How Battery Voltage, Capacity, and Energy Affect E-Bike Performance

A Simple and Clear Guide for Buyers and B2B Customers

When buyers choose an electric bike battery, they usually ask three questions:
“How far can it go?” “Is the power strong enough?” “Is a bigger battery always better?”

To answer these questions, we need to understand three core battery parameters:

• Voltage (V)

• Capacity (Ah)

• Energy (Wh)

 01. Voltage (V) — The Key Factor That Determines Power

Voltage represents the “force” that drives the motor.
Higher voltage = stronger power.

Why does higher voltage give stronger performance?

Because it allows the motor to draw more power, resulting in:

• Faster acceleration

• Better hill-climbing ability

• Higher top speed

• More responsive riding experience

Common voltage levels and their features

Important: The motor and controller must match the battery voltage, or the bike will not work properly.

 02. Capacity (Ah) — The Main Factor That Determines Range

Capacity (amp-hours) tells you how much charge the battery can store.

Higher Ah = longer riding distance

• 10Ah → Short city rides

• 13Ah → Standard commuting

• 15–20Ah → Long-range riding

• 20Ah+ → Delivery, cargo, or touring bikes

Example:

• A 48V 10Ah battery → approx. 35–45 km

• A 48V 15Ah battery → approx. 50–70 km

Actual range also depends on terrain, temperature, speed mode, and rider weight.

 03. Wh (Watt-hours) — The Most Accurate Indicator of True Range

Many sellers only list Ah, but Wh is the real measurement of total energy.

Formula:

Wh = Voltage × Capacity

Example

• 48V 15Ah → 720Wh

• 48V 20Ah → 960Wh

A higher Wh battery always provides longer range.

 04. How the Parameters Work Together

Voltage (V) affects:

✔ Power
✔ Acceleration
✔ Climbing ability
✔ Top speed

Capacity (Ah) affects:

✔ How far you can ride on one charge

Wh affects:

✔ Total available energy
✔ Real-world riding distance

 05. Example Comparison: Which Battery Has Longer Range?

Buyer question:
“Which lasts longer: 48V 20Ah or 52V 15Ah?”

Calculate Wh:

• 48V × 20Ah = 960Wh

• 52V × 15Ah = 780Wh

✔ 48V 20Ah has longer range
✔ 52V 15Ah has stronger power

So your recommendation should depend on what the customer wants:

• For range → choose higher Wh

• For power → choose higher voltage

 06. How to Recommend the Right Battery to Your Customers

① Daily city commute

48V 13Ah / 48V 15Ah

② Hilly cities

52V 15Ah

③ Long-distance riders

48V 20Ah / 52V 20Ah

④ Commercial & delivery use

48V 20–25Ah or 60V systems

⑤ Budget buyers

48V 12Ah or 48V 13Ah (best price/performance)

 07. Quick Summary: How to Judge a Good E-Bike Battery

Just look at these three values:

✔ Voltage — determines power

✔ Capacity — determines range

✔ Wh — the true energy rating