ZZT-ZBT5K-BDU
Battery Distribution Unit (BDU) for ZCS Azzurro high voltage storage systems using 5.1 kWh ZBT 5K modules. It is the base unit of the tower, housing the BMS, the DC protection devices and the link to the inverter.
IP65 rated, inverter connection cables included. One BDU is required per battery tower, with 1-4 modules per tower.
The ZZT-ZBT5K-BDU is the Battery Distribution Unit of the ZCS Azzurro high voltage storage systems. It is not a storage module: it is the base unit of the tower, housing the battery management system (BMS), the DC protection devices and the interface to the hybrid inverter.
What the BDU does in a storage tower
In HV systems the battery modules are stacked in series until they reach the inverter's working voltage. For the tower to operate, a unit is needed to monitor the voltage, current and temperature of every module, manage balancing and open the circuit in the event of a fault: that is precisely the BDU's job. The power and communication cables to the inverter also run from it and are supplied with the unit.
As a result, every battery tower requires one — and only one — BDU, regardless of how many modules are stacked above it.
ZZT-ZBT5K-BDU technical specifications
| Function | Battery distribution and management unit (BDU/BMS) |
| System | ZCS Azzurro high voltage storage |
| Compatible modules | ZBT 5K, LiFePO4 chemistry, 5.1 kWh each |
| Modules per tower | 1 to 4 |
| BDU per tower | 1 (mandatory) |
| Towers per inverter | Up to 2 |
| Maximum system capacity | Around 40 kWh with two full towers |
| Ingress protection | IP65 |
| Supplied with | Inverter connection cables included |
| Dimensions | 708 × 170 × 200 mm |
| Weight | Approximately 20 kg |
How the system is put together
- One BDU at the base, closing the tower towards the inverter.
- One to four ZBT 5K modules stacked above it, 5.1 kWh each.
- A ZCS hybrid inverter rated for high voltage storage, managing charge and discharge.
To go beyond the capacity of a single tower, a second complete tower is added alongside — with its own BDU. That is the most common sizing mistake: ordering extra modules without the second base unit.
Installation notes
Installation and commissioning must be carried out by qualified personnel following the manufacturer's manual. The IP65 rating allows mounting in demanding environments, but the operating temperature limits and the clearances specified by the manufacturer must still be respected. Compatibility with the inverter should always be verified against the specific model before ordering.
Frequently asked questions
Does the BDU contain cells and store energy?
No. The BDU stores no energy: it is the management and distribution unit at the base of the tower. Capacity comes from the ZBT 5K modules stacked above it, 5.1 kWh each.
How many BDUs do I need for four modules?
Just one. A single BDU manages the whole tower, from one module up to four. A second BDU is only needed when a second battery tower is added to expand capacity further.
Can modules be added later?
Yes, the system is modular and expandable up to four modules per tower. The expansion should be planned with the installer: the compatibility of the new modules, the condition of those already in service and the manufacturer's guidance on mixing modules of different ages all need checking.
Are the inverter cables included?
Yes, the BDU is supplied with the cables for connection to the inverter. Cabling between the modules in the tower, if not included with the modules themselves, and any protection devices required by the system design still need to be allowed for.
Does it work with any hybrid inverter?
No. The system is intended for ZCS Azzurro hybrid inverters designed for high voltage storage. Before ordering, compatibility with the specific inverter model and with the planned tower configuration should be verified in the documentation.