Mighty Max Battery YTX20L-BS 12V 18Ah Motorcycle Battery — 270 CCA, AGM Sealed, Maintenance-Free

The Mighty Max Battery YTX20L-BS is a sealed 12V 18Ah AGM motorcycle battery delivering 270 CCA in a maintenance-free, rechargeable package ready to install.

This compact absorbed glass mat (AGM) sealed lead-acid (SLA) battery is designed for powersports applications that demand consistent starting power and reliable electrical performance. Pre-charged and sealed at the factory, the YTX20L-BS arrives ready to fit into ATVs, motorcycles, personal watercraft, jet skis, and snowmobiles. Its spill-proof design and vibration resistance make it suitable for vehicles that see rough terrain and wet conditions.

How much starting power and runtime does this battery provide?

The YTX20L-BS supplies 270 cold cranking amps (CCA) for strong starts in cool conditions and an 18 amp-hour capacity for accessory and ignition loads. It’s built to maintain steady voltage under load so lights, pumps, and electronics stay powered between starts.

• 270 CCA for reliable engine starts.
• 18 Ah capacity for sustained accessory use.
• AGM construction supports consistent voltage output.

Is the battery durable enough for off-road and marine use?

Yes — the sealed AGM design tolerates shocks, vibration, and varied mounting positions, so it holds up on rough trails and in marine environments. The weatherproof casing and maintenance-free construction reduce corrosion risk and eliminate the need for periodic electrolyte checks.

• Sealed, spill-proof housing for wet environments.
• Resistance to vibration for rugged terrain use.
• Can be mounted in multiple orientations for flexible installation.

What are the physical dimensions and polarity details I need to know?

The battery measures 6.88 inches long, 3.50 inches wide, and 6.13 inches tall, making it compatible with many standard YTX20L-BS trays and boxes. Polarity is negative on the left and positive on the right when viewed from the terminal side, and the listing includes the battery plus terminal screws only.

• Dimensions: 6.88" L x 3.50" W x 6.13" H.
• Terminal layout: negative left, positive right.
• Includes battery and screws; no harness or mounting accessories.

How do I charge and maintain this battery for best life?

The YTX20L-BS ships pre-charged and sealed; for long-term storage or after deep discharge, use a charger compatible with AGM/SLA chemistry and follow manufacturer charging profiles. Because it’s maintenance-free, there’s no need to add water—just keep terminals clean and securely mounted.

• Use an AGM-compatible charger for optimal recharge cycles.
• No watering or electrolyte maintenance required.
• Store charged and in a cool, dry place for longer shelf life.

Who is this for: The Mighty Max Battery YTX20L-BS is aimed at riders and powersports owners who need a dependable, maintenance-free battery that tolerates vibration and wet conditions. It fits a wide range of motorcycles, ATVs, jet skis, and snowmobiles where compact size, dependable cold starting, and a sealed design are priorities. Backed by a one-year limited warranty, it’s a practical replacement or upgrade for enthusiasts and fleet operators looking for consistent performance without routine maintenance.