Antigravity Batteries AG-401 Lithium Small Case 12V Powersports Battery — Ultra-Light 15.2 oz, 120 Cranking Amps

The Antigravity AG-401 is an ultra-compact, ultra-lightweight 12V lithium powersports battery built for race and performance applications where every ounce and millimeter matters.

The AG-401 Small Case packs 120 cranking amps into a tiny 4.375 x 1.37 x 3.75 inch footprint and weighs only 15.2 ounces (0.95 lbs). It’s engineered for closed-course racing, small displacement bikes, race conversions and custom builds that require strong starting power without bulk. Because it is a purpose-built race battery, it omits a Battery Management System (BMS) to save weight and maximize output; this requires users to follow lithium-compatible charging and maintenance routines.

How much starting power can this tiny battery deliver?

Despite its small size, the AG-401 supplies 120 cranking amps at 12 volts and a 6Ah lead-acid equivalent rating (2.6Ah actual capacity). That combination delivers reliable starts for small engines and many race setups within its intended limits. It’s optimized for short, high-current draws common in starting systems rather than long-term accessory loads.

• 120 cranking amps for strong engine starts
• 6Ah Pb-eq rating (2.6Ah real) for size-performance balance
• Compact dimensions fit tight battery trays and custom mounts

What charging and maintenance does the AG-401 require?

Because the AG-401 lacks an internal BMS, you must use a charger rated for lithium batteries and follow proper charge profiles. Maintain a regular charging routine after rides and avoid deep discharges or prolonged parasitic drains. For best life and safety, pair the battery with charging systems designed for lithium chemistry and monitor voltage when storing.

• Requires a lithium-compatible charger — do not use standard lead-acid chargers
• Avoid applications with constant parasitic draw or long accessory use
• Store at recommended voltages and recharge after each race session

Will this battery fit my bike and electrical setup?

The AG-401’s small case dimensions make it ideal for race bikes, small-displacement motorcycles, dirt bikes, ATVs and lightweight custom installations. Verify physical dimensions and terminal orientation against your battery tray and starter cable routing. It’s not engineered for passenger cars or vehicles with significant accessory loads.

• Measures 4.375 x 1.37 x 3.75 inches — verify tray clearance
• Compact form factor suits tight or custom battery compartments
• Not recommended for vehicles with parasitic drains or heavy accessories

Is the AG-401 safe for everyday street use?

The AG-401 is primarily a race-focused battery and is labeled for closed-course use; it’s not intended as a drop-in street replacement in most consumer motorcycles. Street applications with continuous electronics or unpredictable charging behavior increase the risk of battery damage. For non-racing daily riders, Antigravity recommends models with integrated management features.

• Intended for race and track use — designed to prioritize weight and power
• Lacks BMS, so not ideal for street bikes with accessory loads
• Choose Antigravity RE-START series for regular street use

Who this battery is for: The AG-401 is aimed at experienced riders, mechanics and race teams who need a featherweight starting source for closed-course competition, small-displacement race bikes, dirt bikes or tight custom builds. If you understand lithium charging requirements, can confirm fitment and intend to avoid systems with steady parasitic drain, this battery offers exceptional weight savings and starting performance. If you want a plug-and-play street replacement or require integrated protection, consider Antigravity’s street-focused models instead.