Estimating battery-state of non-rechargeable applications
Applications using non-rechargeable batteries, rarely have an indication of the remaining energy or operation time of the device. Instead manufacturers rely on the availability of replacement batteries, and the end-users ability to change the battery once the device dies. In certain situations, and for certain applications, it can be useful, not to say essential, for the end-user to know what the state-of-charge of their non-rechargeable device is.
Having this information available to the end-user could mitigate the temptation to preemptively change an only partially discharged battery, to ensure guaranteed operation of the device for a period of time. Giving the end-user the ability to confirm that the battery is, in fact, only partially discharged, creates an impression of a longer battery life. In turn this leads to a more satisfied customer and better reputation for the products battery life and it also lowers the products environmental impact by reducing battery waste.
The reason battery fuel gauging is not implemented in primary-cell powered applications are many, but mostly it is due to fact that the mainstream methods avaiable for estimating this gives inaccurate and unreliable results. That is why we, in the nPM2100 PMIC, implemented the same type of algorithm-based, highly accurate fuel gauge found in the nPM1300 PMIC, but for non-rechargeable batteries. The algorithms work with any combination of standard 1.5 V nominal AA or AAA alkaline batteries, 1S or 2S, as well as coin-cell and button-cell batteries, like CR2032 and LR44. More battery types will be supported based on reported customer needs.