of your day around WiFi access points, since the WiFi radio uses significantly less juice than the 3G radio. Here's how you do it:
- From the home screen, press the "Menu" softkey and select "Settings" from the popup menu.
- Select "Wireless & Networks" from your settings screen.
- Turn on WiFi (if it isn't already) and then click "Wi-Fi Settings".
- Now, hit the "Menu" softkey again and you'll get a popup menu with an "Advanced" button.
- After hitting "Advanced" you'll go to the screen were you can see your current WiFi IP address and connection info. At the top is an option called "Wi-Fi Sleep Policy". Click that.
- The options are as follows:
- After 15 min: WiFi shuts down after you haven't been transmitting or receiving data for 15 minutes.
- Never when plugged in: WiFi will always stay on if the phone is plugged in, otherwise the 15 minute policy applies.
- Never: Exactly how it sounds. WiFi will never sleep and will always remain connected.
- There's also an option here called "Best Wi-Fi Performance", but the phone warns that it could drain the battery faster. I honestly don't know exactly what that one does.
It's important to note, that this
could have a negative impact on your battery depending on your use. I
strongly recommend going to the basic WiFi settings screen and
disabling the "Network notification" option, since this will cause your phone to
constantly scan for an open WiFi when you're not connected. And, since we've just set your WiFi radio to never go to sleep, that could be very bad
Also, I would recommend turning off the WiFi radio when you know you're not going to be around WiFi for a while. There's a ton of widgets out there that make this super easy, even if you don't like the ones included with Sense. Personally, I use the Power Control Plus widget, cause I like being able to configure it with exactly with options I want.
http://market.android.com/details?id=com.siriusapplications.eclairwidgets
Good luck, guys. I hope this helps.