iPhone 5c Force Restarts

Lets Go straight to my friends Iphone 5c Problem

Wear level is 93 %

when phone is plugged in It charges but the percentage doesnt move (Note when wifi is on While plugged in it charger so fast its jumping like for example 10-19 in just a minute )

When you tried restarting while the phone is plugged in and the percent not moving the percent suddenly change like 65-100 and here goes the problem (After restarting the phone will keep on restarting and flicker ) but it will eventually stops when you let your phone rest .

Whats the problem ?

For me i think its just the battery considering the wear level of it

But i also think u2 ic is also an option

Note my friend uses cheap lightning cable because his cable broked and force to bought cheap one while waiting for his order .

I wanna hear your thoughts and comments thanks guys for your advacned help