Maxwell Technologies Inc., a San Diego maker of ultracapacitors and energy storage solutions, said Aug. 13 that it closed a public stock offering of 8,580,000 shares at $3.25 per share.

Maxwell (Nasdaq: MXWL) received total net proceeds of $22.9 million after deducting underwriting discounts, commissions and estimated expenses. The business said it plans to use the funds for general corporate purposes.

Barclays acted as sole book-running manager and Roth Capital Partners acted as co-manager for the offering.

Maxwell shares closed the trading day Aug. 16 at $3.66. Their 52-week range was $6.61 to $3.24.