For quite some time now, Samsung Galaxy A3 (2016) users have been reporting issues with battery charging. Specifically, they say their device's battery doesn't charge beyond around 85%. Steps like clearing cache, swapping chargers, charging in safe mode, and even a full factory reset prove to be of no help. Reports say there's a bug in the device's Nougat build that's causing this issue. While the South Korean company hasn't officially said anything on it, some of those affected say they've been informed that a fix is incoming. A specific time-frame for the arrival, however, isn't...
Source: http://www.gsmarena.com/samsung_galaxy_a3_2016_users_are_reporting_battery_charging_problems-news-27409.php