Here's how you can easily switch between 3G and 4G networks. Using a 3G network might help save some battery power on your Android phone. 1. Open the Settings menu. 2. Go to Network Mode. 3. You can opt to use CDMA only (3G) or CDMA and LTE (3G and 4G). If your 4G network isn't that great then consider switching down to 3G. You'll still get a good data speed, but your Android phone's battery might last a bit longer.
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Android Tips | CS Monitor