Limitless Lithium Retro Pro 56

Serious Lithium Power for Serious Car Audio Systems

The Limitless Lithium Retro Pro 56 is a high-performance 12V LiFePO4 lithium battery engineered for demanding high-output electrical and car audio systems.

With 56Ah of actual capacity, up to 750 amps of continuous discharge, and 1,200–1,300 amps of burst discharge capability, the Retro Pro 56 is built to supply the current serious amplifiers demand.

Depending on alternator output and the overall electrical system, the Retro Pro 56 can support approximately 9,000–13,000 watts continuously and up to 16,000 watts of burst power.

POWER CAPABILITY

Continuous Power Support: 9,000–13,000 Watts
Burst Power Support: Up to 16,000 Watts

Continuous power capability is dependent on alternator output:

100A–400A Alternator Range

For maximum performance, your charging system, wiring, grounds, alternator capacity, and overall electrical system should be properly matched to your amplifier system.

56AH OF ACTUAL CAPACITY

The Retro Pro 56 provides 56Ah of actual lithium capacity — not a lead-acid equivalent rating.

Its estimated lead-acid equivalent capacity is approximately 200–240Ah, delivering substantial reserve capacity without the size and weight associated with a comparable traditional battery bank.

HIGH-CURRENT PERFORMANCE

Built for demanding electrical systems, the Retro Pro 56 delivers:

• 750A Continuous Discharge

• 1,200–1,300A Burst Discharge

• Up to 400A Maximum Charge Current

• 9,000–13,000W Continuous Power Support

• Up to 16,000W Burst Power Support

NOTE: Burst amperage is temperature dependent. Charging above 400 amps may reduce battery cycle life.

LIFEPO4 CHEMISTRY

The Retro Pro 56 utilizes LiFePO4 (Lithium Iron Phosphate) chemistry and features an internal balance board to help maintain proper cell balance.

IMPORTANT: The Retro Pro 56 does not have an integrated Battery Management System (BMS). Proper charging voltage, installation, system monitoring, and battery maintenance are essential.

SPECIFICATIONS

• Model: Retro Pro 56

• Nominal Voltage: 12V

• Resting Voltage: 13.1V–13.4V

• Capacity: 56Ah Actual

• Lead-Acid Equivalent: Approximately 200–240Ah

• Chemistry: LiFePO4

• BCI Case Size: Group 24

• Weight: 21 lbs

• Height: 8.75"

• Depth: 6.5"

• Width: 10.125"

• Terminal Size: M8 × 1.25

• Terminal Orientation: Positive Left

• Operating Temperature: -22°F to 140°F (-30°C to 60°C)

• Maximum Charge Voltage: 14.8V

• Maximum Charge Current: 400A

• Continuous Discharge: 750A

• Burst Discharge: 1,200–1,300A*

• Continuous Wattage Support: 9,000–13,000W*

• Burst Wattage Support: Up to 16,000W*

• Life Cycles: Approximately 2,000 cycles @ 80% DOD

• Internal Balance Board: Yes

• BMS: No

Performance is dependent on temperature, alternator output, charging system, wiring, and overall electrical-system configuration.

BUILT FOR HIGH-OUTPUT CAR AUDIO

When you're running multiple high-power amplifiers, large subwoofer systems, or competition-level electrical demands, your battery bank needs to be capable of supplying massive amounts of current quickly.

The Retro Pro 56 combines high continuous discharge capability, substantial reserve capacity, and compact LiFePO4 technology to create an electrical foundation capable of supporting serious car audio power.

WARRANTY

Every Limitless Lithium Retro Pro 56 includes a 1-year warranty from the date of purchase.

Register your battery within 30 days of purchase to receive an additional 2-year warranty extension, providing a total of 3 years of coverage against manufacturing defects.

HIGH POWER. HIGH CAPACITY. BUILT TO PERFORM.

For systems demanding 10,000 watts and beyond, the Limitless Lithium Retro Pro 56 provides the current capability and reserve capacity needed to keep high-output amplifiers supplied with serious power.