Yamaha YFM400FB Big Bear The YTX20L-BS battery is compatible with the Yamaha YFM400FB Big Bear ATV. These compatible alternatives to the Motocross products are manufactured 100% brand new by a manufacturer that is not endorsed or associated with Yuasa and are guaranteed by Apex Battery to work with your electronics. The state-of-the-art lead-acid battery is the valve-regulated type (sometimes called sealed or maintenance-free) which fixes the acid electrolyte in a gel or in an absorptive fiberglass mat. The advantage of this design is that the battery needs no water additions can be operated in any position and can be used in close proximity to people and sensitive equipment. 11.2 12 18 250 6.88 3.44 6.13 1 Year Dry Charge AGM PowerMax