Bren-Tronics

Bren-Tronics was started in 1973 in Commack, New York by Leo Brenna, an Army veteran of the Vietnam era, with a narrow brief that has not really changed since: make batteries for jobs where a dead cell means a failed mission. The company began in primary batteries, moved to rechargeables in the 1980s and became one of the early volume suppliers of nickel cadmium packs to the US military after Operation Desert Storm made the logistics case for rechargeable power obvious. EnerSys acquired the company in an all-cash deal worth 208 million dollars, announced in May 2024 and closed that July. At the time of the deal Bren-Tronics had about 280 staff across the United States, France and the United Kingdom and annual sales near 100 million dollars.

The best known product is the BB-2590/U, the standard rechargeable battery for a long list of American and allied military radios, electro-optics and portable electronics. Bren-Tronics has shipped more than a million of them. The current family covers several energy points and environmental variants, including a 298 watt-hour version, a 251 watt-hour version, a 294 watt-hour high temperature version and a 216 watt-hour ultra-low temperature version rated to minus 40 degrees Celsius. Smaller formats cover the same ground for handheld equipment, including the BB-2557/U, half-size MBITR packs for the PRC-148 radio and the CSEL survival radio battery. The Conformal Wearable Battery is a flat 148 watt-hour pack designed to sit in body armour rather than in a pouch, which is the direction dismounted soldier power has been heading for a decade.

Charging is treated as its own product line rather than an afterthought. The Advanced Bulk Charger family runs from a two kilowatt unit down to desktop and single-bay chargers, with vehicle-mounted variants that first went into service on Stryker vehicles, plus medium-rate chargers, USB chargers for radio batteries and a long list of adapters, cables and interface plates.

The vehicle line is newer. Bren-Tronics fielded its first lithium-ion 6T battery in 2015, ahead of the US Army performance specification that now governs the format. The current 6T products include an ultra high capacity variant and a version built to the MIL-PRF standard under the Hawker ION-X name, offering cold cranking to 1100 amps at minus 18 degrees Celsius and 400 amps at minus 40 without pre-heat. A single 24V unit replaces two or three of the 12V lead-acid batteries it supersedes, roughly halving weight and volume. The high energy variant reaches 142 amp-hours and 3.75 kilowatt-hours and recharges in under an hour.

At the larger end the Brenergy Series 4850 is a five kilowatt-hour lithium-ion block used for expeditionary and stationary storage, and the company sells complete ruggedised systems such as a six-pack power unit for deployed sites. Pairing 6T batteries with solar panels and a generator to build a tactical microgrid is an application the company actively pushes. Research, testing, certification and manufacturing all sit in house, which is what allows the company to take a pack through MIL-PRF qualification rather than handing that work to a customer.