The Antigravity AG-401 is the smallest battery in the Antigravity line and among the most compact lightweight lithium motorsport batteries available. It exists for builds where the battery needs to disappear: kickstart-only Harley choppers and bobbers running lights and ignition, race bikes chasing every ounce, and total-loss setups.

It hides inside a small battery box or frame tube and mounts in any orientation.

Features

• Smallest, lightest battery in the Antigravity line
• Built for kickstart-only V-twins, race, and total-loss applications
• Mounts in any orientation; vibration resistant
• Large all-brass terminal design
• LiFePO4 chemistry; holds a charge up to a year without parasitic drains

What's Included

• AG-401 lithium battery
• Adhesive-backed installation foam

Installation Notes

• Small Case batteries use balance charging without an onboard BMS; Antigravity positions them for race, off-road, and custom applications.
• On classic bikes from the mid-1980s and earlier, update the charging system to a modern voltage regulator before running a lithium battery; a failing regulator can overcharge and damage it.
• Not intended for electric-start V-twins; step up through the 8, 12, and 16-cell Small Case sizes as cranking demand grows.
• Charge only with a lithium-compatible (LiFePO4) charger such as the Antigravity SC-2 or SC-4 Super-Charger. Lead/acid chargers, especially those with desulfation or recondition modes, can damage lithium batteries.

Specifications

• Voltage: 12V
• Format: 4-cell Small Case
• Chemistry: LiFePO4 (balance charging, no onboard BMS)

Fitment

Sold as a compact power cell for custom and race builds rather than against a factory fitment chart. Mount in any orientation with the included adhesive foam, in a battery box, or tucked into the frame; confirm dimensions and cranking requirements against your build.