MidNite Solar Classic 250-SL MPPT Charge Controller, 61A, 12-72V, 250VDC

The MidNite Solar Classic 250-SL MPPT Charge Controller is a streamlined MPPT solar charge controller rated for 250VDC PV input and up to 61A output, built for solar-only charging across 12–72V battery banks. Designed and assembled in the USA, it delivers the same core power and HyperVOC technology as the standard Classic line in a simplified, solar-focused package — with a straightforward menu structure that makes setup faster and ETL listing for both the US and Canada.

Key specifications

• Max PV input voltage — 250VDC; HyperVOC extends effective VOC to 298VDC at a 48V battery
• Max output current — 61A at 12V; 62A at 24V; 55A at 48V; 43A at 72V battery
• Battery voltage — 12–72V nominal; regulation set points 10–100VDC
• Built-in protection — DC Ground Fault Protection (resettable, no fuse to blow); fully protected against PV and battery reverse polarity, over-voltage, and short circuit
• Certifications & warranty — ETL listed to UL1741 & CSA (US & Canada), CE Certified, FCC Class B; 5-year warranty

High efficiency across wide battery voltages

Most MPPT controllers compromise between PV string size and battery bank voltage. The Classic 250-SL achieves 98% power conversion efficiency across its full 12–72V battery range, keeping harvest losses minimal whether the system runs at 24V or 48V. Its built-in DC Ground Fault Protection is resettable and requires no fuse replacement — a practical advantage on installations where access for maintenance is limited.

Key Applications

• Off-grid residential solar — charges 24V, 48V, and 72V battery banks at up to 62A, 55A, and 43A respectively, accommodating high-voltage string configurations that would exceed the input ceiling of 150V or 200V controllers.
• Remote cabins and rural properties — the simplified menu and solar-focused feature set make it well suited to standalone PV systems where setup simplicity and long-term reliability matter most.
• Cold-climate installations — HyperVOC safely accommodates the elevated open-circuit voltages that occur on cold mornings without tripping or requiring a derated array.
• Positive-ground systems — fully supported with two-pole input and output breakers for RV, marine, and specialty wiring configurations.

HyperVOC, solar MPPT, and data logging

• HyperVOC — MidNite Solar's proprietary input extension adds the battery voltage to the 250VDC ceiling, allowing effective PV open-circuit voltages up to 298VDC at a 48V battery — a real-world safety buffer for cold-morning voltage spikes on longer, higher-voltage strings.
• Solar MPPT mode — the tracking algorithm is optimized for PV arrays, extracting maximum power across varying irradiance and temperature conditions throughout the day.
• 380-day data logging — 380 days of daily history plus 24 hours of 5-minute interval data stored on-board, accessible via the built-in graphical display or through the included MNGP remote display.
• Battery temperature compensation — automatic when a MidNite Battery Temperature Sensor (MNBTS) is connected, with adjustable mV per degree C per 2V cell for accurate charge profiling across seasons.

Wiring, communications, and system integration

The Classic 250-SL communicates via Modbus over RS232. The MNGP graphical display is included standard with a 3-foot networking cable and can be relocated using a standard 4-conductor phone cable — no hub required, and a second display can be added. Terminals accept 75°C (167°F)-rated conductors. Conduit entries include single 1-inch (25.4mm) knockouts on both sides and two ¾-inch (19.05mm) knockouts on the back. The environmental rating is indoor Type 1 (IP30); adding the Classic Drip Shield upgrades protection to IP22 for damp locations. Two programmable auxiliary outputs handle external load disconnect and reconnect. The Classic 250-SL runs in parallel with other Classic SL, Standard Classic, and Classic Lite units via the Stacking/Follow-Me feature using standard phone cable.

Why choose the MidNite Solar Classic 250-SL?

The MidNite Solar Classic 250-SL MPPT Charge Controller offers the full output power and HyperVOC capability of the standard Classic 250 in a solar-focused design that trades the arc fault detector and Ethernet port for a lower price point and a simpler menu that reduces commissioning time on straightforward PV installations. The 250VDC input rating is the highest in the Classic SL line, making it the right choice for installations with long string runs, high-efficiency modules with elevated VOC ratings, or system designs that push against the input limits of lower-rated controllers. The MNGP graphical display ships standard — not as an add-on — and the 5-year warranty, ETL listing for the US and Canada, and domestic design and assembly remain unchanged.