Photoelectic effect and units

[prehisto]

Homework Statement

HI, I have this photoelectric effect problem, it is not so difficult but when i got to the units and red about it , i got confused.
The Problem : Photo-electrons are completely hold up by electric potential with potential of 3V. The work function is given. I have to calculate the incident light frequency.

Homework Equations

The Attempt at a Solution

So the equation is
E_max=hf_inc-φ

And the units are
[V]=[J]-[J]
This does not work. So I thought let's convert them to eV which is possible for [J].
But when I start to think about the V -> eV its gets confusing because V are not measurement of energy but eV are.

So what do you think guys, can I just do the conversion from [v] to [ev] by multiplying V by e or it is wrong?

 

[Bandersnatch]

Emax does not denote the stopping potential, but the kinetic energy of a photoelectron. You need to find the relationship between electric potential and energy of a charge in a field.