Best-in-class safety and efficiency


The Nilar Battery Management System (BMS) monitors, controls and protects the batteries to maintain a long service life. The fine-tuned management system optimizes battery operation for best-in-class reliability, safety and efficiency at all time

BMS Function Overview


System Architecture 

The Battery Management System (BMS) controls and oversees the system in its combination of software and hardware. The BMS consists of the BMS Master Unit (BMU) which has control over the system, the String Cluster Unit (SCU) which handles up to two strings, the Integrated Monitoring Unit (IMU) which monitors the battery´s data and transfers it upwards in the system, the Fan Control Unit (FCU) which controls up to 10 fans and a Humidity LED Interface (HLI) that measures the environment conditions and acts as an interface through its LED.  

The BMS monitors and manages the operation of the batteries for the well-being of the system and its environment. Remote access is needed for system support, troubleshooting, software updates, and data logging as a source for system support and troubleshooting. 

BMS Circuit boards

Battery Management Unit

The Battery Management Unit (BMU) is the main interface between the batteries and an external Energy Management System (EMS). It gathers data from the batteries and makes sure they are operated within their limits. The EMS can communicate with the BMU when it requires the batteries to perform certain actions, such as disconnect or connect, as well as read operational data from the batteries.

String Control Unit

The SCU connects and disconnects the strings, measures current going in and out of the string, measures the battery string voltage and collects data from the IMU. It also handles control and power supply to the FCU and IMU. The SCU is a part of the safety redundancy system within the Nilar BMS.

Integrated Monitoring Unit

The Integrated Monitoring Unit (IMU) comes pre-installed on each battery pack. It measures individual module voltages, the temperature of the battery pack and pressure within the battery. These values are then reported to the SCU and BMU which in turn monitor and performs certain actions to ensure the battery is kept within safe operation. The IMUs are connected to the SCU via an ethernet port which provides all the data connection and power supply necessary.

Fan Control Unit

The FCU is used to control fans for cooling of battery packs. Each pack can be cooled by a separately controlled fan. The FCU can control up to 10 fans and uses a PWM control to monitor and control the speed of the fans depending on cooling requirements.

Humidity and LED Interface

The HLI board is designed to communicate through its on-board RGB LEDs to convey actions that the BMS is currently taking, and if any attention is required from an external party. It includes a tactile switch and measures the ambient temperature and relative humidity surrounding the card. The measurements and inputs are sent to the BMU which monitors the data and acts on user input.