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سجل التغييرات الكاملالمحرّك 1.18.3

Battery Runtime & Sizing

Power & Regulators

Runtime of a duty-cycled load, with capacity derated for cut-off and temperature, and self-discharge counted as drain.

هذه الصفحة غير مترجمة بالكامل بعد. الأجزاء غير المترجمة معروضة بالإنجليزية.

المدخلات

mAh
V
Li-ion to 3.0 V ≈ 90–95 %; alkaline to 1.0 V ≈ 80 %; coin cell under pulse load can be 50 %
%
100 % at +20 °C, ≈ 80 % at 0 °C, ≈ 60 % at −20 °C for Li-ion
%
A
25 mA
s
A
6 µA
s
%/month
%

النتائج

Runtime

بلا حكم: the runtime you need is a product requirement. This figure is only as good as the usable fraction, derating and sleep current entered.
241.2days
Average load current Iavg
214.3µA
Usable capacity

6.29 Wh of 2000 mAh rated
1700mAh
كل النتائج (3)
Duty cycle
0.833%
Drawn from cell (with η)

incl. 55.56 µA self-discharge
293.6µA
Energy per cycle

one wake + sleep interval
47.57mJ

Active share of the drain: 97 %; sleep share: 3 %. Reduce the larger one first.

C-rate at the active current: 0.01 C. Rated capacity is usually quoted at 0.2 C; higher rates give less.

إلى أي حد نعرف هذا الرقم

يُقاس مقابل

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هذه أداة مساعدة للتصميم. يبقى المهندس مسؤولاً عن التصميم وعن قراءة المرجع القياسي نفسه حيث يهم ذلك.

المسح البارامتري

غيّر مدخلاً واحداً على مدى، وشاهد الإجابة والحكم والهامش عند كل خطوة، جدولاً ومنحنى.Pro

أسوأ الحالات

أضف التفاوتات إلى المدخلات لتحصل على النطاق المضمون حول الإجابة الاسمية، لا الحالة النموذجية وحدها.Pro

Waveform

المبدأ

Runtime is usable charge divided by average current. The hard part is the usable charge: the rated mAh is measured under laboratory conditions your product will not see.

Duty-cycled average current
Iavg=Iact D+Isleep(1−D),D=tactTcycleI_{avg} = I_{act}\,D + I_{sleep}(1-D), \qquad D = \frac{t_{act}}{T_{cycle}}
Runtime
t=CusableIavg/η+Isdt = \frac{C_{usable}}{I_{avg}/\eta + I_{sd}}
Usable capacity
Cusable=Crated⋅kcutoff⋅ktempC_{usable} = C_{rated} \cdot k_{cutoff} \cdot k_{temp}
Energy
E=CAh Vnom[Wh]E = C_{Ah}\, V_{nom} \quad \t{[Wh]}
C-rate
C-rate=ICAhC\t{-rate} = \frac{I}{C_{Ah}}
1 C discharges the rated capacity in one hour.
  • CratedC_{rated}label capacity, measured at 0.2 C and +20 °C
  • kcutoffk_{cutoff}fraction still available above your system's minimum voltage
  • ktempk_{temp}temperature derating factor
  • IsdI_{sd}self-discharge expressed as an equivalent constant current
  • η\etaefficiency of the regulator between cell and load
تفاصيل إضافية

Where runtime is lost

  • Cut-off voltage. The system stops at its brown-out threshold, not the cell's rated end voltage. A boost converter that runs down to 0.9 V gets far more from an alkaline cell than a 1.8 V LDO does.
  • Pulse current on coin cells. A CR2032 has 10–20 Ω of internal resistance, rising as it discharges. A 15 mA burst drops the terminal voltage by 200–300 mV.
  • Temperature. Li-ion loses about 20 % at 0 °C and 40 % at −20 °C. Charging below 0 °C damages the cell.
  • Ageing. Design to end-of-life capacity, typically 80 % after the rated cycle count.
  • Small leakages. Protection FET, fuel gauge, pull-ups and the battery-monitor divider all count on a microamp budget.
Measure. Record a full wake-sleep cycle with a wide-range current probe or a source-measure unit. Where it disagrees with this estimate, trust the measurement.
Related: System Power Budget for the load side; LDO Dissipation & Limits for the quiescent term.

إصدار المحرك ⁨1.18.3⁩