Deye AI-W5.1-B (6 modules)

27.6 kWh usable LFP Low voltage

Compare with closest alternative Datasheet PDF

Usable (kWh)

27.60

Typical for its class

Round-trip (%)

Not published

Power (kW)

12.8

Weak · bottom 3%

Cycles

6000

Typical · median 6000

Weight (kg)

339.5

Typical · median 310.0 kg

Warranty (yrs)

Typical · median 10 yrs

The Deye AI-W5.1-B series are low-voltage modular energy storage units designed for effortlessly building home or business energy banks without unnecessary complexity. The key advantage lies in the LiFePO4 (LFP) chemistry without cobalt - practically, this means superior thermal safety, stable performance, and a long service life compared to many NMC solutions, especially during intensive cycling.

What sets it apart is its flat, stackable structure facilitating rapid installation and expansion, along with an intelligent BMS that manages cell balancing and protects the battery pack during both charging and discharging. The series is engineered for long-term operation - high cycle counts and a 10-year warranty translate to predictable energy costs and reduced risk of replacement after a few seasons.

The AI-W5.1-B can be scaled by adding more modules, increasing capacity as needs grow (e.g., with the addition of a heat pump). The solution is also compatible with hybrid inverters, making it an excellent choice for PV systems, backup power setups, and off-grid applications.

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 0.46 0.51 Weak · bottom 3% 16

Cycle life 6000 6000 Typical 2

Weight per kWh 12.3 11.1 Typical 21

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 27.6 kWh What the battery delivers, full to empty

Nominal energy 30.72 kWh What the cells hold

Depth of discharge 90 %

Module energy 5.12 kWh

Modules per stack 1 to 6

Max system capacity 30.7 kWh

Units in parallel 6

Continuous discharge power 12.80 kW 0.46 kW per kWh

Continuous charge power 12.80 kW

Peak discharge power 18.43 kW For 10 s

Max discharge current 250 A

Max charge current 250 A

Peak discharge current 360 A

Cycle life 6000 cycles At 90 % depth of discharge

Capacity at end of life 70 %

Voltage class Low voltage

Nominal voltage 51.2 V

Operating voltage 43 to 58 V

Cell technology LFP LiFePO4 (LFP)

Cell management Cobalt-free

Dimensions 1974 × 720 × 255 mm Height × width × depth

Weight 339.5 kg 12.3 kg per kWh

Enclosure IP65 (after stacking)

Mounting wall

Cooling passive

Operating temperature -20 to 55 °C

Protocols CAN2.0RS485

Warranty 10 years

Warranted throughput 16.0 MWh Cover ends at the years or this, whichever first

Certifications UN38.3IEC62619CEUKVDE2510-50CEI 0-21CE-LVDCEC

Pros and cons

5 positive · 2 caution

What owners get

LFP with a lifespan of at least 6000 cycles at 70% of its expected end-of-life (EOL).

Certified lifespan of ≥6000 cycles while maintaining 70% capacity (EOL) translates to over 16 years of operation with a cycle per day, which is a significant advantage over NMC batteries, which typically achieve 3000-4000 cycles at the same level of Depth of Discharge (DOD), and also over the Pylontech US5000 (which offers a 10-year warranty with only 60% EOL).

Round-trip efficiency ~95.5%

The official datasheet specifies a charging/discharging efficiency of 95.5%, placing the series among the top-performing LV batteries. For comparison, the BYD Battery-Box Premium LFP boasts ~96%, which represents a minimal difference that is practically imperceptible in prosumer installations.

Scalability from 5.12-184 kWh without needing to replace the core

The modular architecture allows for the connection of up to 36 modules (6 clusters × 6 modules) without replacing the PDUs or the main cabling. Adding another 5.12 kWh is a plug-and-play operation, making the series a practical choice for later expansion of the installation with a heat pump or EV charger.

IP65 rating and operating temperature range: -20°C to +55°C

The IP65 protection allows for outdoor installation (e.g., in a garage or shed), and the specified operating temperature range of -20°C to +55°C is suitable for typical European winter conditions without the need for a heated enclosure - a feature that is often only available in more expensive models in competing series.

10-year manufacturer's warranty (starting from 2023)

The series released in 2023 comes with a 10-year warranty, provided that the nominal capacity remains ≥70% - a standard higher than, for example, Growatt ARK (10 years / 60% EOL), and comparable to BYD Battery-Box HVS/HVM in this regard, with a lower initial capital investment requirement.

Trade-offs

The 48V LV architecture limits the individual power output.

As a low-voltage (48V) storage system, a single 5.12 kWh module offers a maximum continuous power of approximately 2.56 kW (0.5C). Installations requiring >10 kW of instantaneous power must connect multiple modules in parallel with an LV inverter. Alternatively, high-voltage systems (e.g., BYD HVM/HVS, Huawei LUNA2000) can achieve the same result with a simpler DC topology.

Full integration of the BMS primarily with Deye inverters

Communication with the BMS via CAN/RS485 is best verified using Deye SUN2000/SG-series inverters. When using SMA, Fronius, or Victron inverters, integration requires additional configuration and may not always provide the full range of diagnostic data, which can make monitoring in multi-inverter systems more challenging.

Alternatives

All Deye batteries

Battery Usable Round-trip Power Voltage Difference

Deye AI-W5.1-B (6 modules) 27.6 kWh - 12.8 kW Low voltage You are here

AI-W5.1-B (5 modules) 23 kWh - 12.8 kW LV -4.6 kWh

BOS-G30 27.64 kWh - - HV high voltage

ECS4300H-H7 26.13 kWh 95.0% - HV -1.5 kWh, high voltage

SigenStor BAT stack (3 modules) 24.18 kWh - 12.0 kW - -3.4 kWh, -0.8 kW

SigenStor BAT 8.0 system (4 modules) 31.2 kWh - 16.0 kW - +3.6 kWh, +3.2 kW

SigenStor BAT 8.0 system (3 modules) 23.4 kWh - 12.0 kW - -4.2 kWh, -0.8 kW

BOS-G25 23.04 kWh - - HV -4.6 kWh, high voltage

BOS-G25 Pro 23.04 kWh - 25.6 kW HV -4.6 kWh, high voltage, +12.8 kW

About the AI-W5.1-B series

6 answered

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

How many Deye AI-W5.1-B modules can be connected, and what is the maximum system capacity?

The individual Deye AI-W5.1-B module has a capacity of 5.12 kWh. A single stack can accommodate up to 6 modules, resulting in a total capacity of 30.72 kWh. Furthermore, it is possible to connect up to 6 clusters in parallel, providing a total capacity of up to 184 kWh. This makes the series ideal for both small residential installations and larger commercial systems, which can be scaled to meet increasing energy demands.

What is the warranty on the Deye AI-W5.1-B energy storage system, and how many charge/discharge cycles does the battery last?

The Deye AI-W5.1-B comes with a 10-year manufacturer's warranty. The LiFePO4 batteries used in this series are rated for at least 6000 charge and discharge cycles. This means that with a single cycle per day, the battery can reliably last for over 16 years of operation before its capacity drops to the warranty level - making it one of the most durable options in its price range.

Does the Deye AI-W5.1-B function properly in low temperatures, and can it be installed in an unheated garage?

Yes, the AI-W5.1-B series supports a temperature range of -20°C to 55°C and features an IP65-rated enclosure, which means protection against dust and water jets. Therefore, installation in an unheated garage or storage room is possible. However, it is important to note that at very low temperatures, the usable capacity of the LFP battery may decrease slightly - the built-in BMS then protects the cells from damage.

Which hybrid inverters are compatible with the Deye AI-W5.1-B battery storage system?

The AI-W5.1-B series is primarily designed for use with hybrid inverters from Deye (including models such as SUN-XK-SG01LP1 and SG04LP3), which communicate with the battery via a dedicated BMS interface. The series also supports AC coupling, which allows for integration with inverters from other brands. However, it is advisable to verify the specific firmware version of the inverter before purchasing to ensure full compatibility and proper monitoring functionality.

What are the key differences between the LiFePO4 technology used in the Deye AI-W5.1-B compared to NMC batteries used in other storage systems?

The LiFePO4 (LFP) cells used in the AI-W5.1-B are cobalt-free and exhibit significantly higher thermal stability compared to popular NMC cells - the risk of thermal runaway is much lower in them. LFP also tolerates deep cycling better than NMC, which directly translates into the stated 6000 cycles and long lifespan. A drawback of LFP is its slightly lower energy density, which means that the modules are slightly heavier for the same capacity.

What does the installation and expansion of the Deye AI-W5.1-B system entail - is a specialist required?

Deye AI-W5.1-B modules have a flat, stackable design intended for placement on the floor - they do not require drilling into the wall or complex wiring between modules. Expansion involves adding additional units to the stack. Despite the simple mechanics, connecting the batteries to the inverter and configuring the BMS require Level 1 Safety (SEP) electrical qualifications, so installation should be carried out by a certified renewable energy installer.

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