How to Convert Wh to mAh: Formula and CalculatorWh (Watt-hour) and mAh (milliampere-hour) are battery metrics indicating energy capacity and charge capacity, respectively. Wh = Voltage (V) × mAh ÷ 1000. For instance, a 10Wh battery at 3.7V holds ~2700mAh. These values help users assess runtime (Wh) and current delivery duration (mAh), critical for sizing batteries in devices like smartphones or power banks.
How do Wh and mAh differ in assessing battery performance?
Wh measures total energy storage, factoring in voltage, while mAh quantifies charge volume at a specific voltage. For example, a 20Wh battery could be 5V × 4000mAh or 10V × 2000mAh. Pro Tip: Use Wh for solar systems requiring energy density, mAh for low-voltage gadgets needing charge cycles.
Wh provides a voltage-agnostic energy snapshot, making it ideal for comparing batteries across different voltages. In contrast, mAh is voltage-dependent—two 3000mAh batteries at 3.7V and 12V store vastly different energy (11.1Wh vs. 36Wh). Transitional phrase: In practical terms, smartphones prioritize mAh (e.g., 5000mAh) because they operate at fixed voltages (3.8–4.4V). But what happens if you ignore voltage? A 10,000mAh power bank at 3.7V (37Wh) can’t match a 20,000mAh laptop battery at 11.1V (222Wh).
| Metric | Focus | Use Case |
|---|---|---|
| Wh | Total energy | EVs, solar storage |
| mAh | Charge capacity | Phones, tablets |
How do you convert mAh to Wh?
Multiply mAh by voltage (V) and divide by 1,000: Wh = (mAh × V) ÷ 1000. A 3000mAh battery at 3.7V equals 11.1Wh. Pro Tip: Check device voltage ratings first—miscalculations lead to under/overestimating runtime.
Imagine you’re sizing a drone battery: a 6,000mAh pack at 22.2V (6S LiPo) delivers 133.3Wh, enabling 25-minute flights. But if you only consider mAh, a 10,000mAh power bank at 3.7V (37Wh) might seem superior—it’s not. Transitional phrase: To put this in perspective, energy (Wh) determines how long a device runs, while mAh reveals how much charge flows hourly. Need to power a 60W device? A 100Wh battery lasts 1.66 hours regardless of mAh.
| mAh | Voltage | Wh |
|---|---|---|
| 5000 | 3.7V | 18.5 |
| 2000 | 12V | 24 |
Why do battery specs list both Wh and mAh?
How to Convert Ah to kWh: Formula and CalculatorManufacturers use both metrics to cater to different user needs: mAh simplifies comparisons for single-voltage devices (e.g., phones), while Wh standardizes energy across multi-cell systems (e.g., EVs). Pro Tip: Engineers favor Wh for UPS backups where voltage varies, but consumers prefer mAh for portable chargers.
Consider electric bikes: a 48V 20Ah battery (960Wh) offers a 50-mile range, whereas a 12V 80Ah battery (960Wh) is bulky and impractical. Transitional phrase: Here’s the catch—Wh matters for energy-intensive tasks like uphill cycling, whereas mAh is irrelevant without voltage context. Ever wondered why power tool batteries list both? A 20V 5Ah (100Wh) battery drives drills longer than a 12V 8Ah (96Wh) unit despite lower mAh.
How do voltage fluctuations impact Wh/mAh calculations?
Actual voltage during discharge affects accuracy. Lithium-ion cells drop from 4.2V to 3.0V, so manufacturers use nominal voltage (3.7V) for calculations. Pro Tip: Use a multimeter to measure real-time voltage for precise Wh estimates.
A smartphone battery rated at 3.85V (nominal) might peak at 4.4V. If you calculate Wh at peak voltage, a 4000mAh battery appears as 17.6Wh, but actual average is ~15.4Wh. Transitional phrase: Think of it like a car’s MPG—highway vs. city mileage. For drones, voltage sag during flight reduces effective Wh, shortening hover time unexpectedly.
Redway Battery Expert Insight
FAQs
No—without considering voltage, higher mAh doesn’t mean more energy. A 5000mAh at 3.7V (18.5Wh) stores less than 2000mAh at 12V (24Wh).
How do I calculate Wh from mAh?
Multiply mAh by voltage (V) and divide by 1000. Example: 3000mAh × 5V = 15Wh.
Why do EVs use Wh instead of mAh?
Wh standardizes energy across varying voltages—critical for comparing range (e.g., 60kWh vs. 100kWh packs).
Which matters more for a power bank: mAh or Wh?
Check both: mAh indicates charge capacity, but Wh (e.g., 37Wh) determines if it complies with airline limits.
