Analog Devices has released the LTC3337, a nanopower primary (non-rechargeable) cell State-of-Health (SoH) monitor with precision coulomb counter, intended to be placed in series with a primary battery with minimal associated series voltage drop. The patented infinite dynamic range coulomb counter counts all accumulated battery discharge and stores it in an internal register obtainable through an I2C interface. Quiescent current consumption is only 100nA, increasing battery run time.
The device combines additional SoH variable monitoring, which measures and reports through I2C: battery voltage, battery impedance, and temperature. To accommodate a broad range of primary battery inputs, the peak input current limit is pin selectable from 5mA to 100mA. This allows the IC to present the battery with a load profile which enables it to produce its maximum capacity, independent of the actual load. This is ‘battery-friendly’ and prolongs the lifetime of the cell. It is ideal for primary cell applications that need only occasional power, such as applications in remote locations, electronic door locks, or glass break detectors. The device can also be employed in rechargeable battery cell applications.