A: If your laptop requires frequent charging and takes longer than expected to get to 100% capacity, it is time for battery replacement.
Also, if your device reaches the power-off stage soon after removing the power adapter, that is another indicator that you should change the battery.
A: No, they can not. Since as soon as the battery reaches its 100% charging capacity, the laptops stop charging further and start using power from the AC adapter.
A: With time, every rechargeable battery gets worn out. Youll notice this when the run time decreases, usually after 18 to 20 months. The battery life also depends on how vigorously you use your laptop.