Deye BOS-G40 Pro

36.86 kWh usable LFP High voltage

Compare with closest alternative Datasheet PDF

Usable (kWh)

36.86

Typical for its class

Round-trip (%)

Not published

Power (kW)

41.0

Strong · top 13%

Cycles

6000

Typical · median 6000

Weight (kg)

428.0

Typical · median 310.0 kg

Warranty (yrs)

Typical · median 10 yrs

High-voltage energy storage solutions in the 19-inch rack standard, designed for quick and predictable installation and service. The key advantage lies in the LiFePO4 (LFP) chemistry - compared to NMC, it offers higher thermal stability, greater operational safety, and excellent durability in daily charging and discharging cycles. Parameter control is managed by an intelligent BMS, which balances the cells and protects the system from common operational risks, while additional fire safety solutions are also incorporated.

The BOS-G Pro features modular scalability - you can expand capacity as renewable energy consumption or backup power needs grow, without replacing the entire system. Its declared lifespan, measured in thousands of cycles, along with the long warranty, translates to lower energy costs over time and reduced investment risk. Communication via CAN and RS485 facilitates compatibility with hybrid inverters and the construction of off-grid, on-grid, and residential/commercial installations.

Ranking

29 batteries from 20 to 50 kWh

Metric This battery Median Position in class Rank in class

Round-trip efficiency - 95.0% Not published -

Power per kWh 1.11 0.51 Strong · top 13% 2

Cycle life 6000 6000 Typical 2

Weight per kWh 11.6 11.1 Typical 20

Warranty 10 yrs 10 yrs Typical 2

Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

See 44 Deye offers

Specifications

Open datasheet PDF

Usable energy 36.86 kWh What the battery delivers, full to empty

Nominal energy 40.96 kWh What the cells hold

Depth of discharge 90 %

Module energy 5.12 kWh

Modules per stack 5 to 16

Max system capacity 81.9 kWh

Units in parallel 16

Continuous discharge power 40.96 kW 1.11 kW per kWh

Continuous charge power 40.96 kW

Peak discharge power 51.20 kW For 120 s

Max discharge current 100 A

Max charge current 100 A

Peak discharge current 125 A

Cycle life 6000 cycles At 90 % depth of discharge

Capacity at end of life 70 %

Voltage class High voltage

Nominal voltage 409.6 V

Operating voltage 352 to 467 V

Cell technology LFP LiFePO4

Cell management Cobalt-free

Dimensions 1629 × 530 × 602 mm Height × width × depth

Weight 428.0 kg 11.6 kg per kWh

Enclosure IP20 (battery enclosure)

Mounting rack

Operating temperature -20 to 55 °C

Compatible inverters Deye (SUN-50K-SG01HP3-EU-BM4 / SUN-60/70/75/80K-SG02HP3-EU-EM6)

Protocols CAN2.0RS485

Warranty 10 years

Certifications UN38.3CECE-EMCIEC62040CECVDE

Pros and cons

5 positive · 1 caution

What owners get

LiFePO4: >6,000 cycles

LFP cells are reported to withstand over 6,000 cycles at 0.5 C and a 70% Depth of Discharge (DoD) at 25°C, which is significantly better than typical NMC-based storage systems (approximately 3,000-4,000 cycles). In practice, this translates to over 16 years of use with a single cycle per day, resulting in a lower Levelized Cost of Energy (LCOE).

Modularity: 5.12 kWh per rack (19")

Each module provides 5.12 kWh in a standard 19" rack format, allowing for precise matching of capacity to needs and expansion of the system without replacing the entire system. This is an advantage over compact all-in-one units, which do not offer this level of scalability.

10-year warranty + product line active until 2026

Deye offered a 10-year warranty, and the product brochure was updated in January 2026 (v1.0), which confirms that the manufacturer actively supports this product line. This provides the investor with the assurance of ongoing service and technical support throughout the warranty period.

CAN2.0 + RS485 dual-protocol

Support for both communication standards (CAN 2.0 and RS485) ensures native compatibility with a wide range of hybrid inverter ecosystems (including Deye, Growatt, Solis, SMA, and Victron). This eliminates the need for protocol converters, simplifying integration.

Wide operating temperature range: -20°C to +55°C

The certified operating range of -20°C to +55°C allows the system to be installed in unheated boiler rooms or cool garages without risking warranty loss - a significant advantage in a central European climate, where winter temperatures can drop several degrees below zero in technical areas.

Trade-offs

IP20: Intended for indoor use only.

The IP20 protection level only protects against objects larger than 12.5 mm and provides no protection against moisture. Competitive rack-HV systems, such as BYD HVM (IP55), allow for installation in outdoor or humid environments. This limits the flexibility of location - a dry, enclosed technical room is required.

Alternatives

All Deye batteries

Battery Usable Round-trip Power Voltage Difference

Deye BOS-G40 Pro 36.86 kWh - 41.0 kW High voltage You are here

BOS-G40 36.86 kWh - - HV Similar on paper

BOS-G35 32.25 kWh - - HV -4.6 kWh

BOS-G45 41.47 kWh - - HV +4.6 kWh

SigenStor BAT 8.0 system (5 modules) 39 kWh - 20.0 kW - +2.1 kWh, -21.0 kW

SigenStor BAT stack (5 modules) 40.3 kWh - 20.0 kW - +3.4 kWh, -21.0 kW

SigenStor BAT stack (4 modules) 32.24 kWh - 16.0 kW - -4.6 kWh, -25.0 kW

SigenStor BAT 8.0 system (4 modules) 31.2 kWh - 16.0 kW - -5.7 kWh, -25.0 kW

About the BOS-G Pro series

6 answered

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

How many Deye BOS-G Pro modules can be connected, and what is the maximum capacity that can be achieved?

The BOS-G Pro series is modular and scalable - each module has a capacity of 5.12 kWh (100 Ah, 51.2 V). Up to 5 modules can be connected in parallel, resulting in a maximum of 25.6 kWh in a single system. Thanks to the 19-inch rack standard, expansion involves simply inserting another module, without the need to replace the inverter or wiring.

How many cycles does the Deye BOS-G Pro battery last, and what is the warranty?

The manufacturer guarantees at least 6000 full charge and discharge cycles while maintaining 70% of its original capacity (EOL). Deye provides a 10-year manufacturer's warranty, starting from the date of installation, covering manufacturing defects and excessive capacity degradation. With typical use of one cycle per day, this corresponds to more than 16 years of operation.

Why does the BOS-G Pro use LiFePO4 batteries instead of NMC batteries?

The chemistry of LiFePO4 (LFP) batteries is safer thermally than NMC batteries - they do not release oxygen during failure, which significantly reduces the risk of fire. Furthermore, LFP batteries have a higher cycle life and a smaller capacity decrease over time. This translates to a longer lifespan and lower energy costs for the average homeowner over the years, despite a slightly higher initial purchase price.

Which hybrid inverters are compatible with the Deye BOS-G Pro?

The battery communicates via CAN 2.0 and RS485 interfaces, ensuring compatibility with most popular hybrid inverters available on the European market, including the Deye SUN-xK-SG04LP3 model and compatible models from other manufacturers that support high-voltage BMS (Battery Management System) protocols. It is advisable to check the current compatibility list with the installer or distributor before making a purchase.

Does the Deye BOS-G Pro system function properly in low temperatures, such as in an unheated garage during winter?

The specified operating temperature range is from -20°C to +55°C, so an unheated garage in Poland does not pose a problem for the battery's operation. However, it is important to note that at temperatures close to zero, the usable capacity may temporarily decrease - this is a characteristic of lithium-ion batteries, independent of their chemistry. The BMS automatically protects the cells from charging in extreme cold.

Is the Deye BOS-G Pro energy storage system suitable for off-grid (stand-alone) installations?

Yes, the BOS-G Pro can operate in both on-grid and off-grid modes, as well as in a backup mode. The configuration depends on the chosen hybrid inverter - the BOS-G Pro only provides energy storage, while the inverter provides the switching logic. The system is suitable for homes, small businesses, and facilities that require continuous power supply.

Compare with alternative