Why i need to replace my iphone battery every time it died?

Few months ago my iphone 5 was out of battery and when i try tried to turn it on the screen didn't move
I've tried everything to turn it on and nothing worked then i replace the battery and since then each time the battery died i need to replace it or to unplug it for a few minutes and then but it back and it will work.
Someone told me that something is wrong with the power management in the motherboard that when the battery died it doesn't allowed the battery to charge again
And when i charge it, it reach 100 but never show me fully charged icon
Till now no one knew what is wrong with it.
Please help what could be the problem
And please don't till me that i should reset it or upgrade it or change the cable

Have the apple store look at it.

Brother,

See here is not a motherboard problem that is just a CPU Problem that is using a huge power in your iphone 5 mobile. Just go to any repair shop of mobile and said to engineer to just give the heat 5-6 power on CPU chip problem would be solved.

You must be after the heat then take into the some cover after two hour check it.