Battery life of my Acer Aspire A315-51-56GT laptop is 3hrs -3.5hrs when battery saver is on .

Sadhana

battery life of my acer A315-51-56GT is only 3-3.5 hrs when battery saver is on. the hard disk was changed  20 days ago . its battery life used to be 4.5 -5 hrs .also it shuts down when battery falls to 20% without any alert. the problem of  shutting down(at 15% battery) was from the beginning week of purchase. 

MaClane

Good afternoon Sadhana !

There is no "average" value for duration.
Numerous factors will interfere with the duration which mainly depends on how the user is using the machine.

First, understand better about the architecture of a mobile device (in this case a notebook).
Notebook components (mainly processor and video) only achieve maximum performance when plugged into the power outlet.

This time can vary due to many factors: air conditioning in cooler and cooler temperatures, the sum of the applications you have on your machine running, services in the background, among others.

See the following diagram:
OS + Configuration Applications + Services = Requisitions
Requisitions consume resources.
Features are all types of physical memories (HD and storage devices), volatile (RAM and video memories), processors (CPU and GPU) and connections (Wireless, USB, etc.) available on your system.
The more requisitions, the more resources are spent and consequently the energy consumption increases.
So there are several factors of settings that may be undermining the power of your battery.

Just to note, the 2 largest power consumers in a notebook are the screen and the Wireless system.
This Wireless System understands for any request made by your equipment to the connection point (router, modem or access point).
This includes beacons, direct access (such as accessing a website, online videos or an online game) and indirect ones (such as google update, setam services, among others).

Ideally, always use the appliance plugged in and with the power options set to "High Performance".
Using only the battery, the system architecture does not allow maximum machine performance to be achieved.

To improve this duration, you can follow some tips by doing certain processes:

Set the notebook to the power options for economy mode when using only the battery;
Select the option to decrease the brightness on the monitor when in the battery;
Use the appliance in an airy place so that the product does not overheat;
Perform initial cell calibration, as reported in the product manual.
Perform the following procedures:
CALIBRATION AND BATTERY RESET

First, disable Quick Start in the power options and disconnect the notebook from the power outlet.




BATTERY CONTROLLER RESET
Access the device manager and look for the "acpi-compatible control method battery driver" and "Microsoft AC Adapter" and give it up.
Then restart the notebook for Windows to reinstall and remove any errors.




Process to reset the battery

    Disconnect the power adapter.
    Locate the hole to reset the battery in the bottom of the computer.
    He inserted a small clip into the hole. Hold the reset button for 05 seconds.
    Let the computer rest for 5 minutes without power.
    Plug in the power adapter and turn on the system.




External Battery Pack

If your notebook has an external battery, proceed as follows:
1- Unplug the appliance from the mains and then disconnect the battery.
2- Press the power button for thirty seconds, so that the static power is dissipated.
3 - Replace the battery and turn the unit on.

Process for calibrating the battery

For this, you must turn off the device and give a 100% charge.
Then unplug and use the battery until the battery runs out.
Reload it as before.
Repeat the process 3 times so that all cells are fully calibrated.