The Black & Decker 5140161-55 Lawn Mower Battery Controller This product is an electronic control module designed to regulate power delivery from the battery to the motor and related systems. It works by monitoring voltage, current, and operating conditions to ensure controlled energy distribution and proper system response during use. The controller helps support smooth startup, cons... https://www.wholetoolbox.com/black-decker-5140161-55-lawn-mower-battery-controller