Beacon Power Corp. said Tuesday it had reached a deal to sell up to $25 million worth of its shares to a Chicago-based investment fund over the next 26 months. The Tyngsboro, Mass.-based company, which develops energy-storage and management technologies, announced it had already sold 1.5 million shares, for $500,000, to Aspire Capital Fund, LLC. Aspire has committed to buy another $24.5 million worth of common stock under the agreement, according to Beacon Power. The deal allows Beacon to direct Aspire to buy up to 400,000 Beacon shares on any given day at a purchase price of at least 34 cents per share, so long as the closing share price was above 25 cents. â¿¿Beacon Power will control the timing and amount of any sales of Beacon common stock to Aspire Capital and will always know the sale price before giving notice to Aspire Capital to buy any shares,â¿ Beacon said in its announcement. Beacon Power (Nasdaq: BCON) said proceeds from the sales of the common stock will be used for general corporate purposes and working capital. The stock closed at 32 cents on Friday, and the companyâ¿¿s total market capitalization was $58.5 million. The share price had lost more than half its value in the past year, falling from 87 cents a share on July 2, 2009. In the first quarter of this year, the company booked a $5.5 million net loss and saw its cash position slip by 23 percent despite reporting advances for hiring and for the companyâ¿¿s so-called flywheel energy-storage systems. Among those highlights was accelerated flywheel production for a planned 20 megawatt energy-frequency regulation facility in Stephentown, N.Y. That production was expected to result in 50 new jobs. In May, the company announced $2 million commitment from the New York State Energy Research and Development Authority to help fund the Stephentown plant.