Battery Life Calculator
Estimate how long a battery will last given its capacity, voltage, load power and inverter/conversion efficiency.
How to Use the Battery Life Calculator
- Enter battery capacity in mAh.
- Enter nominal voltage.
- Enter total load power in watts.
- Enter expected conversion efficiency (default 85).
- Click Calculate to see runtime in hours.
使用例
- •Sizing portable power stations.
- •Planning camping or field-work battery reserves.
- •Drone or RC vehicle flight time estimates.
計算式
Hours = (capacity_mAh × voltage × efficiency/100) / load_W / 1000 × 1000. Simplified: hours = (mAh × V × η) / (1000 × load_W).
よくある質問
Why include efficiency?
Most batteries drive loads through a regulator or inverter that is not 100% efficient. Typical DC-DC efficiency is 85–95%; inverters for AC loads are 80–90%.
What if my capacity is in Wh?
Convert Wh to mAh with mAh = Wh × 1000 / V, or just compute hours directly as Wh × η / load_W.
Does this account for self-discharge?
No. For long-term storage, subtract 2–5% per month for lithium-ion and 10–30% per month for NiMH.