3. Meizu MX5 smartphone: The processor is Mediatek Helio X10 and the RAM is 3 GB. The Helio X10 is known for its finely balanced power consumption, which makes the MX5 run smoothly and save power at the same time. However, on long usage—such as voice calls over 30 minutes, playing games, using multiple applications—the MX5 starts heating up. At times, it can be annoying. While the battery is 3150 mAH, there are so many functions and features in the phone that the battery doesn’t last more than a day.