Milliampere-hours to Ampere-hours Converter
Conversion:
1 Milliampere-hour (mAh) = 0.001 Ampere-hours (Ah)
1 Ampere-hour (Ah) = 1000 Milliampere-hours (mAh)
Conversion Formula:
Q(Ah) = Q(mAh) / 1000
Example:
Convert 3 milliampere-hours to ampere-hours:
Q(Ah) = 3mAh / 1000 = 0.003Ah
Conversion Result:
3 milliampere-hours is equal to 0.003 ampere-hours.
Milliampere-hours to Ampere-hours Converter
Learn how to convert between mAh and Ah, understand battery capacity, and make informed decisions about your electronic devices
Understanding battery capacity is crucial for anyone working with electronic devices, from smartphones to electric vehicles. The conversion between milliampere-hours (mAh) and ampere-hours (Ah) is a fundamental calculation in electrical engineering and consumer electronics.
In this comprehensive guide, we'll explore how to convert between these units, understand what they mean for your devices, and use our calculator to make quick and accurate conversions.
Why mAh to Ah Conversion Matters
What are Milliampere-hours and Ampere-hours?
Milliampere-hour (mAh) and Ampere-hour (Ah) are units of electric charge commonly used to describe battery capacity. They indicate how much current a battery can deliver over a specific period of time.
Understanding these units helps with:
- Comparing battery capacities: Evaluate different batteries for your devices
- Estimating runtime: Calculate how long a device will last on a single charge
- Designing power systems: Plan battery banks for solar systems or electric vehicles
- Troubleshooting power issues: Identify if a battery is suitable for a specific application
mAh to Ah Conversion Calculator
Milliampere-hours to Ampere-hours Converter
Conversion Formula:
Q(Ah) = Q(mAh) / 1000
Example: 3000 mAh = 3000 / 1000 = 3 Ah
Key Concepts in Battery Capacity
Milliampere-hour (mAh)
Represents 1/1000th of an ampere-hour. Commonly used for smaller batteries in consumer electronics like smartphones, tablets, and power banks.
Ampere-hour (Ah)
Standard unit for larger battery systems. Used for car batteries, solar power systems, and electric vehicle batteries.
Relationship to Watt-hours
To calculate energy capacity in watt-hours (Wh), multiply Ah by voltage: Wh = Ah × V. This gives a better picture of total energy storage.
Practical Conversion Examples
| Milliampere-hours (mAh) | Calculation | Ampere-hours (Ah) | Common Application |
|---|---|---|---|
| 500 mAh | 500 ÷ 1000 | 0.5 Ah | Small Bluetooth headphones |
| 2,000 mAh | 2,000 ÷ 1000 | 2.0 Ah | Standard power bank |
| 4,000 mAh | 4,000 ÷ 1000 | 4.0 Ah | Smartphone battery |
| 10,000 mAh | 10,000 ÷ 1000 | 10.0 Ah | Large power bank |
| 20,000 mAh | 20,000 ÷ 1000 | 20.0 Ah | High-capacity portable power |
Quick Conversion Tip
To quickly convert mAh to Ah in your head, simply move the decimal point three places to the left. For example, 4500 mAh becomes 4.5 Ah.
Real-World Applications
1. Power Bank Capacity
Power banks are typically rated in mAh, but understanding their capacity in Ah helps compare them with other battery systems:
- A 20,000 mAh power bank = 20 Ah
- This can charge a 3,000 mAh smartphone approximately 6-7 times (accounting for efficiency losses)
- Higher capacity power banks (30,000+ mAh) are often used for camping or emergency power
2. Electric Vehicles
Electric vehicle batteries are typically rated in kWh (kilowatt-hours), but Ah ratings are also important for understanding current delivery:
- A 60 kWh EV battery with a 400V system: 60,000 Wh ÷ 400V = 150 Ah
- This helps engineers design appropriate charging systems and understand battery performance
3. Solar Power Systems
Off-grid solar systems use deep-cycle batteries rated in Ah:
- A 200 Ah deep-cycle battery = 200,000 mAh
- Multiple batteries can be connected in series or parallel to increase voltage or capacity
- Understanding Ah helps calculate how long the system can power devices during cloudy days
Important Considerations
When working with battery capacities, keep these factors in mind:
- Efficiency losses: Actual usable capacity is often less than rated capacity due to conversion losses
- Temperature effects: Battery capacity decreases in cold temperatures
- Age degradation: Batteries lose capacity over time and charge cycles
- Peukert's effect: Higher discharge rates reduce effective capacity
Advanced Battery Concepts
Energy Density vs. Power Density
While mAh and Ah measure charge capacity, they don't tell the whole story about battery performance:
- Energy density: How much energy a battery can store relative to its size (Wh/L)
- Power density: How quickly a battery can deliver energy (W/kg)
- Different battery chemistries (Li-ion, NiMH, Lead-acid) have different characteristics
C-Rate
The C-rate indicates how quickly a battery can be charged or discharged relative to its capacity:
- 1C means the battery can be fully discharged in 1 hour
- A 2 Ah battery discharged at 1C would provide 2A for 1 hour
- Higher C-rates are important for applications requiring high power, like power tools
Comparing Different Battery Types
When comparing batteries, consider both capacity (mAh/Ah) and voltage. A 3.7V 3000mAh battery stores less total energy than a 12V 10Ah battery, even though the latter has lower mAh rating: 3.7V × 3Ah = 11.1Wh vs 12V × 10Ah = 120Wh.
Frequently Asked Questions
How do I convert Ah to mAh?
To convert ampere-hours to milliampere-hours, multiply by 1000. For example, 2.5 Ah = 2.5 × 1000 = 2500 mAh.
Why are smartphone batteries rated in mAh instead of Ah?
Smartphone batteries have capacities in the thousands of milliampere-hours, so using mAh avoids decimal points and makes comparisons easier (3000 mAh vs 4000 mAh is clearer than 3 Ah vs 4 Ah).
Can I directly compare mAh ratings between batteries with different voltages?
No, mAh ratings only make sense when comparing batteries with the same voltage. For different voltages, calculate watt-hours (Wh = V × Ah) for a true comparison of energy capacity.
How does battery capacity relate to device runtime?
Runtime = Battery Capacity (Ah) / Device Current Draw (A). For example, a 2 Ah battery powering a device that draws 0.5A will last approximately 4 hours.
What's the difference between capacity and state of charge?
Capacity is the maximum charge a battery can hold (e.g., 3000 mAh). State of charge is how much charge is currently in the battery (e.g., 1500 mAh remaining, or 50%).