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Capacity/current estimate with an adjustable factor (default 0.7). Temperature, age and discharge rate affect runtime.
t (h) = Q (Ah) / I (A) × k; k = 0.7
Estimate battery runtime from capacity, load current and an adjustable 0.7 factor. Learn duty-cycle averaging, mAh versus Wh and model limits.
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Use t(h) = capacity(Ah) × factor / current(A). Estimate battery runtime from capacity, load current and an adjustable 0.7 factor. Learn duty-cycle averaging, mAh versus Wh and model limits.
Sources: forum.digikey.com [1]
14 h; factor = 1 → 20 h. This is a calculated example under the model stated above; it is not a measured component specification.
mAh or Ah; mA or A; h. Convert prefixes before substituting values; keep the input and output units attached to every number.
Sources: forum.digikey.com [1]
No. It is an adjustable allowance, not a universal battery law. Use discharge curves and cutoff voltage for a specific cell and load.
Sources: forum.digikey.com [1]
Use time-weighted battery-side current: Iavg = Σ(Iᵢtᵢ)/Σtᵢ. Include regulator loss, quiescent current and wake-up pulses.
Voltage is also required: Wh ≈ Ah × average voltage. A converter’s output current is not necessarily the battery current.
Sources: nist.gov [1]
Answers use the stated model and units. Examples are calculated values, not measurements or component ratings.
