Battery Specifications
80%
90%
Load Characteristics
100%
Continuous
Estimated Runtime
Total Runtime
18.0 hours
(18.0 hours)
Usable Capacity
1800 mAh
(80% DOD)
Average Draw
100.0 mA
(100% duty)
Days
0.8
C-Rate
0.04C
Calculation Steps
1. Battery capacity: 2500 mAh
2. Load current: 100.0 mA
3. Depth of discharge: 80%
4. Step 1: Usable capacity = 2500 mAh × 0.8 = 2000.0 mAh
5. Step 2: Effective capacity (90% efficiency) = 2000.0 × 0.9 = 1800.0 mAh
6. Step 4: Runtime = 1800.0 mAh ÷ 100.0 mA = 18.00 hours
7. C-Rate: 100 mA / 2500 mAh = 0.040C
Battery Life Concepts
Depth of Discharge (DOD):
- • Li-ion: 80-90% safe DOD
- • Lead Acid: 50% max for longevity
- • NiMH: 80-85% typical
- • Alkaline: 80% usable
C-Rate:
- • C/20 (0.05C): Very light load
- • C/10 (0.1C): Light load
- • C/5 (0.2C): Moderate
- • 1C: Heavy (1hr discharge)
- • >2C: Very heavy
Runtime Formula:
Runtime = (Capacity × DOD × η) / (Current × Duty)