Electric Scooter Battery Guide: Principles, Performance & Usage Recommendations

For an electric scooter, if the motor is its “muscle” and the controller is its “brain”, then the battery is undoubtedly the “heart” of the entire system. The battery not only determines whether the scooter can run fast and far, but also affects the overall lifespan and safety of the vehicle.

This educational article aims to help you understand battery working principles and key parameters in both accessible and professional terms, enabling more informed purchasing and usage decisions.

Basic Working Principles of Electric Scooter Batteries

The batteries used in electric scooters are essentially “electrochemical energy converters”. They store and release energy through reversible chemical reactions, involving the orderly flow of electrons and ions.

During discharge, oxidation-reduction reactions occur inside the battery: electrons flow from the negative electrode to the positive electrode through external circuits including the controller and motor; simultaneously, ions migrate through the electrolyte to maintain charge balance. This process converts stored chemical energy into electrical potential energy, which then drives the motor to convert it into mechanical kinetic energy, ultimately propelling the scooter forward.

Key Battery Parameters

Battery Voltage

Voltage is the “electrical pressure” that drives current flow. In batteries, it originates from chemical energy and essentially represents the potential energy difference of electrons at different positions.

Voltage directly determines the performance level of an electric scooter. According to Ohm’s law (I=V/R), with constant resistance, higher voltage means higher current and greater motor power. This is why 60V systems accelerate faster and have stronger climbing ability than 36V systems.

Battery voltage varies under different conditions. We can distinguish several concepts:

Nominal Voltage: This is the design voltage of the battery or battery pack, a theoretical rated value. For example, an 18650 lithium-ion cell typically has a nominal voltage of 3.6V or 3.7V, while an electric scooter battery pack might be 36V or 48V. This manufacturer-provided reference value may differ from actual voltage.

Open Circuit Voltage (OCV): This is the battery voltage when no load is connected (no current output). Open circuit voltage mainly depends on the State of Charge (SOC). Higher charge levels correspond to higher open circuit voltage; lower charge levels correspond to lower open circuit voltage.

Discharge Voltage (Working Voltage): This is the actual output voltage during battery discharge. When the battery outputs current, the actual output voltage is lower than the open circuit voltage due to internal resistance. Higher current results in greater voltage drop: V_discharge = V_open_circuit – I_output × R_internal_resistance

Cut-off Voltage: This is the minimum voltage allowed during battery discharge. When battery voltage drops below this value, the controller typically cuts power to prevent further discharge and protect the battery from over-discharge.

When purchasing batteries, we mainly focus on nominal voltage; actual discharge voltage is primarily used to assess battery health.

Battery Capacity (Unit: Ampere-hours, Ah)

Capacity represents the total electrical energy a battery can provide at unit voltage, directly related to range. Higher capacity means longer range. Generally, a 10Ah battery pack can support 25-30km (15-18 miles) range, while 20Ah can achieve over 60km(37 miles), though actual performance is affected by various factors.

Note that actual usable capacity is often less than the nominal value because:

• High-rate discharge reduces releasable capacity
• Low temperatures temporarily “freeze” part of the capacity
• Capacity irreversibly degrades over time
• BMS limits deep discharge for safety

When comparing different batteries, total energy (Wh = V × Ah) is a more accurate metric, avoiding misjudgments caused by voltage differences.

Discharge Rate (C)

Discharge rate determines the battery’s ability to release current per unit time. The calculation formula is: Maximum Current = C-rate × Capacity. For example, if a 20Ah battery has a 2C discharge rate, the maximum continuous discharge current is 40A.

This parameter is extremely important for electric scooters because startup acceleration and hill climbing require high current support. Insufficient battery discharge rate can cause inadequate power, voltage drop, or protection system intervention. However, high-rate discharge also increases heat generation and safety risks.

Internal Resistance

Internal resistance is the battery’s internal impedance to current flow—an often overlooked but very important parameter. Higher internal resistance causes more severe voltage drop during use and generates more heat, leading to energy loss and performance degradation.

As battery usage time increases, internal resistance gradually increases, which is an important sign of battery aging. When internal resistance increases to a certain extent, even with remaining capacity, the battery cannot provide sufficient power output.

Purchase Tip: Choose batteries with sufficient total energy (Wh) and adequate discharge rate (discharge rate ≥ controller maximum current / battery capacity) based on actual needs.

Synergistic Relationship Between Battery, Motor, and Controller

The electric scooter’s power system is a precision collaborative system. The battery, as the energy source, must have output characteristics that perfectly match the controller and motor to achieve optimal performance.

Battery voltage must match the motor’s rated operating voltage. Too low voltage causes insufficient power; too high voltage may damage motor windings. Additionally, battery capacity and discharge capability must be compatible with the controller’s maximum current setting to ensure stable power supply under high load conditions.

If the three components are mismatched, consequences can be severe: long-term battery overload accelerates aging, frequent voltage drops affect riding experience, and in serious cases, may trigger thermal runaway, leading to battery fire or explosion.

Purchase Tip: Battery voltage must match the rated voltage of the scooter’s controller and motor.

Battery Degradation in Actual Use

In daily use, you might encounter these frustrating phenomena: a scooter that originally ran 50km (30 miles) now only runs 30km (20 miles), the display shows 20% remaining but suddenly cuts power, hill climbing feels noticeably weaker with frequent protection system activation. These are all typical signs of battery performance degradation.

To understand the essence of these problems, we need to start with the mechanisms of battery voltage, capacity, and heat generation changes.

Voltage Drop

Voltage drop causes sudden power cuts despite seemingly sufficient charge, inadequate power, poor hill climbing, motor shaking, or frequent controller protection activation.

Causes of voltage drop include:

• As discharge progresses, electrochemical reactions gradually lower battery potential
• Increased internal resistance and concentration polarization effects intensify this trend
• When load increases, according to V = V_open_circuit – I ×R_ internal_resistance, output voltage drops significantly
• Temperature changes also affect battery electrochemical activity, with more pronounced voltage drops at low temperatures

Capacity Shrinkage

Capacity shrinkage causes significantly reduced range, more frequent charging, and faster power drain.

Causes of capacity shrinkage include:

• During high-rate discharge, internal chemical reactions cannot keep up with current demand, preventing full capacity release
• In low-temperature environments, slower ion migration prevents full capacity utilization in the short term
• As charge-discharge cycles progress, irreversible structural changes in battery materials gradually reduce capacity
• Additionally, BMS stops discharge when voltage or temperature reaches limits to protect the battery, reducing actual usable capacity

Battery Heating

Battery heating causes warm or even swollen battery cases, and in severe cases, triggers BMS high-temperature protection (automatic power reduction or cutoff) or even fire risk.

Causes of heating include:

• Joule heat (P = I² × R) generated when current passes through internal resistance is the main heat source
• During high-rate discharge, high current causes dramatic heat increase
• Rising temperature further affects battery performance, creating a negative cycle

Types of Electric Scooter Batteries

Common electric scooter battery types include: Lithium-ion (Li-ion), Lithium Polymer (Li-Po), and Lead-Acid batteries.

Lithium-ion Batteries

Characteristics: High energy density, lightweight, long lifespan, fast charging.

Applications: Used in mid to high-end electric scooters, suitable for daily commuting and medium to long-distance riding, ideal for users requiring high performance and portability.

Further subdivisions include Ternary Lithium (NCM/NCA), Lithium Iron Phosphate (LiFePO₄), and Lithium Manganese Oxide (LiMn₂O₄).

Ternary lithium batteries have high energy density but poor thermal stability and higher prices; Lithium Iron Phosphate batteries have slightly lower energy density than ternary lithium but offer high safety and moderate pricing; Lithium Manganese Oxide batteries are significantly inferior in energy density, safety, and lifespan compared to the first two, typically appearing only in low-end, entry-level scooters.

Lithium Polymer Batteries

Characteristics: Flexible design, lightweight and thin, good safety.

Applications: Used in lightweight electric scooters, such as small folding scooters suitable for short-distance commuting.

Lead-Acid Batteries

Characteristics: Heavy, bulky, low cost, short lifespan.

Applications: Found in low-priced electric scooters.

Purchase Tip: Choose the appropriate battery type based on your needs.

In a few years, when high-performance and safer solid-state batteries become widely commercialized, the performance of electric scooters is expected to improve significantly.

Battery Brand Selection and Safety

When choosing batteries, brand is often more important than price. Products from renowned manufacturers like Samsung, LG, and Panasonic have significant safety advantages:

• Use high-quality raw materials and advanced processes
• Built-in multiple protection mechanisms like PTC (Positive Temperature Coefficient thermistor) and CID (Current Interrupt Device)
• Usually equipped with more advanced and reliable BMS (Battery Management System)
• Strict quality control ensures low cell internal resistance and good consistency
• Extensive cycle testing ensures longer service life
• Products pass international certifications like UL and CE, ensuring safety

In contrast, generic batteries often have issues like capacity misrepresentation, use of recycled cells, and lack of safety protection.

Battery Usage and Maintenance Recommendations

Proper usage and maintenance can significantly extend battery life. First, avoid overcharging and over-discharging by keeping charge levels between 20-80%. This reduces stress on battery materials and delays aging.

Temperature management is equally important—avoid use in extreme high or low temperatures. The ideal operating temperature range is 0-40°C. Long-term high-load operation shortens battery life, so avoid continuous hill climbing or high-speed riding.

Regularly inspect battery appearance for swelling, bulging, or leakage safety hazards. For long-term storage, maintain 40-60% charge—neither full charge nor complete discharge—and perform maintenance charging periodically.

Calculation Methods for Purchasing Scooter Batteries

Mastering basic calculation methods helps evaluate whether batteries meet your needs:

• Actual Usable Capacity = Rated Capacity × Utilization Rate
• Total Energy (Wh) = Voltage (V) × Actual Usable Capacity (Ah)
• Range Time = Total Energy (Wh) / Average Power Consumption (W)
• Range Distance = Range Time × Average Speed

Example: A 48V × 20Ah = 960Wh battery, if the scooter travels at constant 25km/h (15mph) with average power consumption of 400W, range time is approximately 2.4 hours with theoretical range of about 60km (37 miles) . However, actual use must consider factors like temperature, road conditions, and riding habits.

Conclusion

As the power heart of electric scooters, the importance of batteries is self-evident. Deep understanding of key parameters like battery voltage, capacity, discharge characteristics, and internal resistance, plus mastering their variation patterns in actual use, forms the foundation for optimizing user experience and making informed purchases.

When selecting batteries, always adhere to the principle of “safety first, brand priority”—don’t overlook safety risks due to price considerations. Comprehensively consider battery voltage, capacity, discharge rate, and suitable battery material types. Through reasonable usage and maintenance, you can not only extend battery life but also ensure riding safety, truly achieving maximum efficiency.

Remember: understanding your battery means understanding your electric scooter; treat your battery well, and it will faithfully serve you longer.

Frequently Asked Questions

1. Is bigger always better for electric scooter batteries?

Not necessarily. While larger capacity provides longer range, it also increases weight, affecting portability and handling. You need to balance range against convenience.

2. Should I choose 36V, 48V, or 60V for my scooter?

Higher voltage means more power, faster acceleration, and better hill-climbing ability, but also higher cost and weight. For urban commuting, 36V or 48V is recommended; choose 60V for high-performance needs.

3. How can I tell if a battery is good quality?

Check the capacity (Ah), brand (like Samsung or LG), certifications, BMS inclusion, and whether specifications are accurate. Prioritize reputable cells from reliable manufacturers.

4. Can I ride an electric scooter in the rain?

Most scooters have basic splash-resistant design (IPX4~IPX6) and can handle light rain, but riding in heavy rain or standing water isn't recommended to prevent motor or battery water damage.

5. Can I take my scooter on buses or subways?

Most lightweight models can be folded and brought onto public transport, but regulations vary by city and operator. Check local rules beforehand.

6. What should I do when my battery's range decreases over time?

This is normal aging. You can slow degradation by avoiding overcharging/over-discharging, high-rate discharge, and extreme temperature use.

7. Why does my scooter lack power going uphill?

This could be due to low voltage, insufficient battery current output, or controller current limiting protection, especially noticeable with aging batteries or heavy loads.

8. Why does my scooter suddenly shut off when the battery still shows charge?

This likely occurs when voltage drops too quickly, triggering BMS protection (low voltage, high temperature, or excessive current), especially common under high load or with aging batteries.

9. Are there issues using e-scooters in winter?

Cold temperatures reduce battery performance, shortening range and weakening power output. Consider pre-warming or avoiding prolonged cold-weather riding.