5/8/2023 0 Comments Battery monitor ics![]() ![]() To be effective, these power-management subsystems must: 9-1 shows the basic power-management subsystem employed in a battery-based system. One reason for this growth has been the availability of batteries and power-management ICs that provide the required support for increasingly complex electronic systems. Use of battery-powered systems have expanded as consumers have migrated to portable phones, MP3 players, digital cameras, and more. I will build a test circuit and evaluate the BQ34Z110 IC as this looks the most promising.This articles is part of the Power Management Series in the Power Management section of our Series Library. Battery monitoring could also be implemented using a microcontroller, which I will also be looking into, but to get a reasonable accuracy then a better resolution ADC would be required (rather than the 10-bit ADC incorporated within most microprocessors. There is only one dedicated lead-acid battery monitoring IC that I have found so far. There are a lot of these due to the number of devices which use Li-Ion technology and the stricter charge/discharge requirements of Li-Ion technology. These include BQ2019, ENA2031, S-8225 and plenty of others. ![]() There are a number of other ICs when you search for ‘Battery Monitor IC’, but nearly all of them relate to Li-Ion or NiMH technology and are designed for use in small personal products, such as laptops and phones. But it is only single direction, hence two would be required for correct battery monitoring. This can be used to measure power flow and hence calculate the state-of-charge of the battery. This is not specifically a battery monitor IC, but is a power monitor. Maximum voltage across the shunt resistor is 102mV 12 bit resolution for Current and Voltage. £5.52 + VAT from Digi-KeyĠ-80V input voltage. I will build a prototype circuit board for testing and evaluating this device. This device seems perfect for monitoring battery banks in the scale I am interested in. Uses a 5milliOhm to 20milliOhm shunt resistor. Can add an NTC thermistor for temperature measurement. Works with batteries from 4-64V and battery banks greater than 65Ah. It uses a special ‘Impedance Track’ (proprietary) algorithm from TI. This IC is designed especially for Lead-Acid batteries. There are a number of applications notes relating to this IC “Going to production”, “ Configuring the Data Flash” and “ Using the IC for sealed lead-acid batteries“. The voltage can be measured with a potential divider to keep it within the range of 5.5V max. He mentions that the shunt resistor from the data sheet is theoretical 30mOhms, and with other shunt resistors different current ranges can be measured, as long as the maximum shunt voltage is <80mV. Maximum battery capacity is 7000mAh, hence it is not suitable for larger off-grid systems.Įdit 20/1/15: Thanks to Doug for emailing about the use of the IC in 12V battery monitoring systems with higher currents. Uses an I2C interface.Ĭurrent is measured through a shunt resistor, with a maximum input of +/- 80mV. It measures Voltage, Current and Temperature with 12/14 bit accuracy and a 32kHz time base. While not useful for a large lead-acid battery bank, this might be useful for some form of small Li-Ion solar lamp. These are designed for small portable consumer electronics with Li-Ion technology batteries. There is an application note for using this IC here. Note: Prices were checked in November 2014 and might not be accurate. There has been a recent article on the need for monitoring state-of-charge and health of batteries here. ![]() ![]() If you know of any other ICs that might be useful, please add a comment. Here I will review the ICs I have found and include any data on testing them. I have managed to obtain a few samples for various battery monitoring ICs and also found the data sheets for others. The addition of battery monitoring capability would be one of the most useful additions. This ties in with my open-source charge controller project and also the battery monitor project, which has been on my list of things to do for a number of years. I wanted to review the few that I had heard about and see how applicable they might be for an off-grid battery monitor. There are also a number of ICs (intgrated circuits) which can perform this function. boats) and are relatively high cost (too high to include within a small off-grid power supply system). There are a number of ready-built products already available, mainly for the recreational vehicle market (eg. Accurately monitoring lead-acid battery state-of-charge would help with the long-term sustainability of off-grid renewable energy systems. ![]()
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