LOCAL listed battery developer ZBB Energy has announced that it has entered into a letter of understanding agreement with US-based Wharton Equity Partners for a $US5 million strategic investment. ZBB chairman Richard Payne says the company is currently developing a magnesium battery that will be ready for commercial application in about two years. Wharton holds a 12 per cent interest in a company called Idea One, which is involved in the development of alternative energy products through its Israeli-based subsidiary Advanced Technology Upgrading. Once finalised, the deal will give ZBB direct access to leading electro-chemical battery researcher Profesor Doron Aurbach, based in Israel. Wharton will hold shares and options in ZBB based on an issue price of 50 cents each.