Antigravity Batteries® ATX20-HD Heavy Duty Lithium Ion Battery with Dual Polarity and Battery Management System (BMS) - 900 CCA 5.18 Pounds 30Ah - Replaces YTX15, YTX15L, YTX20, YTX20L, YTX20H, YTX20HL, YTX20-BS, GYZ20H, GYZ20L, GYZ20HL

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Antigravity Batteries® ATX20-HD Heavy Duty Lithium Ion Battery with Dual Polarity and BMS

Replaces YTX15, YTX15L, YTX20, YTX20L, YTX20H, YTX20HL, YTX20-BS, GYZ20H, GYZ20L, GYZ20HL

This is the NEW Heavy Duty version of the ATX20 designed with a significant jump in Power and Capacity for accessorized Touring bikes and larger displacement motors.

  • YTX20 Standardized Case Size
  • Cranking Amps: 900
  • Amp Hours: 30Ah (PbEq), 15Ah (1C Rate)
  • Weight: 5.18 Pounds
  • Width: 3-1/2"            
  • Length: 6-15/16"            
  • Height: 5-1/8"
  • Lighted Voltage Indicator to see state of charge (Does NOT have RE-START)


Antigravity Batteries is proud to introduce the NEW ATX20-HD and ATX30-HD. The NEW Heavy Duty Series was specifically designed to offer SIGNIFICANTLY more Amp Hours and Power than the original versions of the ATX20/30 to meet the special needs of those looking for the most compact yet powerful battery. These Batteries are intended for those special applications like heavily accessorized Touring Motorcycles, Racing and Street Performance Vehicles, Experimental Aircraft and more. HD models offer over TWICE the capacity of competitors Lithium Batteries of the same size! They also come with a Voltage Indicator test button on the battery so you can easily check its charge level. Simply put, these are the most powerful and compact Batteries available from any manufacturer.

The NEW Heavy Duty ATX20 and ATX30 do not have a RE-START built-in jump-starting feature but offers a deeper level of discharge for more usable capacity and more power for cranking. They also offer a FULL Battery Management System (BMS) to protect the battery from over-discharge and over-charge as well as having Thermal Protections. This makes for the safest and longest life-cycle possible.


  • Most Advanced Lithium Battery on the market.
  • FULL Battery Management System (BMS) including Over-Discharge, Over-Charge*, Thermal Protections and Cell Balancing.
  • LONGER LIFE: Up to twice the lifecycle of lead/acid, and other Lithium batteries due to full Battery Management system.
  • HI POWER: Up to 2 Times the Cranking Amps of similar sized lead/acid batteries. Better Starting and higher voltage at start-up.
  • ULTRA LIGHTWEIGHT: Up to 70% lighter than equivalent lead/acid battery. Up to 15 lbs in bikes or 45 pounds in Race Cars.
  • 4 Terminal DUAL POLARITY Design allows easy installation in any vehicle. Fits right or left hand Negative or Positive connections. No more looking for the correct Terminal locations in certain bikes or cars.
  • LOW SELF-DISCHARGE: Antigravity Batteries do not self-discharge like Lead/Acid Batteries. They can hold a charge up to a year provided there are no “Parasitic Drains” (accessories that draw power when bike is off, i.e. alarms, ECUs, GPS, heated grips, and other accessories the vehicle might have).
  • DURABILITY: Our lithium batteries are shock and vibration resistant making them perfect for Racing, and other applications requiring a durable battery.
  • MOUNTING: You can mount our battery in any orientation, there are no liquids to spill or drain out.
  • ENVIRONMENTALLY SAFER BATTERY: No Acid or Heavy Metals such as Lead, Cadmium, or Mercury.

*Over-Charge protection will not protect from a faulty/old Voltage Regulator spiking Hi-Voltages to Battery. If you have a Pre-1990s Motorcycle; it is over 25 year old and most likely not set-up for a lithium battery even if it has a brand-new factory reg/rec.

***Use a lithium charger as well as a lithium reg/rec to avoid damaging the battery***


  • Width = 3-1/2"            
  • Length = 6-15/16"            
  • Height = 5-1/8"
  • Weight = 5.18 Pounds


  • Length = 175mm          
  • Width = 89mm            
  • Height = 130mm
  • Weight = 2.35 KG


  • Battery (Charged)
  • (2) Terminal Bolts
  • 3 Year Warranty (See manufacturers website for details)


  • Direct replacement for these OEM battery sizes:
  • YTX15
  • YTX15L
  • YTX20
  • YTX20L
  • YTX20H
  • YTX20HL
  • YTX20-BS
  • GYZ20H
  • GYZ20L
  • GYZ20HL
  • Intended for those special applications like heavily accessorized Touring Motorcycles.
  • Racing and Street performance vehicles.
  • Experimental Aircraft and more.
  • Great for extra large, high-performance V-Twin motors.
  • Not for use with PWC (Personal Water Craft.)

1 Review Hide Reviews Show Reviews

  • 5
    Antigravity Battery

    Posted by Allen on 3rd Nov 2020

    Installed this on a 2017 Ultra Limited Harley Davidson. It was a little bit wider than the box, made slight modification to battery box, fit great.
    Works well cranks faster than the original battery.