Coulombs to Ah Converter
Professional Battery Capacity Converter | C ↔ Ah with Exact 3,600 Second Factor
🔋 Battery Capacity Reference Table
| Ampere-Hours (Ah) | Coulombs (C) | Common Battery Example |
|---|---|---|
| 0.1 | 360 | Small coin cell |
| 1 | 3,600 | AA rechargeable |
| 2 | 7,200 | Smartphone battery |
| 5 | 18,000 | Laptop battery |
| 10 | 36,000 | Car starter battery |
| 50 | 180,000 | EV battery module |
| 100 | 360,000 | Industrial UPS |
🔋 Understanding Coulombs and Ampere-Hours
The Fundamental Relationship
Charge Q, current I, and time t are related by \( Q = I \times t \). An ampere-hour represents 1 ampere flowing for 1 hour: \( 1\ \text{Ah} = 1\ \text{A} \times 3{,}600\ \text{s} = 3{,}600\ \text{C} \).
The conversion factor 3,600 is exact. It comes from 60 minutes × 60 seconds = 3,600 seconds per hour, making Ah ↔ C conversions precise without approximation.
Battery Capacity Applications
Battery datasheets list capacity in Ah because it's practical for end users. A 2 Ah smartphone battery delivers 2 amps for 1 hour, or 1 amp for 2 hours, or any equivalent combination totaling 7,200 coulombs of charge.
Electrical engineers often need both units. Coulombs for fundamental calculations (Q = CV, Q = It), ampere-hours for battery specifications and runtime estimates.
Practical Conversion Examples
AA rechargeable: 2,000 mAh = 2 Ah = 7,200 C. Smartphone: 4,000 mAh = 4 Ah = 14,400 C. Car battery: 50 Ah = 180,000 C. These match manufacturer specifications exactly.
❓ Battery Capacity FAQs
1 Ah = 1 A × 1 hour = 1 A × 3,600 s = 3,600 C. The number 3,600 is exact: 60 minutes/hour × 60 seconds/minute = 3,600 seconds/hour, and Q = I × t gives the direct relationship.
1 mAh = 0.001 Ah = 3.6 C. So mAh × 3.6 = coulombs. Example: 2,500 mAh smartphone battery = 2.5 Ah = 9,000 C total capacity.
Yes, the conversion is exact regardless of battery chemistry. Li-ion, NiMH, lead-acid—all store charge as coulombs. Ah ratings assume full discharge at rated current, but the C ↔ Ah math is always precise.
