All black holes even the smallest balllightnings are also dark matter and have a negative charge as outside shell and positive charged at the inside globular shell.
The Magic of the New Electric Dark Matter Black Hole on Earth and Space..
see http://vixra.org/pdf/1707.0224v4.pdf
and
https://phys.org/news/2018-05-dark-electric.html
and
https://bigbang-entanglement.blogspot.com/2016/03/the-quantum-fff-theory-function-follows.html