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TPS65218: How to calculate lifetime for coin cell.

Hayashi
Expert 1840 points
Part Number: TPS65218

Hi teams

My customer wants to know how to calculate lifetime for coin cell battery.

Please let me know how to calculate by the formula.

The its capacity assumed 220mAh.

Of course, they know it depends on specification and condition.

They wants to know worst case and how to calculate.

Please contact me if you have any questions

Best regard

Hayashi

  • 0
    TI__Expert 4155 points

    Hayashi,

    There isn't a specific formula for coin cell life on this device as far as I know, but the main determining factor will be how much current your DCDC5 and DCDC6 rails are pulling.

    You would want to divide your battery capacity by your current draw, and multiply that by the efficiency of the DCDC5 and DCDC6 rails.

    For example, if your rails pulled a combined 15uA, then with a 220mAh battery you would get 0.22/0.000015 = 14,666.66 hours of battery. Of course the device isn't 100% efficient, so if you assume 80% efficiency (I believe it would probably be higher, but 80% would be a safe assumption) then you would get 14,666.66*0.8 = 11,733.33 hours of battery life.

    Let me know if this is sufficient, or I can try to find an accurate number for the DCDC5 and DCDC6 efficiency.

    Thank you,

    Nick