ADI’s Battery Management IC Hopes to Strengthen Runtime for Li-ion Batteries
Combining fuel gauge techniques in its ModelGauge m5 technology, ADI aims to improve Li-ion battery health and life with its latest battery management IC for consumer applications.
The name of the game in today's portable electronic devices is battery life. A simple subject, yet the factors that affect battery life are intricate and plentiful.
One aspect that largely influences the health and lifetime of a battery is the battery management system (BMS).
An example BMS block diagram for consumer electronics. Image used courtesy of Renesas
This week, Maxim Integrated, acquired by (and is slowly merging) Analog Devices (ADI), released a new battery management IC that they claim can provide longer battery run-time for lithium-ion batteries, specifically for consumer applications.
This article will delve into the new IC and the technology ADI implements to achieve longer battery life, like its battery fuel gauge technology and ModelGauge.
Battery Fuel Gauges
One important component of a battery management system is the battery fuel gauge, which is the part of the system that estimates the amount of the charge remaining in a battery.
Old school fuel gauges worked using a technique called coulomb counting, which would aim to measure the current in the power path using a sense resistor at the output. By integrating the current over time and subtracting from the theoretical maximum capacity, coulomb counting provides a rough estimate of how much charge remains in a battery.
This technique is good for its fast response time, but one of its major downfalls is the wasted current that comes from using a sense resistor.
Another method for fuel gauges is to measure the open-circuit voltage of the battery.
Estimating state of charge using an open circuit method. Image used courtesy of ADI
In many popular battery chemistries, the battery's open-circuit voltage is directly proportional to its state of charge (SOC). That is to say that the battery voltage is high at full charge and decreases deterministically (though not linearly) as the charge decreases. This method requires precise battery characterization but is beneficial in that it doesn't waste power via a sense resistor.
Hoping to utilize a blend of both fuel gauge techniques, ADI has created a new battery management IC.
Best of Both Techniques: MAX17330
Today ADI announced their new battery management IC, the MAX17330.
Functional diagram of the MAX17330. Image used courtesy of ADI
The new IC, explicitly designed to increase battery health and lifetime in Li-on-powered consumer electronics, leverages integrated fuel gauge technology.
The gauge technique is called ModelGauge m5, a proprietary fuel gauge technique using a combination of open-circuit and coulomb counting. By using this blend of techniques, ADI claims to achieve 40% more accurate state-of-charge readings without the need for battery characterization.
This accurate reading also translates into a 20% more accurate charging with a higher top-off charge.
Along with battery SOC, the MAX17330 includes internal circuitry to monitor the voltage, current, and temperature. With these functions, the IC can protect against over/undervoltage, overcurrent, short-circuit, over/undertemperature, and internal self-discharge.
According to ADI, the MAX17330 significantly extends device run-time compared to similar products while also providing monitoring of internal cell self-discharge hazards. This IC also comes in a decreased package size, which ADI also claims is 36% smaller than competitors.
Lately, when you hear about BMS and battery management, in general, people are referring to vehicles. However, with an increase in battery-powered consumer electronics, extending battery life is vital.
This new IC from ADI claims to do that while also improving battery healthy and decreasing package size, hopefully enabling a future with smaller, safer, devices with a long time in between charges.
Interested in other battery news? Read on in the articles down below.