Shunt-based management system for lithium-ion batteries

Paul Boughton

Isabellenhütte's new IB4 battery management system is designed for four-cell lithium ion batteries with individual cell voltages of up to 5V, and was developed in co-operation with the company’s Braunschweig-based development partner I+ME Actia. It features 300A current measurement, 1,000A pulse and highly precise resolution of 10mA, as well as a low measurement error range of just 0.4 per cent of the measured value. The unit’s power consumption is very low, 2.5mA when the master switch is on and 1.5mA when it is switched off.

Numerous interfaces for communication, measurement value recording, and control allow the IB4 to be deployed flexibly. For example, two push switch inputs provide the opportunity to query the state of charge at the touch of a button. There are various analogue inputs, including those for the measurement of cell temperature, battery mode planning, total voltage, and hardware monitoring of cell voltages. There are also control outputs for a bistable relay, five LED charge indicator displayed, as well as two optional low-side switching outputs for special applications, eg heat monitoring. The IB4 from Isabellenhütte has an isolation voltage of 200V. The current sensor is an 100µOhm shunt.

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