Knowledge base / Brands / Huawei FusionSolar / BackupBox-B0/B1

Huawei FusionSolar · Solar inverter model

BackupBox-B0/B1

Huawei BackupBox-B0 and BackupBox-B1 provide automatic grid and backup changeover for compatible single-phase L1 and three-phase M1 battery systems.

Specifications

SpecificationValue
Typebackup changeover box
Supply phasessingle-phase grid for B0; three-phase grid for B1; single-phase backup output
Maximum backup apparent power (kVA)5.0 for B0; 3.3 for B1
Maximum output current (A)22.7 for B0; 15.2 for B1
Switchover time (s)under 3
Dimensions (mm)400 × 350 × 130
Weight (kg)11
Compatible invertersSUN2000 KTL-L1 for B0; SUN2000 KTL-M1 for B1
Warranty (years)2
IP ratingIP65
Operating-temperature range (°C)-20 to 45

Huawei BackupBox-B0 and BackupBox-B1 are automatic changeover units for compatible Huawei solar and battery systems. They switch connections but do not store energy or perform the inverter’s power conversion. A compatible inverter and LUNA2000 battery provide those system functions. B0 matches SUN2000 KTL-L1 and B1 matches KTL-M1.

B0 and B1 limits

The two boxes do not provide the same backup output. B1 takes a three-phase supply but its protected output remains single phase and has a lower published limit than B0. The word three-phase describes the grid side of B1, not a three-phase protected output.

Changeover, inverter and battery roles

BackupBox is not a battery or inverter. It changes the connection state so the compatible inverter can supply selected loads while isolated from the grid. The complete system still needs a compatible LUNA2000 battery and a compliant islanding design.

B0 and B1 are not interchangeable. The grid phase arrangement, inverter family and backup rating differ.

Huawei’s current residential comparison also presents SmartGuard. Its specifications must not be applied to an installed BackupBox.

BackupBox warranty category and UK supply status

Huawei’s May 2026 European policy places BackupBox in its accessory warranty category, subject to the sales contract. Both codes appear in Huawei’s April 2024 UK PSTI (Product Security and Telecommunications Infrastructure) statement, whose separate period concerns product security. Backup equipment remains in the global catalogue, but current UK new supply for both boxes is unconfirmed.

Reference type

Solar inverter model

Last reviewed

23 Jul 2026

Current status

UK new-supply status is unconfirmed.