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Drop a substantial amount of dead weight from your electrical tray while unleashing unmatched engine cranking performance. The Antigravity Extreme Power Series ATX20-HD Heavy Duty Lithium Ion Powersports Battery 680CA is an OEM exact-fit replacement starter cell engineered to deliver an exceptional blend of high-density current and heavy-duty reliability [MPN: AG-ATX20-HD]. Pumping out an incredible 680 cranking amps within a standardized housing, this ultra-lightweight LiFePO4 module effortlessly overrides starting resistance caused by large V-twin displacement or cold weather oil drag. By choosing to bypass the internal RE-START reserve circuitry found on alternative models, this specialized performance module maximizes its physical cell volume to allow a deeper level of discharge, providing a higher threshold of usable capacity and continuous electrical throughput for demanding powersports and racing applications.
This high-power motorsports energy core operates within a standardized YTX20 case envelope, featuring an innovative 4-terminal block design that supports both left and right-side negative or positive configuration layouts for effortless cable routing. The advanced internal layout safely absorbs extreme rotational distortion under heavy load and harsh vibration while remaining completely sealed against liquid leakage or corrosive gassing. It can confidently maintain a full shelf charge for up to one entire year, provided the host machine is completely free of active parasitic drains. To preserve long-term cell health and prevent terminal arcing, installers must verify that the vehicle’s alternator or stator charging system is fully operational and regulated below a maximum continuous safety threshold of 14.8V.
This drop-in high-performance configuration matches the standardized dimensions of conventional YTX20, YTX20L, YTX20H, YTX20-BS, YTX20HL-BS, and GYZ20HL lead-acid battery footprint locations. It serves as an ideal replacement for riders seeking maximum usable capacity without an automatic sleep shutdown feature. Its exceptional power-to-weight ratio also makes it heavily utilized as a starting battery in dedicated track day vehicles, sprint cars, and road racing machines with V8 engine architectures where weight reduction is critical. It can be securely mounted in any orientation layout.
CRITICAL INSTALLATION AND SAFETY NOTES: Always disconnect the negative grounding lead first during stock battery removal and connect the negative grounding terminal last during final installation to eliminate the risk of accidental frame shorts. Do not use standard manual or automatic lead-acid battery chargers or tenders that feature an automatic desulfation pulse mode, as this high-voltage process will irreparably damage the internal lithium chemistry and void the manufacturer warranty. Use only a dedicated LiFePO4 lithium smart charger maintaining a regulated voltage profile between 14.4V and 14.6V, and always make sure that all mounting brackets or high-density foam spacers are firmly tightened to prevent physical module shifting.
| Field | Value |
| Brand | Antigravity Batteries |
| Model Series | Extreme Power Heavy Duty Series (HD) / YTX20 Size |
| Part Number | AG-ATX20-HD |
| Case Profile Size | YTX20 Standard Exact-Fit Format |
| Battery Chemistry | Lithium Iron Phosphate (LiFePO4) |
| Cranking Amps Max | 680 CA |
| Capacity Rating (Pb Eq) | 20 Amp Hours |
| Capacity Rating (Actual) | 7.8 Ah (100 Wh) |
| = 12.8V | |
| Maximum Charging Input | 14.8V |
| Terminal Type Design | Versatile 4-Terminal Block Configuration |
| RE-START Technology Included | No (Deep Discharge / Maximum Capacity Optimized configuration) |
| Primary Vehicle Fitment Segment | Cruisers, Heavy Duty V-Twins, Track Race Cars, Full-Size ATVs |
| Product Dimensions | 6.89 x 3.42 x 5.12 inches — 175 x 87 x 130 mm |
| Product Weight | 3.72 lbs — 1.69 kg |
Not every product runs through our fitment finder, and we would rather you confirm exact fitment than rely on a partial filter. Match the specifications against your machine or the part you are replacing, or contact us and we will confirm it for you.
Ask a Parts Specialist →| Brand | Antigravity Batteries |
|---|---|
| SKU: | AG-ATX20-HD |
| MPN | AG-ATX20-HD |
| UPC: | 711811703799 |
| Condition: | New |
| air_freight_prohibited | true |
| not_carb_approved | false |
| ltl_freight_required | false |
| prop_65 | Unknown |
| part_type | powersports |
| epa | N/A |
| carb_acknowledgement_required | false |
| regular_stock | t |
| units_per_sku | 1 |
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