What Battery Size is Best for Your Electric Bike?

May 27, 2024

What Battery Size is Best for Your Electric Bike?

Choosing the right battery size is key to optimizing your e-bike experience. It affects range, weight, handling, and performance. A good match ensures you have enough power for your rides without needing to recharge constantly, striking a balance between efficiency and performance.

Key Takeaways

  • The best e-bike battery size depends heavily on individual needs, factoring in your usual riding distances, the power of your bike’s motor, desired bike handling, and weight distribution. 
  • Ensure the battery's voltage, connector type, and physical size perfectly match your e-bike. Improper fit can be dangerous and damage components. 
  • Proper maintenance, including correct charging and storage practices, maximizes a battery's lifespan and performance.
  • Don't just focus on the highest capacity. Security features, weight, and user-friendliness can be just as important for everyday riding enjoyment.
  • Top batteries for electric bikes include the Unit Pack Power Official E-Bike Battery, the Yose Power Electric Bike Battery, and the Joyisi Electric Bike Battery.

This article breaks down the key factors to consider, helping you decide to achieve the perfect balance of size, power, and range for your e-bike adventures.

Understanding Electric Bike Batteries

The battery serves as the heart of your electric bike, powering you through hills, extending your riding range, and transforming a standard bicycle into a fun and efficient ride. Given the variety of e-bike batteries on the market, selecting the right one can seem daunting. 

When evaluating e-bike batteries, you'll encounter several important specifications that determine their fit for your needs:

Capacity (Ah): Imagine your battery's Ah rating as the size of a gas tank. The higher the Ah, the farther you can travel on a single charge, offering a longer range.

Voltage (V): Think of voltage as the water pressure in your tank. Higher voltage translates to more power, enabling quicker acceleration and stronger performance on hills.

Watt-hours (Wh): This combines both Ah (capacity) and V (voltage) (Wh = V x Ah). It represents the battery's overall capability. A higher Wh rating signifies a greater range and the ability to deliver more power to the motor when needed, tackling demanding terrains with ease.

Types of Electric Bike Batteries

Here's a look at the most common types of batteries used in electric bikes today:

Lithium-ion Batteries: The reigning champion of e-bike batteries, lithium-ion offers an excellent combination of energy density (how much power they hold for their size), lifespan, and weight. They are the most common type due to their versatility and performance.

Lead-acid Batteries: These older-style batteries are heavier and have a shorter lifespan than lithium-ion. However, they're a more budget-friendly option. You might still see these on some lower-cost e-bikes or older models.

Nickel-metal Hydride (NiMH) Batteries:These batteries offer a middle ground between lead-acid and lithium-ion. They are lighter than lead-acid but not as powerful or long-lasting as lithium-ion. You might find these on older e-bikes or models where weight is a primary concern.

Here's a comparison table summarizing their pros and cons:

Types of Electric Bikes - A Comparison

Top Batteries for Electric Bikes

Battery Name Capacity (Ah) Suitable Motor Power Max Discharge Current Compatibility Key Features
Unit Pack Power Official 36V - 10Ah 200W - 700W (peaking at 500W) 25A Various (if voltage matches)
  • Integrated lock
  • Charge indicator
  • Water-resistant
  • USB port
  • On/off button
Engwe 48V - 12.5Ah Engwe EP-2, EP-2 PRO, ENGINE PRO only Not explicitly stated Engwe EP-2, EP-2 PRO, ENGINE PRO only
  • Removable, integrated lock
  • Specific safety recommendations
Yose Power 36V - 13AH 100W - 700W 10A standard, 20A max Various (if motor/voltage matches)
  • 78% capacity after 1000 cycles claim
  • Quick charge
  • Flexible return policy
Joyisi 48V - 15Ah 350W - 1000W 30A continuous Various (if motor/voltage matches)
  • High-quality cells, fuse, BMS
  • Rack-mountable
  • Anderson connectors
MXS 48V - 13Ah 250W - 1000W 30A continuous Wide motor compatibility, including Bafang
  • BMS
  • USB port
  • LED indicator
  • Anderson connectors


This section gives you an overview of the best batteries on the market, considering factors like capacity, battery longevity, and features to help you find the ideal fit for your electric adventures.

1. Unit Pack Power Official E-Bike Battery

This Unit Pack Power battery offers a 36V 10Ah capacity, making it suitable for motors ranging from 200W to 700W (with an ideal peak of around 500W). It can handle a maximum discharge current of 25A and weighs around 3.85 kg. A 42V 2A charger is included.  

The battery also utilizes lithium-ion cells and incorporates features such as an integrated lock, charge indicator, water-resistant design, USB charging port, on/off button, and an LED power indicator.

Unit Pack Power Official E-Bike Battery

The Unit Pack Power Official Battery is likely an excellent fit for riders who prioritize security, everyday convenience features, and the reassurance of a well-known brand. Those seeking the absolute lightest battery may want to compare weights with other options.

It's also fantastic that they mention working with Samsung, LG, and Sanyo, enhancing trust in the cell quality. The one-year warranty is also a great sign for buyers.


  • The integrated lock offers theft deterrence.
  • Features like the USB port, on/off switch, and battery level indicator enhance convenience.
  • Suited for a range of motors and backed by a 1-year warranty.


  • While not explicitly stated, larger capacities from this brand could be heavier than some competitors.
  • Features and brand reputation might contribute to a slightly higher price point. 

2. Engwe Electric Bike Battery

Engwe manufactures its own batteries specifically for its EP-2, EP-2 PRO, and ENGINE PRO e-bike models. These batteries are integrated and convenient, providing a reliable power source for Engwe bikes. The brand emphasizes safe charging practices and protection against over-discharge, which extends the battery's life. However, their compatibility is limited to specific models, which is important to consider before buying.

Engwe Electric Bike Battery

An Engwe battery has a capacity of 36/48V 10Ah to 15Ah and takes about 5 hours to fully charge, offering a range of 35-40 miles with pedal assist. Features include a removable design with an integrated lock and safety-focused charging guidelines from the manufacturer.

The Engwe Electric Bike Battery offers a straightforward and integrated solution for those with compatible Engwe models. Those who need more flexibility or have other brands of e-bikes should look at different options.


  • Designed to perfectly fit and work with specific Engwe e-bikes.
  • The integrated lock provides peace of mind when leaving the bike unattended.
  • Suitable for many commutes and leisure rides.


  • Only fits select Engwe models, restricting options for those with other brands of e-bikes.
  • Finding replacements or spares down the line might be reliant on Engwe's stock.

3. Yose Power Electric Bike Battery

Yose Power offers an impressive e-bike battery option emphasizing durable performance and user-friendly features. The company prioritizes reliability and safety, enhancing the overall appeal of its products.

The Yose Power battery has a 36V 13Ah capacity, with a standard discharge current of 10A and a maximum of 20A, making it compatible with motors ranging from 100W to 700W. It takes about 7 hours to charge using the smart charger fully. Additional features include a safety lock, an LED battery indicator, and a power-saving switch.

Yose Power Electric Bike Battery

This battery is ideal for riders who value longevity and safety and might also appreciate Yose Power's flexible return policy. It's important to ensure compatibility with your specific motor.

Yose Power claims the battery retains 78% of its capacity after 1000 charge cycles, a strong testament to its quality. This and a flexible return policy make it an attractive choice for those uncertain about their purchase.


  • Thorough testing and the promise of maintained capacity even after 1000 cycles boost confidence in the battery's lifespan.
  • The safety lock and detailed instructions demonstrate attention to safe practices.
  • The 7-hour charge time is reasonably fast for getting you back on the road.
  • While batteries can be tricky to return, Yose Power's policy is consumer-friendly.


  • Potential compatibility questions: It's best to double-check with Yose Power if unsure about your specific e-bike's compatibility.

4. Joyisi Electric Bike Battery

Joyisi has introduced a powerful e-bike battery designed for compatibility with higher-wattage motors and equipped with robust safety features.

The Joyisi battery features a 48V 15Ah capacity and is built with high-quality 18650 lithium-ion cells. It is suitable for motors ranging from 350W to 1000W and offers a 30A continuous discharge capability. The package includes a 54.6V 2A charger. Additional features include Anderson connectors and a sturdy, rack-mountable case. Key safety features are a fuse, a 30A BMS (Battery Management System) protection board, and a lockable on/off switch.

Joyisi Electric Bike Battery

The Joyisi Electric Bike Battery is an excellent option for riders with powerful motors who need a well-protected and relatively easy-to-install battery. Riders concerned about weight may want to consider lighter alternatives.


  • Ideal for those with e-bikes demanding more power for hills or heavier loads.
  • The fuse, BMS, and lockable power control demonstrate attention to safety.
  • The rack-style design likely simplifies mounting for many e-bike setups.
  • The 1-year warranty and US-based technical support offer peace of mind.


  • While not explicitly stated, higher-capacity batteries in rack designs can sometimes add more weight than other form factors. 

5. MXS E-bike Battery

MXS offers a versatile option that strongly focuses on widespread motor compatibility and features that enhance convenience and safety.

This MXS battery features up to 52V 17.5AH capacity, handles up to a 30A continuous discharge, and is suitable for a wide range of motors from 250W to powerful 1000W setups. Dimensions are 14.4 inches in a downtube form factor. Additional features include a 54.6V 2A charger, Anderson discharge connector, USB port, LED battery level indicator, and a robust 30A BMS protection system.

MXS E-bike Battery

The MXS E-bike Battery is a solid choice for riders seeking broad compatibility with various e-bike motors who value safety and appreciate convenient features.

The long warranty lifespan is also impressive and inspires confidence. It would be worth verifying with MXS if the connector can be swapped upon request if Anderson isn't the best fit for your e-bike.


  • Its support for motors of various power levels, including popular brands like Bafang, is a major advantage.
  • The 30A BMS and safety testing demonstrate attention to safe operation.
  • The USB port and LED battery indicator add everyday usefulness.


  • While Anderson is versatile, it would be helpful if MXS also offered other connector choices.

Choosing the Right Battery for Your Needs

The perfect e-bike battery isn't a one-size-fits-all solution. Selecting the right battery for your needs ensures you get the most enjoyment and practicality out of your e-bike adventures. Let's consider some essential factors influencing your decision.

Your journeys:Understanding the typical distance and terrain of your rides is crucial. Longer rides or those with lots of hills and challenging terrain will naturally demand a higher-capacity battery to avoid running out of juice. If your rides are mostly short commutes or leisurely spins on flat ground, a lower-capacity (and often lighter/cheaper) battery could be sufficient.

Your bike's power: Your e-bike's motor plays a significant role. More powerful motors generally draw more energy from the battery, meaning you might need a higher-capacity battery to achieve the same range as a less powerful setup. It's also important to ensure the battery's voltage and discharge current match your motor's requirements for optimal performance.

Weight and placement:E-bike batteries add weight, affecting handling. Battery placement (rack, frame) impacts weight distribution. Some riders prefer lighter batteries for better handling, even at the cost of some range. Others prioritize range and are less bothered by extra weight. Consider how weight and placement suit your riding style.

Compatibility with your electric bike:E-bike battery compatibility is crucial. Mismatched components can damage the bike or fail. Match the motor voltage (usually 36V or 48V) and connector type. Ensure the battery fits securely in the mount.

Take note that choosing a compatible battery isn't just about it working – safety and the longevity of your e-bike are at stake. Taking the time to ensure proper fit is an investment in your safety and the long-term health of your e-bike.

How to Check E-Bike Battery Compatibility

Battery Maintenance and Safety Precautions

Taking care of your e-bike battery is crucial for getting the most out of it, both in terms of lifespan and performance. Here are some essential tips to keep your battery in top condition:

  • Avoid extreme temperatures. Store your battery in a cool, dry place when not in use. Ideally, keep it around room temperature.
  • Don't store a fully depleted or fully charged battery for extended periods. Aim to keep it around 40-70% charge for long-term storage.
  • Batteries like to be used! Letting it sit idle for months can harm it. Try to use and partially recharge it at least every few weeks.
  • Regularly draining your battery to 0% puts wear on the cells. Try to keep it above 20% most of the time.
  • Extreme heat or cold harms batteries. Avoid riding in extreme conditions and charge at room temperature.
  • Invest in the charger recommended by the battery or e-bike manufacturer. Cheap chargers can damage cells over time.
  • It's usually better to top off the battery more frequently than fully drain and recharge it.
  • Remove the battery from the charger once it's full. Prolonged charging can degrade the battery.
  • Consult the battery's manual for specific charging recommendations and safety guidelines.
  • Never puncture, drop, or strike the battery; damaging the cells can lead to hazardous situations. 
  • Protect your battery from water, as exposure can cause dangerous short circuits.
  • If your battery also releases smoke, a burning smell, begins to swell, or leaks, immediate action is needed. Stop charging and, if possible, move it outdoors to a safe area. Monitor closely and contact the manufacturer for guidance. 

Remember, many manufacturers provide detailed safety guidelines on their websites or with the battery. Familiarizing yourself with these resources ensures you always handle your e-bike battery with maximum safety practices in mind.

The Bottom Line

Your electric bike's battery is its heart, determining both the range and overall enjoyment of your rides. Choosing the right battery size isn't about just finding the biggest capacity – it's about finding the ideal balance of power, compatibility, features, and reliability that aligns with your specific needs. 

Remember, the right battery lets you focus on the joy of the ride and not worry about running out of power or compatibility issues. Invest some time in the selection process, and the payoff will be miles and miles of e-bike smiles.

What Size Battery Is Best for Your Electric Bike?

FAQs: Best Battery for Electric Bike

What is the lifespan of an e-bike battery?

Lithium-ion e-bike batteries generally last between 3-5 years if well-maintained. However, this lifespan depends on factors like the battery's quality, how often you ride, storage practices, and how deeply you discharge the battery between charges.

Can I put a stronger battery in my e-bike?

This depends on your e-bike's motor and controller. Increasing the battery voltage (e.g., from 36V to 48V) might damage your system if it's not designed for that power. Sometimes, a higher-capacity battery with the same voltage is possible, but it's crucial to check compatibility with your specific e-bike's setup first.

Is it bad to leave the e-bike battery fully charged?

It's not ideal for long-term storage. Lithium-ion batteries are happiest when partially charged.  For extended periods when you won't be using the bike, storing the battery at around 40-70% charge is better for its longevity.

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