I want to use a fuel gauge IC for charge monitoring a primary battery (either lithium manganese dioxide or lithium thionyl chloride) in my wireless sensor node project. The goal is to power the sensor using a primary battery for 10 years without replacement.

I would like to ask whether the following fuel gauge ICs, which are primarily designed for Li-ion cells, are suitable for monitoring primary battery charge:

1. LTC2941 / LTC2942
2. MAX17201 / MAX17205 / MAX17215

I am aware that TI’s BQ35100 and Analog Devices’ LTC3337 are specifically designed for primary batteries. However, I’m interested in exploring the LTC2941/LTC2942 due to their smaller size.




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This is the image that i found on the digikey website. As it can seen a coin cell (primary) battery is connected to the LTC2942.

Thanks

 

The LTC2941 quiescent current is approximately 100uA so you would need a battery capacity of 8,760mAh just to keep it alive for 10 years.

 

There is always a compromise in engineering decisions. If you connect an active device to monitor the state of a battery charge, it will consume a part of that charge to operate. That is explained in post #2. The bad news is that the conclusion given is correct. There may be other devices that draw less current.