Deye SUN-BK250-2.56KWH-EU-AM4-32L2.5kW all-in-one micro storage system with 2.56kWh LiFePO4 battery

Overview

SUN-BK250-2.56KWH-EU-AM4-32L is the largest model of Deye's SUN-BK 2.56kWh micro hybrid storage series: a 2500W single-phase hybrid inverter and a 2.56kWh LiFePO4 battery in one IP65 unit of 32kg. Four MPP trackers, one module each, take 32A per input and up to 5760W of PV access power. It runs grid-tied for self-consumption, off-grid or portable with a backup socket that switches in 4ms or less, or AC-coupled to an existing balcony system. Capacity grows by stacking AE-F2.56 batteries, and up to three units can work in parallel.

• 800–2500W AC, 2.56kWh LiFePO4 battery built in
• 4 MPPT, up to 5760W PV access (-32L)
• ≤4ms switchover to off-grid backup
• Stack up to 5 batteries, up to 102.4kWh
• Up to 3 units in parallel, 7.5kW
• IP65, Wi-Fi, Bluetooth, LoRa, 10-year warranty

How it works

Each unit contains a single-phase hybrid inverter, four MPP trackers for one PV module each and a 2.56kWh LiFePO4 battery of 51.2V nominal. Five power ratings from 800 to 2500W are offered, all with 2500W off-grid power and twice the rated power for 10 seconds. The -18L versions accept 18A per tracker and up to 4400W of PV access power, the -32L versions 32A and up to 5760W, within a 20–55V tracking range and 60V maximum.

Key features

Deye describes three operating modes: grid-tied self-consumption, off-grid as standalone or portable storage, and AC coupling to add storage to an existing balcony PV system. The backup socket switches to battery within 4ms. Six time-of-use periods, a full-charge mode and dynamic-price optimisation through Deye Cloud are available, and export can be limited to zero or to a set value of up to 1000W where local rules require it. The battery is rated for 6000 cycles or more.

Installation and compatibility

Up to four AE-F2.56 expansion batteries stack under the unit, and up to 8 clusters connected by cable reach 40 batteries or 102.4kWh. Up to three units can run in parallel for 7.5kW on one phase or as a three-phase system. Keep 10mm from the rear wall and 300mm at the front, sides and top. A Type 2 SPD must be installed on the grid side; without it Deye allows only off-grid use or on-grid use without backup loads.

Each unit needs its own breaker, with up to 20m of external AC cable, and loads must not be connected between breakers of different units. Zero export uses a wired CT on single-phase installations near the distribution box, or the optional wireless smart meter SUN-SMART-CT02-L with CTs, single- or three-phase. Listed grid regulations include VDE 4105, CEI 0-21, EN 50549-1, G98, C10-11 and UNE 217002.

Monitoring and settings

Setup and monitoring run in the Deye Cloud app over Wi-Fi, with local Bluetooth control for offline use and LoRa between system components. The LED display shows PV, battery, grid, load and backup power, and a USB output can be switched or timed out in the settings. RS485, CT, parallel and load ports are factory options that must be chosen when ordering. Operating range is -10 to 55°C, or -20°C with the optional heating. The warranty is 10 years.

Questions and answers