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Battery

Battery C-Rate Calculator

Find discharge C-rate and runtime from capacity and load current—updates live.

Battery capacityAh

Discharge currentA

Discharge C-rate

Enter Ah and discharge amps

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About Battery C-Rate Calculator

C-rate formula

C-rate = discharge current ÷ capacity (A ÷ Ah). 1C on a 100 Ah pack = 100 A and ~1 hour to empty. 0.5C = 50 A and ~2 hours.

Why C-rate matters

High C-rates heat cells and reduce effective capacity. Check your battery datasheet for max continuous discharge.

Frequently asked questions

Q: Is this linear? A: Real packs sag under load—this is an ideal estimate. Q: What about Peukert? A: Lead-acid loses more capacity at high C; lithium is closer to linear for planning.

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