At this point I own the idea(worth=$0) and 100% equity. And without a technical partner I have no beta product. He's open to the idea of equity in the company.
I'm a business-minded, action-oriented guy. I feel I'm good at team building, marketing, selling, partnerships & strategy. The real business side of things.
He knows the technical side. What is fair 15%? 45%?
You need him or else you do not have a product. No product means no company.
No reasonable developer would take anything less than this...If they're going to be putting their energy into developing your product for the next 1-3 years (minimum) then you need to split the equity with them equally.