Battery backup units


The needs

The development of broadband telecommunications networks led to a widespread diffusion of decentralized network nodes (e.g. miniDSLAM VDSL2, MSAN, DPU...), typically installed in street side cabinets.

These network devices require a 48-60Vdc power supply obtained in different ways, the most common of which is a direct connection with the electric grid.

The continuity of the 48-60Vdc power supply, provided by dedicated AC/DC converters, is a fundamental requirement for the reliable provision of network services offered by telecommunications operators. Long term interruptions of power supply lead to a complete disservice for all users connected to the involved affected node.

The restart times of telecommunications system can take up to several minutes before the complete recovery of all active services, and this helps to better understand the impact of even a brief interruption.

On these premises, fixed network operators started to search specific solution that ensure the continuity of the network node power supply at 48-60Vdc even with long term interruptions of electrical supply. The continuity of the 48-60Vdc power supply is ensured by rechargeable batteries backup units with capacity and current suitable for the application. These units are located after the AC/DC converters and power feed the network devices without any interruption even when the main power source fails.

The challenges

  • High energy density per-unit volume (reduced installation space)
  • Integrated automatic charging and maintenance system
  • Automatic and instantaneous switching of the power-path
  • Wide range of operating temperatures (street side cabinets exposed to the sun and bad weather)
  • Resistance to mechanical stress (vibrations on street installations)
  • Wireless access to status information and diagnostic and statistical data on discontinuities
  • Possibility of clustering connection and remote control/monitoring

The realization

The BBU series devices are DIN-rail battery backup units, able to ensure the continuity of DC power supply from 24 up to 60 Volts. BBU units are available with lithium-ion (Li-Ion) and lithium iron phosphate (LiFePO4) batteries, and with capacities up to 190Wh and a maximum deliverable power of 500W. Automatic charger and power-path switching integrated in the device. Thermal control and integrated BMS for balancing and managing the charging/discharging processes of individual battery pack cells. Integrated NFC tag for operational parameters, statistics and events history of IN and OUT faults reading. Indication of local (LED and TAG NFC) and remote alarm through signalling contact.Possibility of cluster connection with other BBU units via RS485/MODBUS interfaces in order to extend discharge autonomy through automatic sequential dispensing. Remote control and monitoring through interconnection to a dedicated NB-IoT connectivity module, usable on a single unit BBU or on a cluster.

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