Wondering how many hours your e-bike battery will last before it runs flat? Use the instant interactive calculator below or look up your exact battery specifications (36V, 48V, or 52V) in our verified runtime tables.
⚡ Interactive E-Bike Battery Runtime Calculator
Instant Readout
The Formula: How E-Bike Battery Runtime Is Calculated
Calculating battery runtime comes down to basic electrical physics. Every battery stores energy measured in Watt-Hours (Wh):
Runtime in Hours = Battery Capacity (Wh) ÷ Average Motor Draw (Watts)
For example, a common UK setup with a 48V 13Ah battery and a 250W road-legal motor:
- Total Energy:
48V × 13Ah = 624 Watt-Hours (Wh) - Full Power Continuous Runtime:
624Wh ÷ 250W = 2.49 hours (approx 2 hours 30 minutes)
In real-world riding, you do not pull 250W continuously. When pedalling on flat tarmac in standard assist, a 250W motor draws an average of 100 to 140 watts, stretching real runtime to 4 to 5 hours.
If you want to estimate your total mileage per charge instead of time, use our companion guide to calculate the range of your electric bike battery.
36V E-Bike Battery Runtime Table
36-volt batteries are standard on urban commuter bikes, folding e-bikes, and hybrid road bikes with 250W motors:
| Battery (V & Ah) | Capacity (Wh) | Run Time at 250W Full Power | Standard Assist Runtime (PAS 2-3) | Estimated Range |
|---|---|---|---|---|
| 36V, 7.8Ah | 280.8 Wh | 1.12 hrs (1h 07m) | 2.2 to 2.8 hrs | 18 – 25 miles |
| 36V, 9.6Ah | 345.6 Wh | 1.38 hrs (1h 23m) | 2.6 to 3.4 hrs | 22 – 30 miles |
| 36V, 10Ah | 360.0 Wh | 1.44 hrs (1h 26m) | 2.8 to 3.6 hrs | 24 – 32 miles |
| 36V, 14Ah | 504.0 Wh | 2.02 hrs (2h 01m) | 3.8 to 5.0 hrs | 35 – 45 miles |
| 36V, 17Ah | 612.0 Wh | 2.45 hrs (2h 27m) | 4.8 to 6.2 hrs | 42 – 55 miles |
48V E-Bike Battery Runtime Table
48-volt batteries power electric mountain bikes, cargo bikes, and high-torque motors. Here is the runtime across 250W UK-legal motors up to 1000W performance motors:
| Battery (V & Ah) | Capacity (Wh) | 250W Full Power | 500W Full Power | 1000W Full Power | Real-World PAS Runtime |
|---|---|---|---|---|---|
| 48V, 10Ah | 480 Wh | 1.92 hrs (1h 55m) | 0.96 hrs (58m) | 0.48 hrs (29m) | 3.0 to 4.5 hrs |
| 48V, 13Ah | 624 Wh | 2.50 hrs (2h 30m) | 1.25 hrs (1h 15m) | 0.62 hrs (37m) | 4.0 to 5.5 hrs |
| 48V, 15Ah | 720 Wh | 2.88 hrs (2h 53m) | 1.44 hrs (1h 26m) | 0.72 hrs (43m) | 4.5 to 6.5 hrs |
| 48V, 16Ah | 768 Wh | 3.07 hrs (3h 04m) | 1.54 hrs (1h 32m) | 0.77 hrs (46m) | 5.0 to 7.0 hrs |
| 48V, 19Ah | 912 Wh | 3.65 hrs (3h 39m) | 1.82 hrs (1h 49m) | 0.91 hrs (55m) | 6.0 to 8.5 hrs |
| 48V, 20Ah | 960 Wh | 3.84 hrs (3h 50m) | 1.92 hrs (1h 55m) | 0.96 hrs (58m) | 6.5 to 9.0 hrs |
| 48V, 22Ah | 1056 Wh | 4.22 hrs (4h 13m) | 2.11 hrs (2h 07m) | 1.06 hrs (1h 03m) | 7.0 to 10.0 hrs |
52V E-Bike Battery Runtime Table
52-volt batteries deliver higher top speed and less voltage sag. They are commonly paired with 750W, 1000W, and 2000W motor kits:
| Battery (V & Ah) | Capacity (Wh) | At 1000W Full Throttle | At 2000W Extreme Draw | At 250W Pedal Assist | Estimated Range |
|---|---|---|---|---|---|
| 52V, 10Ah | 520 Wh | 0.52 hrs (31 mins) | 0.26 hrs (16 mins) | 3.5 to 4.5 hrs | 25 – 35 miles |
| 52V, 13Ah | 676 Wh | 0.68 hrs (41 mins) | 0.34 hrs (20 mins) | 4.5 to 6.0 hrs | 35 – 48 miles |
| 52V, 16Ah | 832 Wh | 0.83 hrs (50 mins) | 0.42 hrs (25 mins) | 5.5 to 7.5 hrs | 45 – 60 miles |
| 52V, 19Ah | 988 Wh | 0.99 hrs (59 mins) | 0.49 hrs (30 mins) | 6.5 to 9.0 hrs | 55 – 72 miles |
| 52V, 20Ah | 1040 Wh | 1.04 hrs (1h 02m) | 0.52 hrs (31 mins) | 7.0 to 9.5 hrs | 60 – 80 miles |
| 52V, 22Ah | 1144 Wh | 1.14 hrs (1h 08m) | 0.57 hrs (34 mins) | 7.5 to 10.5 hrs | 65 – 88 miles |
Key Factors That Drain Your E-Bike Battery Faster
1. Cold British Temperatures
Lithium-ion cells rely on liquid chemical electrolytes. When outdoor temperatures drop below 10°C (common throughout British autumn and winter), internal cell resistance rises sharply. A battery that delivers 40 miles in July can drop to 28 to 32 miles in January. Storing and charging your battery inside at room temperature preserves usable capacity.
2. Rider and Cargo Weight
Every extra kilogram demands higher continuous amperage from the motor to maintain cruising speed. A 95kg rider ascending an 8% incline draws nearly double the wattage of a 65kg rider on flat ground.
3. Tyre Pressure and Rolling Resistance
Soft tyres create heavy rolling drag. Under-inflated tyres force the motor to work continuously even on smooth asphalt, draining 15% to 25% of your available runtime. Check your tyre pressure weekly against the PSI rating printed on the sidewall.
4. Riding Cadence and Assist Modes
Cadence sensors draw power when you spin the pedals, while torque sensors scale motor power to your physical pedal effort. Riding exclusively in maximum turbo assist or leaning heavily on a thumb throttle will empty an e-bike pack in under an hour.
4 Practical Rules to Extend Every Charge
- Drop one assist level: Riding in PAS 2 or 3 instead of Turbo typically extends ride time by 30% without significant loss of average speed.
- Pedal from a standstill: Electric motors draw peak amperage (often 15A–25A) from a dead stop. Pedalling through the first two revolutions protects the battery from heavy discharge spikes.
- Maintain tyre pressure: Running tyres at manufacturer-recommended pressure reduces road friction immediately.
- Charge at room temperature: Never charge a frozen battery. Allow the pack to reach 15°C before plugging in.
For an in-depth checklist on cell balancing and storage health, read our guide on how to preserve your electric bike battery lifespan.
Is Your Battery Losing Range or Running Flat Too Fast?
Lithium-ion battery packs naturally lose capacity after 500 to 800 charge cycles. If your battery cuts out on hills or no longer gets you to work and back, you have two options:
- Add a secondary dual-battery setup: Read our guide on whether you should buy a second e-bike battery.
- Upgrade to a modern, high-capacity e-bike: Browse verified daily UK road-legal electric bike deals with factory warranties.
Frequently Asked Questions