Ultralife makes specialty batteries and military communications systems. The battery business, which generates roughly 93% of revenue, is the clear core. Ultralife manufactures non-rechargeable lithium batteries in multiple chemistries and form factors, rechargeable lithium-ion and NiMH battery systems, and custom-engineered battery packs for OEMs. Key end markets include military (radios, night vision, targeting devices), medical devices (defibrillators, infusion pumps), oil and gas (downhole drilling, pipeline inspection), and industrial/safety applications. The remaining ~7% of revenue comes from a Communications Systems segment, which designs and manufactures RF amplifiers, power supplies, and integrated systems for military use — this segment is currently unprofitable and declining. Ultralife's core business model is a design-in revenue model: Ultralife works with OEMs during product development to embed its batteries into customer systems, creating sticky, recurring revenue given the high switching costs (requalification in medical and military markets can take years). L3Harris is the largest single customer at 27% of revenue. Ultralife built its battery business through bolt-on acquisitions, most recently buying Electrochem in 2024, a primary lithium cell manufacturer that allows Ultralife to internally supply cells previously sourced externally — primarily for oil and gas packs — improving margins via vertical integration. Growth is pursued through new product development (thin cell batteries, advanced thionyl chloride cells, conformal wearable batteries), further acquisitions, and geographic expansion.