My take on this is somewhere around 4 months to 8 months minimum. I myself studied for over a year, but that was because my exam was pushed back twice. I started studying around November 2019, and I was originally supposed to take the exam on April 2020. But that got pushed back due to CoViD. Looking back though, I don't think I would've been well-prepared on April 2020 as opposed to when I finally took my exam just 2 weeks ago.
We highly recommend Zach Stone's Electrical PE Review course. I believe he is currently doing a live weekly course, and his website also has Premium Course notes. It is a monthly subscription, I myself was fine with using just 2 months.
Another good prep is Engineering Pro Guides.
We also recommend doing as many practice exam problems as you can, to better drill the concepts needed for the exam into your head. Here is the list of practice exams that I used, and below is my opinionated list:
JUST BEGINNING TO PREPARE AND STUDY FOR EXAM:
- NCEES Practice Exam
- A.S. Graffeo Exam
- Complex Imaginary Exam: 4 sets of problems
- Spin-Up PE Exam: 5 sets of problems
MIDWAY STUDYING FOR EXAM:
- PPI Practice Exams: 2 sets of problems
- Shorebrook Exam
HARDER DIFFICULTY PRACTICE EXAMS:
- Electrical PE Review Practice Exam
- Engineering Pro Guides Full and Final Exams
- Cram for PE Power Exam Volumes 1 thru 4