Just a decade ago, Android phones were infamous for short battery life. Since then, there has been a massive improvement in battery technology. If you’re looking for a phone with long battery life, find one with a battery that has a high milliampere per hour rating, or mAh. This indicates the energy storage of a battery. Smartphones with higher mAh ratings have longer run times. For example, a 4500mAh battery will last longer between charges than a 3000mAh battery.