Antigravity Q85/Group 35 Lithium Car Battery w/Re-Start - AG-35-40-RS

The Antigravity AG-35-40-RS Group 35/Q85 Lithium Car Battery with RE-START Technology is a direct-fit, drop-in replacement for standard BCI Group 35/Q85 lead-acid batteries in performance cars, passenger vehicles, and trucks. Engineered by Antigravity Batteries around a LiFePO4 (lithium iron phosphate) chemistry and a sophisticated on-board Battery Management System, this is the first intelligent lithium automotive battery to offer wireless, remote-activated built-in jump starting — so a dead battery never has to leave you stranded at the side of the road again.

Key Features & Benefits

• Wireless RE-START Technology: If the battery's BMS puts itself to sleep to prevent a full discharge (say, after leaving your lights on), simply press the included Keyfob remote from inside the car — no hood access needed — to reactivate reserved power and start your vehicle. You can also trigger RE-START manually via the button on top of the battery.
• 1,500 Cranking Amps: With 1,500 CA on tap, this lithium battery delivers confident, reliable cold-cranking performance well-suited for high-performance engines and demanding start cycles.
• Ultra-Lightweight Design: Antigravity states this battery is approximately 70% lighter than a comparable lead-acid unit — a potential weight reduction of up to 40 lbs — a significant benefit for performance builds, track cars, and anyone chasing improved handling balance.
• Full Battery Management System (BMS) Built-In: The on-board BMS actively manages over-discharge protection, over-charge protection, short-circuit protection, cell balancing, and thermal protection. This keeps the battery operating in its optimal range, maximizes safety, and extends service life.
• LiFePO4 Chemistry for Long Service Life: Antigravity cites an expected service life of 7–9 years (depending on use and climate) and notes the RE-START line offers 2x to 3x the lifecycle of a conventional lead-acid battery — meaning fewer replacement cycles and lower long-term cost of ownership.
• Exact OEM Drop-In Case Size: Built to BCI Group 35/Q85 dimensions (9 x 6.85 x 8.6 inches, L×W×H), so it installs into the factory battery tray without modification on compatible vehicles.
• Threaded M8×1.25 Terminals: Properly threaded terminals provide a secure, vibration-resistant connection — important on performance and track vehicles.
• 40 Ah Actual Capacity: A genuine 40 amp-hour rating ensures adequate reserve capacity for modern vehicles with high electrical loads, audio systems, or extended accessory use.
• Safest Lithium Chemistry: LiFePO4 is widely regarded as the most thermally stable lithium chemistry available, and Antigravity's full BMS adds additional safeguards on top of that inherent chemistry stability.

Specifications

• Part Number: AG-35-40-RS
• UPC: 711811703928
• BCI Group: Group 35 / Q85
• Voltage: 12V
• Capacity: 40 Ah (Actual)
• Cranking Amps: 1,500 CA
• Dimensions (L×W×H): 9 × 6.85 × 8.6 inches
• Chemistry: LiFePO4 (Lithium Iron Phosphate)
• Terminal Type: Threaded M8×1.25
• Expected Service Life: 7–9 years (use and climate dependent)
• RE-START Activation: Wireless Keyfob remote (included) or manual button on battery top
• Weight Savings: Up to ~40 lbs vs. comparable lead-acid (approximately 70% lighter)

Fitment

The AG-35-40-RS is built to BCI Group 35 / Q85 OEM case dimensions, making it a direct drop-in replacement for any vehicle that originally uses a Group 35 or Q85 lead-acid battery. This size is common across a wide range of performance cars, daily drivers, and light trucks — including many Honda, Subaru, Nissan, Toyota, Mitsubishi, and domestic performance vehicles that specify a Group 35 battery from the factory.

Because fitment depends on your specific vehicle's battery tray, terminal orientation, and hold-down configuration, we strongly recommend verifying your current battery's BCI group number before ordering. Use the Antigravity Battery Finder tool or contact ThreePiece.us directly if you are unsure whether your vehicle accepts a Group 35/Q85 size. Note: adult signature is required upon delivery per Antigravity's shipping policy.

What's in the Box

• Antigravity AG-35-40-RS Group 35/Q85 Lithium Car Battery
• Wireless Keyfob Remote (for RE-START activation)

Why Buy from ThreePiece.us

ThreePiece.us has been serving performance enthusiasts since 2014, with over 10,000 customers and a team of specialists ready to help you verify fitment before you buy. Have questions about whether the AG-35-40-RS fits your specific vehicle? Call us at 813-535-5801 or use our fitment contact form — we'll confirm compatibility so you order with confidence.

• Free Shipping on every order within the continental US — no minimum required.
• Affirm Financing available at checkout, so you can spread the cost of a premium lithium battery upgrade over time.
• Expert Fitment Support from a team that knows performance vehicles inside and out.
• 100% Genuine Products — we never sell replicas or grey-market goods.

Frequently Asked Questions

Q: How does the RE-START wireless jump-starting actually work?
A: The Antigravity BMS monitors the battery's state of charge continuously. If the battery is being drained toward a damaging discharge level (for example, from a light left on), it will put itself into a sleep/protection state — but crucially, it reserves just enough energy to restart the vehicle. When you're ready to start the car, press the button on the included Keyfob remote. This wirelessly wakes the battery and releases the reserved energy so you can crank the engine and drive away. You never have to open the hood or connect jumper cables. You can also press the physical RE-START button on top of the battery itself if you prefer.

Q: Will this battery fit my vehicle without any modifications?
A: The AG-35-40-RS is built to exact BCI Group 35/Q85 OEM case dimensions (9 × 6.85 × 8.6 inches), so it is designed to drop directly into factory battery trays that accept a Group 35 or Q85 battery. Terminal type and orientation, hold-down bracket style, and cable length may vary by vehicle — check your owner's manual or current battery label for your BCI group number. If you're unsure, contact ThreePiece.us before ordering and we'll help confirm fitment.

Q: Does a lithium battery require a special charger?
A: Antigravity recommends using a charger designed for lithium (LiFePO4) batteries for best results and longevity. The manufacturer offers their own SUPER-CHARGER line for this purpose. Many modern smart chargers with a lithium or LiFePO4 mode are compatible — check your charger's specifications. Using an incompatible charger could affect battery life or trigger the BMS protection circuits.

Q: How long will this battery last compared to a stock lead-acid battery?
A: Antigravity states the AG-35-40-RS RE-START line is expected to deliver 7–9 years of service life depending on usage and climate, and cites a lifecycle 2x to 3x longer than a conventional lead-acid battery. The built-in BMS — with over-discharge, over-charge, short-circuit, thermal, and cell-balancing protections — actively works to preserve the battery's health throughout its service life.