SMA Sunny Island 4.4M (SI4.4M-13)3.3kW 48V single-phase battery inverter-charger

Overview

The SI4.4M-13 is the compact Sunny Island, rated 3300W continuous at 230V with 4400W for 30 minutes and 5500W for 3 seconds from a 48V battery. It charges at up to 75A and accepts up to 50A from a generator or the grid. One unit supplies a single-phase system and three units can form a three-phase system; parallel single-phase clusters and multicluster are not possible with this model. It weighs 44kg.

• 3.3, 4.6 and 6kW rated, up to 11kW for 3s
• 48V battery input, 41–63V, lead-acid or lithium-ion
• 50A AC input for grid or generator
• Three units form a three-phase system
• Parallel and multicluster operation (6.0H, 8.0H)
• Integrated generator management, IP54

How it works

Sunny Island is a bidirectional battery inverter that controls the energy balance of an off-grid system, a battery-backup system or a system for increased self-consumption. Its AC-1 port supplies the loads with a 230V, 50Hz grid formed from a 48V battery; the AC-2 port connects a utility grid or generator at up to 50A and 11.5kW. PV inverters are coupled on the AC side, so existing grid-tied PV inverters can be integrated. Three Sunny Island units together build a three-phase system with rotating field.

Key features

Overload reserves are generous: the 6.0H supplies 6kW for 30 minutes and the 8.0H 8kW, with 11kW for 3 seconds on both. Charge current reaches 75, 110 or 140A, using an IUoU procedure with automatic full and equalisation charging for flooded and VRLA lead-acid batteries, while lithium-ion batteries use their own management system. Battery capacity can range from 100 to 10000Ah for lead-acid and 50 to 10000Ah for lithium-ion. Generator management covers autostart, warm-up, run times and state-of-charge-based requests.

Installation and compatibility

The 467×612×242mm enclosure is IP54 and suited to indoor or weather-protected outdoor installation from -25 to +60°C. The 6.0H and 8.0H can be connected in parallel and in multicluster systems via SI-SYSCAN with SMA Multicluster boxes; the 4.4M must not be used for single-phase single-cluster or three-phase multicluster systems. There is no internal DC fuse, so an external battery fuse is required. SMA's approved list covers lithium batteries from BYD, Pylontech, LG Energy Solution, BMZ, Axitec, Tesvolt, Dyness and others.

Monitoring and settings

Configuration runs through the web interface via Speedwire, with direct Sunny Portal access over Webconnect or Sunny Portal powered by ennexOS through an SMA Data Manager M or L. A micro SD card can store extended logs, and two multifunction relays can control generators or loads. For on-grid use, a Sunny Home Manager or SMA Energy Meter and, for backup, an automatic transfer switch are added. Without a switch box, backup switching takes 0ms with high-impedance and 20ms with low-impedance grid failure on the H models.

Questions and answers