# Can a Black hole only have negative EM charge?

I understand that Black holes can have EM charge, they can have EM fields around them.

But is that possible that a black hole has more positrons and protons inside it (or that these have more EM charge), then electrons (have EM charge)?

Will in this case the black hole still have a negative EM charge or not?

Question:

1. Can a black hole only have negative EM charge or can it have the opposite too?
• Yes, black holes can have charge, and charge can be negative. – knzhou Sep 7 '18 at 19:04
• @knzhou my question is the opposite charge, can that be too? – Árpád Szendrei Sep 7 '18 at 23:16

The Reissner–Nordström metric for a non-rotating charged black hole [and more generally the Kerr-Newman metric for a rotating charged black hole] only depends on $Q^2$, i.e. the sign of the electric charge $Q$ does not matter for the construction (except of course for the direction of the $E$-field).