Linear Technology AN112 Application Note Battery Stack Voltage Measurement

About this manual

The document addresses the "battery stack problem," where measuring individual cells in series-connected batteries is difficult due to high common-mode voltages that exceed standard component breakdown limits. The proposed solution uses a transformer-based sampling voltmeter to galvanically isolate the measurement circuit from these high potentials, allowing the use of conventional low-voltage techniques.

What's inside

• The Battery Stack Problem
• Transformer Based Sampling Voltmeter
• Detailed Circuit Operation
• Multi-Cell Version
• Automatic Control and Calibration

Frequently asked questions

What is the circuit accuracy at 25°C over a 0V to 2V battery range?

The circuit achieves an accuracy of 0.05% with a drift of 120ppm/°C.

What is the absolute maximum cell voltage that can be measured using the processor-driven circuit?

The absolute maximum cell voltage that can be measured is 3.396V.

What is the accuracy of the processor-driven circuit over a 0V to 2V input range at 25°C?

The accuracy is 1mV with drift dropping to less than 50ppm/°C.