I just bought a new Laptop (Dell Inspiron 15-3521) but it does not keep charge. Before I sleep I charge it to 100% and shut down my laptop. But when I wake up in the morning and switch it on, it says battery low. Is my battery genuine? My batter number is: DSH2016032120053. Made in China. Please I need to know if the problem is the battery or not by checking if it is genuine. Thanks alot.