Why is my phone's battery draining automatically? I am using a Samsung Galaxy Core prime for about 3 years. The problem is that firstly, it gets charged very slowly (takes 7-8 hours to get fully charged) after that battery backup is fine,  nothing unusual happens. But suppose if I charged my phone up to 65% at 9pm and when I see my phone in morning it automatically gets reduced to 32% or when at night it is 27% in morning it will be only 2%. What is happening? Will battery replacement be the solution?
First, it may sound redundant, but restart your phone.

After restarting if the issue persists then do the following:

So, to diagnose the issue with your battery, first you need to find out if there is an app running in the background which is draining the battery. To check this visit this site:


  In all versions of Android, hit Settings > Device > Battery or Settings > Power > Battery Use to see a list of all apps and how much battery power they're using. If an app you don't use often seems to take up a disproportionate amount of power, consider uninstalling it.
  On Android 7, here you can also see how much “Cell standby” or “Mobile standby” is eating up – this is the amount of power your phone gobbles up while not being used. 


After follwing the above instructions, if your battery is still draining I would take it to a service store to get the battery tested and then you can find out if you need a battery replacement or the issue lies somewhere else within the phone hardware or software.

Sometimes a dead giveaway for a faulty battery is that as soon as you plug the phone in for charging, the battery percentage "jumps" for example from 6% to 25%. If this is occurring, you for sure need a new battery.