Deye AI-W5.1-B (1 module)
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
Price offers
| Shop | Country | Price | Per kWh | Stock | Offer updated | Link to shop |
|---|---|---|---|---|---|---|
| Sklep Soltech | Poland | 3 864 zł net | 840 zł/kWh | Not stated | 4h ago | Visit shop |
| Master Energy | Poland | 4 858.50 zł incl. VAT | 1 056.20 zł/kWh | In stock | 3h ago | Visit shop |
Specifications
Pros and cons
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).
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.
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.
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.
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.
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.
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
About the AI-W5.1-B series
These answers cover the whole series. Where a figure differs, the specification above is this model's own.