Strange battery problem

[Abhinv]

Hey! I have a Moto G3 phone and after 3yrs the problem starts that is my phone is shutting down initially between 0-15% and after sometime it starts shutting off at any % say 21, 30, 35 and when I plugged in charge it starts from the % at which it switched off then I did factory reset after which the phone battery behaving strange say it drops from 15% to 5% in seconds and then stuck at 1% for an hour.
What is the actual problem my phone have software or hardware?
Thanks in advance

 

[lvt]

From what I've read, phone battery loses 15-20% of its capacity per year throught repeated charging cycles. So after 3 years your phone's battery might only keep 60% its original capacity at best. When the battery goes bad it could be hard for the charging circuit to keep accurate track of the battery condition. Weird things can happen for example battery overheating, phone suddenly turns off...

 

[lvt]

Replacing the battery is your only option.

 

[Abhinv]

Means this problem is not due to any software issues?

 

[svim]

While there could be a software issue, with a three year old phone it's a lot more likely the battery is failing. Especially if you've been regularly running it down to single digit capacity. That's generally not recommended as it tends to shorten a smartphone battery's overall life. This article from BatteryUniversity is a good read on this issue (pay special attention to 'sweet zone'):
https://batteryuniversity.com/learn/article/premature_voltage_cut_off
Of course most of us have other issues in our lives to focus just on keeping our phone batteries charged within such specific numbers, but it is something to at least make note of especially when it involves phones without user-replaceable batteries. (like your Moto G3). But if you're comfortable with the tools necessary to tear down a smartphone, iFixit has a nice step-by-step guide on replacing your G3 battery:
https://www.ifixit.com/Guide/Motorola+Moto+G3+Battery+Replacement/106936

 

[Abhinv]

Thanks
By the way if there is any software issue then factory reset would not solve it, in yhit case

 

[Abhinv]

This*