Has anyone calculated the charge/mass ratio of an extremal black hole?

The electron has been defined as a gravitationally confined entity with some of the properties predicted for an extremal black hole.

The known electron angular momentum value (h/4pi) implies a radus value (Le/4pi) where (Le) is the electron Compton wavelength.

angular momentum = (h/Le)(Le/4pi) = h/4pi

The only known way that this angular momentum can exist with a particle (electron) that is far smaller than the radius (Le/4pi) requires gravitational collapse (with conserved angular momentum).

With gravitational collapse, the electron photon sphere radius or photon orbit radius will be 3Gm/c^2 meters which is too small to measure but larger than zero or a point.

We find that the ratio of the length 4pi(3Gm/c^2) to the electron Compton wavelength is equal to (3/2)^1/2 (Planck time) divided by (2pi seconds).

4pi(3Gm/c^2)/(Le) = (3/2)^1/2 (time P)/2pi sec)

From this relationship, electron mass equations are defined.

mass = (h/4pi c)(c/3pi hG)^1/4

mass = (Le/4pi)^3 (1/2pi)^2 (1/3G)

The gravitationally collapsed particle (electron) is required to be extremal because it is known to be stable.

Don Stevens