Maxwell Technologies (Nasdaq: MXWL) today reported revenue of $26.6m for its first quarter ended 31 March 2010, up 19% over the $22.5m recorded in the same
period in 2009. Operating loss for the first quarter 2010 was $1.6m, compared with an operating loss of
$1.8m in the same period last year. Net income for Q1 2010 was $1.2m or $0.05 per diluted share,
compared with a net loss of $3m, or $0.13 per diluted share, in Q1 2009. The net income/loss
comparison is affected by a non-cash gain of $3.2m, or $0.12 per diluted share, in Q1 2010 versus a non-cash
loss of $0.6m, or $0.03 per diluted share, in Q1 2009, based on the quarterly valuation of conversion
features and warrants associated with convertible debentures issued in 2005.

Q1 2010 BOOSTCAP® ultracapacitor revenue increased by 79%, to $13.8m, compared with $7.7m for the same period last year. Sales of high-voltage capacitor and microelectronics products totalled
$12.8m for Q1 2010, down 13% from the $14.7m recorded in Q1 2009.

“Ultracapacitor sales growth continues to be driven primarily by increasing demand for energy storage and
power delivery systems for hybrid transit buses and wind turbines, and we are now seeing a more meaningful
contribution from various backup power applications,” said David Schramm, Maxwell’s president and chief
executive officer. “Increasing volume and improving efficiency enabled the company to generate cash from
operations in Q1 for the third time in the past four quarters.

“Growing environmental consciousness at the consumer level and government mandates and subsidies for
reduced emission public transit, commercial and passenger vehicles and emission-free renewable energy from
wind turbines are driving increasing demand for efficient, reliable, cost-effective ultracapacitor-powered
solutions,” Schramm added. “Based on strong current bookings and order activity, we expect sequential
ultracapacitor sales growth in the second quarter, and that higher volume, along with improving overall gross
margins, should move us closer to our goal of profitability at the operating income line.”

Cash and restricted cash totalled $38.1m as of 31 March 2010, compared with $37.6m as of
31 December 2009. Q1 2010 gross margin was 38%, compared with 31% in Q1 2009 and 34% in
Q4 2009. Operating expenses totalled approximately $11.8m, or 44% of revenue in Q1 2010, compared
with $8.8m, or 39% of revenue in Q1 2009. Complete financial statements and management’s
discussion and analysis of financial condition and results of operations will be available with the filing of
the company’s quarterly report on Form 10-Q with the Securities & Exchange Commission.

As previously disclosed, the company has been conducting an inquiry into the nature of payments made to a
former independent sales agent in China associated with sales of high-voltage capacitor products produced by
Maxwell’s Swiss subsidiary. The company has been voluntarily sharing information with the Securities & Exchange Commission and the Department of Justice, and discussions with those authorities are ongoing.

For accounting purposes, under US generally accepted accounting principles (GAAP), based on the
company’s estimate of a potential settlement range of $9.3mto $20m, the company recorded an
accrual of $9.3m in Q4 2009.
Management conducted a conference call and simultaneous webcast to discuss first quarter financial results
and the future outlook. The archived replay may be accessed at the company’s website.