Mathews Associates supplies the U.S. government and law enforcement agencies with batteries for unmanned vehicles whether for ground, air, or underwater. Popular styles include the BB-390B/U nickel metal hydride rechargeable battery and lithium ion rechargeable BB-2590/U. Compact chargers for these two popular batteries are also available. Mathews Associates offers “Made in the USA” batteries for other applications, and can custom design and prototype batteries in multiple chemistries.