Convert in any direction here, then check the result against the 100 Wh and 160 Wh airline thresholds that decide whether your battery can travel with you.
How do you convert amp-hours to watt-hours?
Multiply amp-hours by the battery’s nominal voltage: Wh = V × Ah. A 36 V 10 Ah pack holds 360 Wh and a 48 V 10 Ah pack 480 Wh. For milliamp-hours, divide by 1,000 first. Airlines allow spare batteries up to 100 Wh in carry-on, and up to 160 Wh with approval.
Why watt-hours and not amp-hours
Amp-hours measure charge, not energy. A 36 V 10 Ah pack and a 48 V 10 Ah pack both hold "10 Ah" but the second stores a third more energy — 480 Wh against 360 Wh — and will go a third further. Watt-hours combine voltage and charge into the number that actually predicts range.
The formulas are one multiplication each way: Wh = V × Ah, and Ah = Wh ÷ V. Milliamp-hours are just amp-hours × 1000, which is why phone and power-bank marketing prefers them: 20,000 mAh sounds better than 74 Wh. Always divide mAh by 1000 before multiplying by voltage.
Which voltage to multiply by
Use nominal voltage. A 10-series lithium-ion pack is 36 V nominal (10 × 3.6 V) even though it charges to 42 V and cuts out around 30 V. Multiplying by the 42 V charge voltage inflates capacity by 17%, which is exactly the trick some sellers use on marketplace listings.
Chemistry sets the per-cell figure: standard lithium-ion (NMC/NCA) is 3.6–3.7 V nominal, LiFePO4 is 3.2 V, and lead-acid is 2 V. So 13S lithium-ion is 48 V, while a "48 V" LiFePO4 pack is 15S or 16S. Get this wrong and your charger will not match the pack.
Typical pack sizes, for scale
Watt-hours is the only figure that compares fairly across voltages, which makes this table a useful reality check when a listing quotes amp-hours alone.
| Vehicle | Typical pack | Example configuration | Example in kWh |
|---|---|---|---|
| Entry commuter scooter | 270–300 Wh | 36 V 7.8 Ah | 0.28 |
| Mid-range scooter | 450–650 Wh | 36 V 15 Ah | 0.54 |
| Long-range scooter | 900–1200 Wh | 48 V 21 Ah | 1.01 |
| Performance scooter | 1500–3000 Wh | 60 V 35 Ah | 2.10 |
| City e-bike | 400–750 Wh | 36 V 17 Ah | 0.61 |
| Electric motorbike | 4000–9000 Wh | 72 V 90 Ah | 6.48 |
| Compact electric car | 40,000 Wh | 350 V 115 Ah | 40.3 |
Flying with a battery: 100 Wh and 160 Wh
IATA rules, which nearly every airline follows, allow spare lithium batteries up to 100 Wh in carry-on without approval. From 100 Wh to 160 Wh you need the airline's consent in advance, and you are usually limited to two. Above 160 Wh, passenger aircraft will not carry it in cabin or hold.
That puts almost every electric scooter out of bounds. A 280 Wh Xiaomi-class battery — the smallest common commuter pack — is nearly double the hard limit, which is why scooters cannot be checked as luggage and why removable-battery scooters are not a workaround. Power banks and camera batteries are the ones that fit under 100 Wh.
| Energy | Carry-on | Checked baggage | Examples |
|---|---|---|---|
| Under 100 Wh | Yes, no approval | Installed in a device only | Phones, laptops, most power banks |
| 100–160 Wh | With airline approval | Installed in a device, with approval | Cinema camera batteries, large banks |
| Over 160 Wh | No | No | Every electric scooter and e-bike pack |
How the calculator works
Whatever unit you type, the calculator converts it to watt-hours first using the nominal pack voltage, then derives every other unit from that. The range estimate assumes 90% of the pack is usable — the rest is held back by the BMS — and divides by the consumption figure you enter.
The formula
Wh → kWh ÷ 1000
Range ≈ ( Wh × 0.9 ) ÷ Wh/km // 0.9 for BMS reserve
Related calculators
Watt-hours is the number every other tool wants. Feed it into the range calculator for distance and the charging cost calculator for running cost. If you are building rather than buying, the pack calculator works backwards from a watt-hour target to a cell layout.
Questions riders actually ask
How do I convert mAh to Wh?
Divide mAh by 1000 to get amp-hours, then multiply by nominal voltage. A 20,000 mAh power bank with 3.7 V cells is 20 × 3.7 = 74 Wh — comfortably under the 100 Wh airline limit, despite the alarming-looking mAh figure.
How many watt-hours is a typical electric scooter?
Entry commuters sit at 270–300 Wh, mid-range at 450–650 Wh, long-range models at 900–1200 Wh, and performance scooters run 1500–3000 Wh. For comparison, a small electric car is around 40,000 Wh (40 kWh).
Is a higher voltage pack better than a higher amp-hour pack?
For the same watt-hours they store the same energy, but higher voltage draws less current for the same power, which means thinner wiring, cooler controllers and less voltage sag under load. That is why performance scooters moved to 60 V and 72 V rather than simply adding parallel cells.
How do I work out watt-hours from cell specs?
Multiply cells in series × nominal cell voltage × (cells in parallel × cell capacity in Ah). A 13S4P pack of 3000 mAh cells is 13 × 3.6 V × 12 Ah = 561 Wh. The battery pack calculator does this along with weight, cost and current limits.
Why does my scooter show fewer watt-hours than the label?
Labels quote nominal new capacity. Real usable energy is lower because the BMS reserves headroom at both ends (typically 8–15%) and because the pack has aged. Two years of daily commuting commonly leaves 85–90% of the original capacity.
Sources
Primary and reference sources for the physics, standards and figures used on this page.
- Lithium batteriesIATA
- PackSafe: Lithium batteriesFederal Aviation Administration