Would you buy or sell a motorcycle without brakes? Then don’t buy a lithium battery without a battery management system (BMS)! EarthX has patent pending technology that makes it the most advanced lithium battery; the highest cranking amp cells; and the only one with a built-in BMS for performance, safety and longevity! This is not an upgrade or optional feature but a REQUIREMENT for a lithium battery to operate correctly. We also have a very unique design with the terminals down the center so if you turn the battery 180 degrees, you will have the positive or negative terminals on the correct side of the battery box. As with all batteries, the positive to positive and negative to negative cable is required. Based on the performance and innovative features on the EarthX brand, we have many OEM manufactures we work with and are providing them to you as a consumer right off the factory line! Including over 11 aircraft companies.