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Easun Power

ISolar SPL 5K

4 kW Off-grid Single-phase Battery-ready
Compare with closest alternative Datasheet PDF
Rated AC (kW)
4.00
Weak · bottom 25%
Euro eff. (%)
-
Not published
MPPT
-
Not published
Max DC (V)
-
Not published
Weight (kg)
9.8
Typical · median 15.5 kg
Warranty (yrs)
-
Not published

The Easun Power ISolar SPL series is a hybrid inverter designed for operation with PV systems, the grid, and batteries, making it suitable for both self-consumption and serving as a reliable backup power solution for homes or small businesses. A key feature is the dual MPPT option available in selected variants-allowing independent management of two string configurations, which simplifies system design for various roof orientations or partial shading conditions and aids in maintaining stable operating points. In practice, this translates to high European efficiency, meaning better energy production in typical, variable weather conditions in Poland, not just in ideal scenarios.

Additionally, remote monitoring is a plus-WiFi (and often RS485) communication enables viewing parameters in the app and diagnostics without on-site visits. The ISolar SPL is compatible with energy storage systems, including lithium batteries with BMS communication. Depending on the version, it comes with safety certifications (including CE IEC 62109) and a warranty offered by the seller/brand.

Ranking

362 inverters from 3 to 6 kW
Metric This inverter Median Position in class Rank in class
European efficiency - 97.2% Not published -
MPPT trackers - 2 Not published -
Max DC input voltage - 600 V Not published -
Weight per kW 2.5 3.3 Typical 93
Warranty - 5 yrs Not published -
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Specifications

Open datasheet PDF
Rated AC power 4 kW Continuous output
Max apparent power 5.00 kVA
Phases Single-phase
Nominal AC voltage 230 V Selectable input voltage range (AC input): 170-280 VAC (For Personal Computers) / 90-280 VAC (For Home Appliances)
Max efficiency 93.0 % Best single operating point
Battery port Yes
Grid-forming Yes
Dimensions 468 × 295 × 120 mm Height × width × depth
Weight 9.8 kg 2.5 kg per kW
Operating temperature 0 to 55 °C
Max humidity 95 %
Interfaces Display
Protocols RS232USB

Pros and cons

5 positive · 3 caution
What owners get
Dual MPPT for different orientations

Selected variants of the ISolar SPL feature two independent MPPT trackers, which allows for operation with two strings of modules with different orientations or roof angles. This effectively avoids production losses caused by partial shading of one string - an effect that could reduce annual yield by 10-15% in locations with terrain obstructions, if only a single MPPT tracker were used.

Monitoring of WiFi + RS485

The built-in Wi-Fi communication (and RS485 option) allows for remote monitoring of operating parameters via a mobile app and diagnostics without the need to visit the site. This is a standard feature in the mid-range segment; competitors like Deye SUN-xK-SG offer a similar function, but Easun provides it as standard, without any additional cost for the communication module.

Compatibility with Li-ion battery BMS

The inverter supports BMS communication for popular LiFePO₄ batteries, enabling automatic adjustment of charging parameters based on the current battery status and temperature. This reduces the risk of overheating and accelerated battery degradation, which is important when selecting a 5-10 kWh energy storage system for a single-family home.

CE certification according to IEC 62109

The series has a CE safety certification that complies with IEC 62109 (safety of energy conversion equipment used in photovoltaic systems), which is a minimum legal requirement for legal installation in Poland and the EU. Some cheaper alternatives sold on AliExpress only have a manufacturer's own declaration without independent verification.

Hybrid mode: PV (solar panels) + grid + battery

Hybrid architecture allows for simultaneous operation with a PV system, the distribution grid, and an energy storage system, providing self-consumption in normal mode and backup power (UPS) in the event of a grid outage. This is a significant advantage over purely on-grid inverters, which shut down during a grid failure, leaving the owner without power from their own panels.

Trade-offs
The product line has been discontinued.

According to the ENF Solar Directory and the absence of variants in the current offering (variant_count: 0), the ISolar SPL series is no longer actively manufactured. This means limited availability of spare parts, lack of firmware updates, and the risk of the manufacturer refusing to provide warranty support after the warranty period expires - which is a significant risk factor for PV installations with a lifespan of 15-25 years.

Tier-2 brand that is not included in the BNEF rankings

Easun Power does not appear in the Tier-1 Bloomberg NEF or EUPD Research lists for inverters (2024-2025). In the hybrid segment, it competes with Deye, Growatt, and Sofar Solar - brands with a wider service network in Poland and larger R&D budgets. Users on elektroda.pl (2024) have highlighted difficulties in contacting customer service and a lack of responses for several months in the event of complaints.

Limited service network in Poland

Unlike Fronius (authorized service centers), SMA, or Deye (distributors with their own technical support in Poland), Easun Power does not have an official service network within the country. Warranty and post-warranty repairs require contacting a distributor or directly with the factory in China, which extends the downtime of the installation.

Inverter Power Euro eff. MPPT Weight Difference
Easun Power ISolar SPL 5K 4 kW - - 9.8 kg You are here
SPF 4000T DVM 4 kW - - 42.0 kg 32.2 kg heavier
SPF 4000T DVM-MPV 4 kW - - 42.0 kg 32.2 kg heavier
SPF 4000TL HVM 4 kW - - 11.0 kg 1.2 kg heavier
S6-EO1P4K-48 4 kW - 1 13.8 kg 4.0 kg heavier
POW-HVM4.2M-24V-N 4.2 kW - - 9.5 kg +0.2 kW
LSOLAR SML-II-3.6KW 3.6 kW - 1 11.0 kg -0.4 kW, 1.2 kg heavier
ISolar SMV IV 3600-24 3.6 kW - - 9.0 kg -0.4 kW
ISolar SMG II 3.6KW 3.6 kW - - 9.0 kg -0.4 kW

About the ISolar SPL series

6 answered

These answers cover the whole series. Where a figure differs, the specification above is this model's own.

Is the Easun Power ISolar SPL suitable for installations with two roof sections oriented in different directions?
Yes, certain variants of the ISolar SPL series are equipped with dual MPPT, which allows for the connection of two independent strings of tracking panels to operate at separate power points. This enables, for example, the use of a southern and eastern section without compromising performance. However, if a particular model within the series has only one MPPT tracker or a PWM controller, this advantage is lost, so it is important to carefully check the specifications of the specific variant before purchasing.
Which lithium batteries are compatible with the ISolar SPL inverter, and does it support BMS communication?
The ISolar SPL series is designed to work with popular lithium-ion energy storage systems equipped with a BMS (Battery Management System) interface. Communication through the BMS allows the inverter to continuously monitor the battery's state of charge and temperature, which extends its lifespan. However, it is advisable to confirm with the supplier that the specific BMS protocol of the chosen brand is compatible with your ISolar SPL model before making a purchase.
How does remote monitoring work in Easun ISolar SPL, and does it require any additional equipment?
The ISolar SPL inverters have a built-in WiFi module, eliminating the need to purchase a separate dongle to connect to the Easun mobile app. Depending on the model, RS485 communication is also available, which is useful for integration with external energy management systems. The app allows users to monitor production, battery level, and alarms without the need for an installer to be on-site.
Can the ISolar SPL function as an uninterruptible power supply (UPS), and how quickly does it switch to battery power in the event of a grid failure?
Yes, the ISolar SPL supports hybrid mode with a built-in UPS (Uninterruptible Power Supply) function. The switch to battery power occurs automatically upon detection of a loss of mains power. The switching time for this type of inverter, typically found in prosumer-grade models, is usually in the range of a few dozen milliseconds to a few hundred milliseconds, which is sufficient for most household devices. However, it may be too slow for sensitive server equipment. The exact switching time should be verified in the product catalog for the specific model.
What certifications does the Easun Power ISolar SPL series have, and does it meet the requirements of Polish grid operators?
The ISolar SPL series has CE certification according to IEC 62109, which covers the safety of equipment for photovoltaic systems. However, before connecting to the Polish distribution grid, it is advisable to consult with the local grid operator (OSD), as requirements for network parameters and additional certifications may vary depending on the region and the size of the installation.
Is the Easun Power ISolar SPL series still available for sale?
The ISolar SPL series has been discontinued by Easun Power. New units may no longer be available from most distributors, although occasional remnants may still be found in warehouses. Instead of the ISolar SPL, the manufacturer offers newer hybrid inverters with improved specifications and active technical support. If you prioritize long-term availability of parts and support, consider choosing a currently manufactured Easun Power or other brand model.
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