why is my phon shutting down suddenly?

[mohammad pak]

My phon is Huawei g700 ,and it's 4 years old.details of problem: 1)when i am using phon it some times suddenly shuts down.
2)When i try to turn it back on , i must push the power bottom several times.
3)when turns on, the percentage some times is same as the shut down time, and often is 1 or 3 %.
4) it takes too much time to full charge.
5)when reaches full it's battery percentage downs from 100 to 50 as fast as possible.
6)When it shows a percentage, it is not true.because i use a voltmeter.
7)When i plug in the charger , the huawei lego shown several times and the the vibrator turns on and off without the phon turn on.
8)the battery percentage goes fast to low.

 

[Laura Knotek]

Welcome to Android Central.

Is this the same battery you've had for already 4 years? Most likely the battery is no longer good. You'll need to get a new battery or get a new phone.