Deye (Ningbo Deye Inverter Technology Co.) has become known in the field of solar energy storage in recent years with its wide range of hybrid inverters. Hybrid inverters can simultaneously feed solar energy into the grid and charge and discharge batteries, providing flexible energy management. Deye’s product range includes single-phase and three-phase models, from small-scale (3-10 kW) residential systems to high-power (50-80 kW) industrial solutions. In addition, Deye inverters are compatible with both 48 V (low voltage) and high voltage batteries, depending on the type. Below, we will review the main features and differences between single-phase vs. three-phase and low voltage vs. high voltage battery-powered Deye hybrid inverters.
Single-phase vs. three-phase hybrid inverters
Single-phase hybrid inverters:
Single-phase Deye inverters connect to a single phase (230 V), typically for residential use or locations where the grid connection is single-phase. These models are available in capacities from 3.6 kW to 10 kW, making them suitable for the entire solar needs of an average household. They support low-voltage (48 V) batteries, which is standard for residential storage.
Main features of single-phase Deye hybrid inverters:
- High charging current: up to 190 A maximum charging and discharging battery current to the 48 V battery. This allows for high power output and fast battery charging.
- Significant PV capacity: for example, up to 15-16 kW of solar panels can be connected to models around 8 kW, with a wide MPPT voltage range (150-425 V) for high solar energy utilization.
- Flexibility and expandability: up to 16 inverters can be connected in parallel, working together in grid-connected or stand-alone operation. The system also supports the parallel connection of multiple batteries, so storage capacity can be expanded.
- AC-coupling and backup capability: the inverter can be retrofitted to an existing solar system via AC-coupling and also supports charging from a diesel generator as an emergency power source. In island operation, it can handle short-term (10 sec) peaks with a 2x overload reserve.
- Manageability: It has a built-in color touchscreen and several communication options (RS485, CAN, WiFi/GPRS module) for monitoring. It is housed in a durable, IP65-protected housing and operates reliably even in extreme temperatures (-40°C–+60°C range).
Three-phase hybrid inverters
The three-phase Deye models are connected to three phases (3×400 V + N), thus providing a balanced supply to the grid on all three phases. These are typically chosen if the building has a 3-phase connection – especially for medium and large systems, or if grid regulations require this for higher inverter powers. Deye three-phase hybrid inverters are available in different series with powers ranging from 5 kW to 80 kW.
Their main characteristics:
- Wide range of power and MPPT options: There are smaller models with 5-20 kW with 2 MPPTs, as well as larger industrial versions with 30-50 kW (3-4 MPPTs) and even 60-80 kW (6 MPPTs). This means that the Deye three-phase hybrid inverter can be scaled from a family home to an industrial hall.
- High-voltage battery support: Most three-phase models use high-voltage batteries to increase efficiency (more on this in the next section). However, some series are also available with 48V batteries – for example, the SUN-14–20K-SG05LP3-EU models are specifically designed to operate with a 48V (low-voltage) battery, with an internal transformer design to provide the correct output voltage.
- High output flexibility: Deye's three-phase inverters support 100% phase imbalance, meaning they can deliver up to half of the rated power on a single phase without loading the other two phases. This is important in locations where loads are not evenly distributed across the phases.
- Parallelization and islanding: As with single-phase inverters, up to 10 three-phase inverters can be operated in parallel, operating as a common system (on-grid or off-grid). This allows for the construction of huge systems with capacities of up to several hundred kW. They can also cooperate in islanding, for example by sharing the load and reserve capacity with microprocessor control.
- Other features: Similar to single-phase, there is 6-time band charge/discharge control (e.g. peak-time optimization for power suppliers), the possibility of diesel generator integration as a backup generator, and full network protection (island shutdown, overvoltage, short circuit protection, etc.). Their efficiency is outstanding, typically around 97–98%, which minimizes energy loss.
Low voltage vs. high voltage battery systems
One of the key technical parameters of energy storage systems is the battery voltage level, which determines the amount of current transferred, the efficiency of the system, the cabling and protection requirements, and the cost structure of the entire investment. Deye's system offering can be divided into two main categories:
- Low voltage (LV) batteries – typically with a nominal voltage of 48 V,
- High voltage (HV) batteries – where the system voltage is above 200 V, up to 800–900 V.
Low voltage systems
Low-voltage 48V batteries are primarily used in residential systems, but Deye also offers three-phase inverters that are specifically optimized for this battery voltage (e.g. SUN-14–20K-SG05LP3-EU). The Deye SE-G5.1 Pro-B model is a 5.12 kWh, 51.2V LiFePO₄ battery, of which a single battery can be enough to build a basic system. This is especially useful for those who want to gradually expand their energy storage capacity.
Advantages:
- Low entry threshold: the system works with just one battery, no expensive controller or minimum battery pack required.
- Modularly expandable: up to 64 SE-G5.1 Pro-B batteries can be connected in parallel, allowing the system to be expanded up to 327 kWh capacity.
- Easier installation and cheaper cabling: because the voltage is lower, safety distances and protection requirements are smaller.
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Affordable price: LV batteries – including the SE-G5.1 Pro-B type – are significantly cheaper than high-voltage batteries, so the overall system price can be lower.
Disadvantage:
- At higher power, the required current is significant: for example, in the case of a 10 kW system, ~200 A flows, which the inverter and the wires must withstand. For this reason, LV inverters operate with more complex cooling, an internal transformer, and larger cross-section cabling – this can be burdensome from both a technological and cost perspective for large systems.
High voltage systems
High voltage systems are based on connecting multiple battery modules in series to create a higher system voltage (e.g. 256–819 V). The Deye BOS-G Pro series modules are also 5.12 kWh (51.2 Vdc), but they only work in series – for example, the BOS-G25 Pro version requires at least 5 modules and a BOS-G-PDU control box is also part of the system. This means that the minimum starting capacity is 25.6 kWh, and the initial cost is also higher.
Advantages:
- High efficiency: the same power can be transmitted with much less current, resulting in lower heat losses.
- Smaller cross-section cables: less loaded switchgear.
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Ideal for large systems: BOS-G batteries and matching inverters (e.g. SUN-25K–80K) are perfectly scalable for industrial-level systems.
Unified rack design: professional appearance, tidy installation, easy maintenance.
Disadvantages:
- Higher entry cost: the system can only be started with several modules (min. 5), plus the price of the control unit is added.
- More complex installation: often only a professional can do it due to the voltage level.
- Later expansion: attention must be paid to module identity, because serialization imposes stricter requirements than parallelization.
Summary and recommendation
Deye hybrid inverters stand out on the market with their technological flexibility and extremely wide product range. Whether single-phase or three-phase systems, low or high voltage batteries, Deye offers an optimized solution for every need.
Phase design: for smaller family homes with single-phase grid connection, a 5–10 kW single-phase inverter with a 48 V battery may be an ideal choice. For larger buildings, apartment buildings or three-phase connections, it is worth choosing a three-phase inverter, which offers better phase balancing, higher performance and scalability.
Battery voltage: if you already have a 48V battery or want to gradually build out your system, Deye LV inverters (e.g. SUN-8K-SG05LP1-EU) are a compatible and cost-effective solution. Conversely, for newly built, larger capacity systems, it may be advisable to use a three-phase inverter combined with a high voltage (HV) battery, which allows for more efficient energy conversion and greater power management in the long term.
Island operation and safety: all Deye hybrid inverters support grid feed-in, but can also operate in full island operation if required, thus providing reliable backup energy even in the event of a power outage.
