Complaints from users about the iPhone 4s battery life has prompted an investigation from Apple about the battery drain.

The Guardian reports that some iPhone 4s users have received diagnostic files from Apple that could be sent back to the smartphone manufacturer for analysis. Numerous users have gone online to gripe about their iPhone battery lasting only a few hours even with minimal use.

Now the apparently the battery drain isn't limited to the iPhone 4s but to any iPhone with iOS 5. The battery drain is supposedly caused by overuse of the location tracking installed in the iOS5. Users with iOS 5 installed in their older iPhone 4 have also reported low battery life. The "Setting Time Zone" feature is using mobile phone towers to constantly determine the phone's location and this use of the location tracking drains the battery life.

Users have recommended shutting off the feature which according to some reports have helped. In case this advice doesn't work for you, here are seven more tips to help you conserve your iPhone 4s' battery life.

Tip 1. Turn off iCloud backup. This feature can greatly reduce your iPhone 4s battery because it continually makes backups of your iPhone 4s data. If you want to make back-ups do it manually.

Tip 2. Turn off your Notifications. Turning off Notifications won't mean you won't get new messages, you just won't get visual alerts every time you get new messages. Unless you absolutely need to see notifications about messages, like in some messenger apps, it's better to turn this feature off.

Tip 3. Turn off Location service. Location services can be essential in some apps like Maps but are just battery drains in other apps like Facebook. If you don't need Facebook to see where you are then you can turn off location services for it in Settings.

Tip 4. Toggle your Screen brightness. The Screen can drain a lot from your battery so if you don't need your iPhone to be a beacon, you should immediately turn to Settings and toggle the Brightness. Or better yet always make sure that Auto-Brightness is on.

Tip 5. Don't check the Mail frequently. You can adjust the setting for checking new e-mail in Settings, Mail and Fetch New Data. Set the Fetch New Data to check for new e-mail every hour instead of every 15 minutes. Doing so will save you a lot of battery life.

Tip 6. Turn off Bluetooth. If you don't need to connect with another computer or phone, turn off the Bluetooth function to save battery life.

Tip 7. Set Auto-lock on. Auto-lock is a great batter saver especially if you set to a low time like a minute. Letting the screen turn off when you're not using it is a great way to save battery life.