In an electric bicycle, the motor, controller, and battery form a tightly connected power system.
If any of these three components are not properly matched, the e-bike may suffer from:
Weak acceleration
Voltage cutoff during riding
Overheating motors
Battery damage
Shortened lifespan
Even complete system failure
This guide explains how these components work together and how to ensure the perfect match, especially for B2B buyers or customers choosing customized battery packs.
A battery determines how much energy the system can deliver.
Its key parameters:
Common levels:
36V – city/commuter bikes
48V – mainstream power system
52V – higher torque and acceleration
60V – high-power cargo/off-road systems
The battery voltage MUST match the controller and motor.
Higher Ah = longer riding range.
(Does NOT increase torque or power.)
This is commonly ignored but extremely important.
Battery discharge current must ≥ controller current.
If not, the battery may:
Cut off during acceleration
Overheat
Trigger BMS protections
Lose capacity faster
The controller regulates how much current goes to the motor.
Its specifications determine the e-bike’s real output power.
Key parameters:
Must be the same as the battery.
This determines torque and acceleration.
Formula:
Power (W) = Voltage (V) × Current (A)
Example:
48V × 18A ≈ 860W
48V × 25A ≈ 1200W
Higher current = stronger torque.
Over-current protection
Short-circuit protection
Temperature protection
A good controller improves both performance and safety.
Motor matching focuses on whether it can handle the controller’s output.
Key parameters:
Typical: 250W / 350W / 500W / 750W / 1000W
Usually 2–2.5× the rated power.
For example:
A 750W motor may reach 1200–1500W peak.
Again, must match battery & controller.
Determines torque vs. speed characteristics.
These are the simplest and most reliable matching rules used by most OEM factories:
✔ 48V battery → 48V controller → 48V motor
✘ 36V battery + 48V controller (bike won’t start)
✘ 48V battery + 36V motor (risk of burning the motor)
Example:
Controller: 48V 25A
Battery must support at least 25A continuous.
Otherwise:
Sudden cutoff
Poor acceleration
Battery overheating
BMS shutdown
Example:
750W motor → peak ~25–28A
So the proper controller is:
✔ 48V 22–25A
✘ 48V 30A (may overheat the motor)
| Battery | Controller | Motor | Application |
|---|---|---|---|
| 36V 10Ah | 15A | 250W | City commuting |
| 48V 13Ah | 18A | 350–500W | Daily commuting / light trails |
| 48V 15–17Ah | 22A | 750W | High-torque bikes |
| 52V 17–20Ah | 25–28A | 750–1000W | Off-road eBike |
| 60V 20Ah+ | ≥35A | 1200W+ | Cargo / Extreme off-road |
These combinations ensure stable performance and component longevity.
When buying in bulk, ask your supplier for:
Full motor–controller–battery matching proposal
BMS rated current
Load test report
Discharge curve
Wiring diagram
This prevents compatibility failures and reduces after-sales issues.
→ Controller current too high but battery current too low.
→ BMS over-current protection.
→ Controller delivers more current than the motor can handle.
→ Voltage mismatch.
→ Long-term over-current discharge.
Battery = fuel tank
Controller = throttle & brain
Motor = engineAll three must match in voltage and current levels to ensure stable power, long lifespan, and maximum performance.
In an electric bicycle, the motor, controller, and battery form a tightly connected power system.
If any of these three components are not properly matched, the e-bike may suffer from:
Weak acceleration
Voltage cutoff during riding
Overheating motors
Battery damage
Shortened lifespan
Even complete system failure
This guide explains how these components work together and how to ensure the perfect match, especially for B2B buyers or customers choosing customized battery packs.
A battery determines how much energy the system can deliver.
Its key parameters:
Common levels:
36V – city/commuter bikes
48V – mainstream power system
52V – higher torque and acceleration
60V – high-power cargo/off-road systems
The battery voltage MUST match the controller and motor.
Higher Ah = longer riding range.
(Does NOT increase torque or power.)
This is commonly ignored but extremely important.
Battery discharge current must ≥ controller current.
If not, the battery may:
Cut off during acceleration
Overheat
Trigger BMS protections
Lose capacity faster
The controller regulates how much current goes to the motor.
Its specifications determine the e-bike’s real output power.
Key parameters:
Must be the same as the battery.
This determines torque and acceleration.
Formula:
Power (W) = Voltage (V) × Current (A)
Example:
48V × 18A ≈ 860W
48V × 25A ≈ 1200W
Higher current = stronger torque.
Over-current protection
Short-circuit protection
Temperature protection
A good controller improves both performance and safety.
Motor matching focuses on whether it can handle the controller’s output.
Key parameters:
Typical: 250W / 350W / 500W / 750W / 1000W
Usually 2–2.5× the rated power.
For example:
A 750W motor may reach 1200–1500W peak.
Again, must match battery & controller.
Determines torque vs. speed characteristics.
These are the simplest and most reliable matching rules used by most OEM factories:
✔ 48V battery → 48V controller → 48V motor
✘ 36V battery + 48V controller (bike won’t start)
✘ 48V battery + 36V motor (risk of burning the motor)
Example:
Controller: 48V 25A
Battery must support at least 25A continuous.
Otherwise:
Sudden cutoff
Poor acceleration
Battery overheating
BMS shutdown
Example:
750W motor → peak ~25–28A
So the proper controller is:
✔ 48V 22–25A
✘ 48V 30A (may overheat the motor)
| Battery | Controller | Motor | Application |
|---|---|---|---|
| 36V 10Ah | 15A | 250W | City commuting |
| 48V 13Ah | 18A | 350–500W | Daily commuting / light trails |
| 48V 15–17Ah | 22A | 750W | High-torque bikes |
| 52V 17–20Ah | 25–28A | 750–1000W | Off-road eBike |
| 60V 20Ah+ | ≥35A | 1200W+ | Cargo / Extreme off-road |
These combinations ensure stable performance and component longevity.
When buying in bulk, ask your supplier for:
Full motor–controller–battery matching proposal
BMS rated current
Load test report
Discharge curve
Wiring diagram
This prevents compatibility failures and reduces after-sales issues.
→ Controller current too high but battery current too low.
→ BMS over-current protection.
→ Controller delivers more current than the motor can handle.
→ Voltage mismatch.
→ Long-term over-current discharge.
Battery = fuel tank
Controller = throttle & brain
Motor = engineAll three must match in voltage and current levels to ensure stable power, long lifespan, and maximum performance.