I am currently developing a humidity sensor-based wireless sensor node powered by a primary battery, either lithium thionyl chloride (LiSOCl₂) or lithium manganese dioxide (LiMnO₂). The objective is to operate the sensor for 5 to 10 years without battery replacement. To monitor the remaining battery life, I plan to integrate a fuel gauge IC. The sensor will be active for 20 µs, during which it will take humidity measurements, and will remain in sleep mode for the rest of the cycle. The measurement interval can be 5 minutes, 10 minutes, or 15 minutes.

Currently, the active current of the sensor module is 20 mA, and the sleep current is 60 µA.

My requirements are:

1. Very low active and sleep current.
2. Should be able to go in sleep mode during the sleep time of the sensor without affecting the accuracy.

Can anybody suggest me the Fuel Gauge IC which meets my requirements.

Thankyou

 

My guess is that cell voltage is as good an indication of capacity as anything else. Maybe you'd want an independently-powered fuel gauge IC monitoring a prototype, but it seems unnecessary otherwise.

 

With that number of years of desired battery lifetime, it is probable that any active condition monitoring circuit will use a fair portion of the charge from the battery. Consider also how you would receive the notification of battery failure arriving.
What is the sensor supposed to do when it senses humidity???
My suggestion is to instead use one of the very long lifetime batteries presently available. NOTE!!! You will not find such products at amazon or ebay.

 

I am currently developing a humidity sensor-based wireless sensor node powered by a lithium thionyl chloride (LiSOCl₂) battery. The goal is to operate the sensor for 5 to 10 years without replacing the battery. To monitor the remaining battery life, I plan to integrate a fuel gauge IC.

The sensor is active for 20 ms during each measurement cycle and remains in sleep mode for the rest of the time. The measurement interval can be 5, 10, or 15 minutes. The active current of the sensor module is 20 mA, and the sleep current is 60 µA.

In each transmission, I would like to send both the humidity reading and the remaining battery level in percentage.



I have the following questions:

1. Will I be able to monitor the remaining battery life in percentage or State of Charge (SOC)?
2. Can the fuel gauge IC enter sleep mode during the sensor’s sleep period without compromising accuracy?
3. I require very low active and sleep current from the fuel gauge.

Is the LTC3337 suitable for this application? If not, could anybody recommend me a more appropriate fuel gauge IC that meets these requirements?

Thank you.

 

Your current consumption is too high.
There are microcontrollers that run on 10 μA and consume less than 1 μA in stop mode.