MidNite Solar MNLR4548RE 4.5kW Pure Sine Inverter with Charger

The MidNite Solar MNLR4548RE is a 4,500W pure sine wave off grid inverter charger built for 48V DC battery systems requiring clean 120VAC output and integrated multi-stage charging in a single compact enclosure. Weighing just 15 lbs. and built in Arlington, WA USA, it delivers the output quality and intelligent control features of a full-sized unit in a form factor suited to space-constrained installations.

Key specifications

• Continuous output power: 4,500W at 77°F (25°C)
• Surge capacity: 6,750W (5-second); 5,625W (5-minute); 4,950W (30-minute)
• Output voltage / accuracy: 120VAC (±2%)
• Input DC voltage range: 40–63VDC (48V nominal)
• Battery charger: 60A maximum; multi-stage charging; optional Battery Temperature Sensor (BTS) for charge temperature compensation
• AC input: 82–140VAC; 48–72Hz; grid and generator support; auto generator start (2-wire generators)
• Dark Start: AC power source can activate the inverter to recharge a fully depleted battery bank; AC pass-through relay remains functional even with a dead battery
• Waveform: True pure sine wave
• Communications: CANbus; multiple auxiliary input/outputs
• Enclosure: Powder-coated aluminum; quiet forced air cooling
• Certifications: UL1741; CSA 22.2 (pending)
• Dimensions: 20.25 L × 9 W × 6 H in.; 15 lbs.
• Warranty: 5 years

Clean power for sensitive loads

Pure sine wave output is required for loads that a modified sine wave inverter cannot drive reliably—variable-speed motors, modern HVAC equipment, medical devices, and most consumer electronics. The MNLR4548RE produces a true sine waveform at 120VAC with ±2% voltage accuracy, keeping sensitive equipment operating within its design tolerances. With 6,750W of 5-second surge capacity, it handles the inrush current of motor-driven loads—refrigerators, pumps, and power tools—without tripping or shutting down.

Dark Start: recovery from full depletion

Most inverter chargers require a minimum battery voltage to power on the charging circuit, leaving a fully depleted battery bank unrecoverable without manual intervention. The MNLR4548RE's Dark Start feature bypasses this limitation: when an AC source (grid or generator) is connected, it activates the inverter directly to begin recharging a dead battery bank. The AC pass-through relay also remains functional whenever AC power is present regardless of battery state, so critical loads stay powered through the recovery process.

Application scenarios

• Off-grid cabin or workshop: Sized for medium loads—lighting, refrigeration, tools, and small HVAC—in a system too small to justify a larger, heavier inverter.
• Backup power for critical systems: Grid-tied installations that need a reliable battery-backed inverter for essential circuits during outages.
• Generator-hybrid systems: Auto generator start support allows the unit to trigger a 2-wire generator automatically on low battery, reducing manual oversight in remote installations.
• Space-constrained installs: At 15 lbs. and 20.25 × 9 × 6 in., the MNLR4548RE fits in enclosures and utility spaces where a standard full-sized inverter would not.

System compatibility

The MNLR4548RE is designed for 48V battery banks across a 40–63VDC operating range. It accepts grid and generator AC input within 82–140VAC and 48–72Hz, making it compatible with most North American utility feeds and common standby generators. CANbus communications allow integration with compatible battery management systems, and multiple auxiliary ports support accessory connections and relay outputs. The optional MidNite Battery Temperature Sensor (BTS) enables charge temperature compensation for extended battery life. Compatible MidNite accessories include the MNGP2 display and associated monitoring hardware.

Why choose the MidNite Solar MNLR4548RE?

The MidNite Solar MNLR4548RE earns its place in the 4.5kW pure sine wave inverter charger category through a combination of features that competing units at this wattage rarely offer together: Dark Start recovery from a fully depleted battery, a 60A multi-stage charger, auto generator start, and a UL1741-listed powder-coated aluminum enclosure—all in a 15 lb. package built in the USA. For installers and system owners who need a dependable, compact off grid inverter charger without sacrificing output quality or recovery capability, the MNLR4548RE is a purpose-built solution backed by MidNite Solar's track record in the North American renewable energy market.