I have two heads
They never come near
I've many friends, whose death is clear
The lucky ones can live again and again
When I die I'm replaced by a twin.
What am I?
Hint:
I'm used nearly every day, but often ignored
I am a
Battery
I have two heads They never come near
Two ends of a battery
I've many friends, whose death is clear
There are many, many dead batteries around
The lucky ones can live again and again
Rechargable batteries
When I die I'm replaced by a twin.
If one battery dies, you buy a new one (same type) and replace it.
lucky ones can live again and again
may have been the line that made me think of the answer.
$\endgroup$
A Pencil
I have two heads
They never come near
Point and Eraser at opposing ends
I've many friends, whose death is clear
Broken, dull, or sharpened to an unusable length
The lucky ones can live again and again
Can be sharpened again and again. Alternatively, mechanical pencils should be essentially infinitely reusable
When I die I'm replaced by a twin.
Pencils are essentially identical, and you'll likely replace one with another.
I think the answer is batteries.
I have two heads
The poles of the battery, used to power the device the get plugged into.
They never come near
The battery is a fixed shape and so the two heads of a single battery do not touch.
I've many friends whose death is clear
Batteries are said to "die." And you can tell they have died when the device you are using loses power. Also, some batteries let you gauge the power left in them by holding down certain points.
The lucky ones can live again and again
Rechargeable batteries escape the fate of their normal brethren.
When I die I'm replaced by a twin.
Normally you don't mix battery types, so you replace like for like. Also people normally buy a single type at a time.
Hint:
I am used nearly every day but often ignored.
You don't give batteries a thought until your device stops working. So you often ignore them.
Edit: Too slow on mobile, someone beat me to it.