A-BMS – Active Battery Management System for backup applications
Scope
These solutions are intended to support 48V stationary backup batteries serving telecom or other critical loads.
Batteries may be any lead-acid type, consisting of 12 or 6 volt blocks with capacity in the range of 100 – 250 AH or of 2 volt cells with capacity up to 2400 AH.
Battery support is complemented with complete remote monitoring and control of the equipment activity over the internet, with organization level battery asset management.
Optional capability is provided to extend remote monitoring and control to other installation equipment.
Battery support includes:
- Individual trickle charge of the blocks during float, approximating shelf storage conditions
- Active battery equalization
- Protection against cell over-charge and over-discharge
- Periodic battery testing, including optional lossless discharge test
- Optional control of diesel generator
Target benefits
- Battery life extension beyond the typical service life limits stated by the manufacturer for the actual operating conditions (number of cycles and temperature), approaching shelf storage life.
- Reduction of energy consumption during float.
- Elimination of On-site preventing maintenance of backup batteries
- Early detection upcoming faults to individual battery blocks.
- Accurate remote view of battery SOH and ageing
- Capability for remote full battery test (including discharge test)
- Detected faulty battery cells (or cell blocks), may be individually replaced. It won’t be necessary to replace the entire battery
Functional description (concept)

Our Active Battery Management systems, for backup applications, control the trickle current individually for every cell (or cell block), according to its own detected specific needs. This eliminates the unnecessary stresses (*link*) and allows the battery life to extend beyond the manufacturers service life specifications, almost up to the shelf storage life limit.
During charging, the bms control is bypassed, allowing the battery to charge. During the floating state, the system (bms) takes control and enters the battery support mode: The battery is disconnected from the charger and the OCV and internal resistance are measured periodically for all the cells (or cell blocks). Trickle current is applied independently to each cell (or cell clock) by its dedicated charger, whenever it is necessary to compensate for its self-discharge. User triggered lossless full discharge test may be performed if desired, for ultimate battery test and actual capacity measurement.
This battery support mode covers usually the 95-99% of the battery life, between power outages and is exactly equivalent to shelf storage in ideal fully charged conditions, without any stress at all, also eliminating almost completely the power consumed during float. This is the reason for the remarkable improvement in battery service life.
During battery discharge, probably while a power outage event, battery is protected against over-discharge. A hardware output signal is generated, when the voltage of a cell (or cell block) falls below its limiting value, to activate the LVD system of the charger or to activate the optional Load Disconnect module of the bms.
During charging, the battery is also protected against overcharge, by entering the battery support mode when it is fully charged.
Detailed battery status and battery management equipment activity reports are sent over the IoT to the central server for further processing and distribution.

Our Remote Monitoring and Control Platform running on our central meeting point server is a seamless extension of the software running on the Active Battery Management Equipment. It performs the following tasks:
- Collects the status reports from the individual BMS’s are stores them to the Battery data Database
- Analyzes battery data and detects faulty cells and strings. On any such detection, it issues appropriate alarms for early cell replacement
- Analyzes further the ageing course of the batteries and generates end-of-life and replacement forecasts
- Checks the BMS operational integrity for equipment faults and updates automatically the firmware to the latest version
- Provides the link between batteries and battery owners
- Battery owners and battery owner organization employees join the Remote Monitoring and Control Platform, as users belonging to the specific battery owner and according to a manageable matrix of rights, using commercial web-clients and access the Battery Management Interface

The Battery Management Interface is a seamless extension of the Remote Monitoring and Control Platform for the user side.
It is a very flexible and user friendly tool, accessible by the stuff of the Battery owner organization, through web-clients, from PC’s, tablets and Smart-phones. It provides to the users the following functionalities:
- Organization-site-level overview of real-time battery status (including BMS equipment status), also with geographic visualization
- Site-level real-time battery parameter and BMS activity analytic presentation extending down to cell level.
- Manual control of all the BMS equipment features, in order to perform special tests and cell treatments manually (for qualifying users only, according to their rights levels)
- Site-level history data presentation for batteries, down to cell level and for BMS activity
- Real-time alarms
- Alarm history
- Quick data trend analysis for all battery parameters, down to cell level, extending to the entire battery life
- Predictive reports for battery life and replacement scheduling
- Battery replacement history
- System Configuration settings control (BMS equipment setup, threshold settings, system preferences etc.)
- User management (user creation, user data editing, user rights level control)
Physical description of the solutions
Two different versions of the backup battery active management system equipment are available according to the exact battery format: single cell or multi-cell blocks.
Active battery management system equipment for backup batteries consisting of 12/6 V blocks.

The product is a distributed system consisting of a central control unit and one string control unit for every string.
The string control unit is inserted between the negative pole of the string and the negative bus (-48 Volt). It includes for each 12/6 V block, a high accuracy measurement system for the detection of its electrical and thermal conditions (for SOH evaluation) and also a high efficiency 2-way converter (charger/discharger) to perform, whenever necessary, charge exchange for trickle charging and equalization. It also includes a special power converter for discharge test of the string.
The central unit supervises and controls the entire battery through the individual string control units. It connects over the internet to the central server and provides the remote monitoring and control to the battery owners. Special peripheral interface adapter units may be connected to the central unit, to extend the remote monitoring and control to other pieces of equipment (rectifiers, air conditioners, PV chargers, diesel generators etc.) installed at the same site with the batteries.
Active battery management system equipment for large backup batteries consisting of single cells.

The product is a distributed system consisting of a central control unit and for every string one string control unit and twelve cell modules.
The string control unit is inserted between the negative pole of the string and the negative bus (-48 Volt).
The cell modules are mounted on the cells. Each cell module serves two adjacent cells. It includes for each cell a high accuracy measurement circuits for the detection of its electrical and thermal conditions (for SOH evaluation) and also a high efficiency 2-way converter (charger/discharger) to perform, whenever necessary, charge exchange for trickle charging, equalization and discharge tests.
Every string control unit collects and processes the data from the cell modules of the same string, determines the SOH of the cells and schedules for every cell any charge exchange necessary for trickle charge, active equalization and discharge test.
The central unit supervises and controls the entire battery through the individual string control units. It connects over the internet to the central server and provides the remote monitoring and control to the battery owners. Special peripheral interface adapter units may be connected to the central unit, to extend the remote monitoring and control to other pieces of equipment (rectifiers, air conditioners, PV chargers, diesel generators etc.) installed at the same site with the batteries.
The string control units and the cell modules are connected to the central unit through an optically isolated modified RS485 bus, physically implemented by daisy-chaining the modules with the supplied wiring.