Why choose Nordic's fuel gauge solution?
Estimating battery state of charge isn’t new - but doing it accurately, efficiently, and at low cost has always involved tradeoffs. To be truly useful in modern IoT and consumer devices, a fuel gauge must check three boxes: high accuracy, ultra-low power consumption, and minimal system cost. Until now, you could only chose two.
Nordic takes a smarter approach. Our algorithm-based fuel gauge method combines a battery model with real time PMIC voltage, current, and temperature data. The algorithm runs directly on the host controller. The result is the best of all worlds - accuracy comparable to high-end solutions, zero power draw during sleep, and virtually no added cost. With only a few kilobytes of flash required and no licensing fees, Nordic’s fuel gauge delivers precise battery insight without compromising battery life, design simplicity, or product cost.
Nordic's differentiations
Accurate
The algorithm-based fuel gauge solution prevents surprise shutdowns by delivering reliable and accurate battery information - providing ±3% state of charge accuracy comparable to Coulomb counters for rechargeable batteries over the lifetime of the battery, with primary‑cell accuracy depending on battery chemistry
Ultra-low power
Designed for ultra‑low power operation, the fuel gauge runs only when the system is active—using just a few microamps—to deliver accurate battery information without draining energy in sleep, extending battery life and improving reliability in IOT devices.
Low cost
Running on the host MCU, the algorithm‑based fuel gauge uses real‑time voltage, current, and temperature data from the PMIC to eliminate the need for a separate fuel‑gauge chip—reducing components, simplifying design, and lowering system cost without compromising accuracy or user experience.
Rechargeable batteries
The fuel gauge solution supports Lithium ion, Lithium polymer, and Lithium Iron Phosphate (LiFePO₄) batteries. If you require support for a battery type not currently on this list, additional chemistries may be supported upon request. Please contact the Nordic sales team for more information.
All precision fuel gauges rely on battery profiling. Traditionally, this requires sending the battery to a PMIC vendor for characterization. Nordic simplifies this process with the nPM Power Up desktop application, enabling customers to profile their selected rechargeable battery themselves and easily integrate fuel gauging and battery health into the application - resulting in a faster, more streamlined development process.
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Technology |
Nordic Fuel Gauge |
Open circuit voltage measuring |
Coloumb counting fuel gauge IC |
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Pros |
+ High accuracy |
+ No additional energy usage |
+ Best accuracy |
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+ Ultra-low power consumption |
+ No additional cost added to your bill-of-materials |
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+ No current draw at system-off |
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+ No added cost to your bill-of-materials |
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+ Battery health support |
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+ Adapts to battery ageing and over lifetime |
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+ Adapts to cell-to-cell variation across production batches |
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+ Accurate across the full operating temperature range |
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Cons |
- Needs to be supported by PMIC |
- Very low accuracy |
- Draws current even at system-off to keep coloumb counter running |
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- Severly affected by temperature |
- Expensive, adds components to your bill-of-materials (BoM) |
For selected lithium ion polymer batteries from Renata, Nordic is also providing turnkey battery models ready to use. Explore the list of supported batteries.
Primary cell batteries
The solution supports any combination of standard 1.5 V nominal AA or AAA alkaline batteries in 1S or 2S configurations, as well as coin cell and button cell batteries such as CR2032 and LR44. If you require support for a battery type not currently listed, additional types may be supported upon request. Please contact the Nordic sales team for more information.
Nordic has conducted extensive testing on primary cell batteries from leading brands and provides preconfigured generic battery models for each supported battery type in the nPM Power Up tool. This makes it easy to take advantage of fuel gauge functionality for primary cell applications, with minimal development effort.