Good day sir i have bougth my acer 5315 since when i bougth it is not charging so whats the problem with the battery

There's a possibility that your battery is bad. and if you want to check that you have a known good ac adapter. here are the steps that you can try.

1. turn off the laptop. (shut it down properly).
2. remove the battery and disconnect the charger.
3. plug in the charger without the battery.
4. power on the laptop.

note: if it comes on normally. it means, that your charger works fine. from that point, you could isolate if it's a battery or a charger issue.

Good luck,

Ryan