The Easun Power iSolar SMR II hybrid/off-grid inverter series with grid-connectivity functionality is designed for stable power supply for homes or small businesses using PV, battery, and optionally the grid or generator. The integrated MPPT charge controller simplifies installation configuration, and a 1 MPPT is particularly suitable for simple rooftop systems with one dominant module orientation, where tracking the maximum power point and predictable string performance are essential.
In practice, high European efficiency is also important - this means better performance under typical operating conditions, resulting in significantly more energy available throughout the year, not just under ideal sunlight conditions. The SMR II series supports communication via service interfaces and optional WiFi monitoring, as well as integration with BMS (CAN/RS485), facilitating cooperation with energy storage systems, especially lithium-based ones. Safety is confirmed by compliance with EN/IEC 62109 standards, and the design is oriented towards long-term, maintenance-free operation in domestic and light commercial installations.
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Specifications
Pros and cons
The 60-450 V DC MPPT (Maximum Power Point Tracking) window allows for flexible configuration of the PV string (from 2 to several modules in series) without exceeding the tracking range. An input current of up to 27 A (maximum PV power of 7 kW in the 6 kW variant) provides sufficient capacity for typical residential installations of 4-7 kWp.
The dual-channel CAN and RS485 interface enables automatic parameter exchange with lithium batteries (cut-off voltage, charging current) without manual configuration - a crucial requirement when working with popular BESS (Battery Energy Storage Systems) on the EU market (e.g., Pylontech, DYNESS).
Confirmation of compliance with the European standard for photovoltaic (PV) inverters (Part 1 and 2) - a necessary condition for connecting to the European grid, obtaining funding from national programs (e.g., "My Current"), and obtaining an insurance policy for the installation.
This single device implements network (PZO) operation, off-grid mode, and UPS (switching time under 20 ms according to the product datasheet) functionality, eliminating the need for a separate charging controller and a network inverter in battery-based systems - resulting in lower BOS (Balance of System) costs.
The optional WiFi module, along with RS232 and USB interfaces, allows for parameter monitoring via an application and integration with monitoring software (e.g., Solar Assistant). The built-in communication protocol simplifies setup in residential installations without the need for a dedicated data logger.
The SMR II series is no longer in production (confirmed by ENF Solar and user threads on the DIY Solar Power Forum). The availability of original replacement parts (including MOSFET transistors) and official service support from Easun Power is limited, which significantly increases the risk of long-term operation.
The SMR II hardware software is frozen on an older version and does not accept commands sent via RS232; the Watchpower, Solar Assistant, and ICC-PI programs cannot remotely change the inverter settings. The manufacturer does not provide official update files for this series, which limits operational optimization and integration with newer HEMS systems.
Multiple user reports on the DIY Solar Power Forum (threads from 2022-2024) indicate that MOSFET transistors are failing after several months of intensive use under loads close to their nominal rating. Easun Power has not published MTBF data or an official service bulletin for this series.
Alternatives
About the ISolar SMR II series
These answers cover the whole series. Where a figure differs, the specification above is this model's own.