In this blog post, we will compare and contrast the three most popular types of eBike battery cells: 18650, 26650, and 21700. We will discuss their size, capacity, voltage, weight, cost, and performance differences. We will also provide tips on choosing the suitable battery cell for your eBike based on your needs and preferences.
18650 Battery Cells
18650 battery cells are the most common and widely used eBike battery cells. They are cylindrical and measure 18 mm in diameter and 65 mm in length. They have a typical capacity of around 2500 mAh, a nominal voltage of 3.7 V, a weight of around 45 g, and a cost of about $3 per cell. They can deliver high currents and have a long cycle life.
The main advantage of using 18650 battery cells in an eBike is that they are readily available and affordable. They are also easy to assemble and replace, offering a good balance between power and range. Some disadvantages of using 18650 battery cells in an eBike are that they are relatively heavy and bulky compared to other types of battery cells and have a lower energy density and capacity than newer types of battery cells.
Some popular eBike models that use 18650 battery cells are the Rad Power Bikes RadRunner, the Juiced Bikes CrossCurrent X, and the Aventon Level.
26650 Battery Cells
26650 battery cells are larger and more powerful than 18650 battery cells. They are cylindrical and measure 26 mm in diameter and 65 mm in length. They have a typical capacity of around 5000 mAh, a nominal voltage of 3.7 V, a weight of about 85 g, and a cost of about $5 per cell. They can deliver higher currents and have longer cycles than 18650 battery cells.
The main advantage of using 26650 battery cells in an eBike is their higher energy density and capacity than 18650 battery cells. This means they can provide more power and range for your eBike with fewer cells. Some disadvantages of using 26650 battery cells in an eBike are that they are more expensive and harder to find than 18650 battery cells and are heavier and bulkier than other types of battery cells.
Some popular eBike models that use 26650 battery cells are the Luna Cycle Apex, the Biktrix Juggernaut Ultra FS, and the FLX Blade.
21700 Battery Cells
21700 battery cells are the newest and most advanced type of eBike battery cells. They are cylindrical and measure 21 mm in diameter and 70 mm in length. They have a typical capacity of around 4000 mAh, a nominal voltage of 3.7 V, a weight of around 65 g, and a cost of about $4 per cell. They can deliver higher currents and have longer cycles than 18650 and 26650 battery cells.
The main advantage of using 21700 battery cells in an eBike is that they have the best energy density and capacity among the three types of battery cells. This means they can provide more power and range for your eBike with less weight and space. Some disadvantages of using 21700 battery cells in an eBike are that they are still relatively new and expensive compared to other types of battery cells and may not be compatible with some older or cheaper eBike models.
Some popular eBike models that use 21700 battery cells are the Specialized Turbo Levo SL, the Riese & Müller Supercharger2 GT Rohloff HS, and the Delfast Top Cop.
Compare 18650, 26650, and 21700 cells.
18650, 26650, and 21700 are three common eBike battery cell types that differ in size, capacity, and performance. The numbers indicate the diameter and length of the cylindrical cells in millimeters. For example, a 18650 cell has a diameter of 18 mm and a length of 65 mm.
The main advantage of 18650 cells is that they are widely available and affordable. They have been used for years in various applications, such as laptops, flashlights, and electric vehicles. However, they also have some drawbacks, such as lower capacity, higher internal resistance, and shorter lifespan than newer types of cells.
26650 cells are larger and heavier than 18650 cells but offer higher capacity and lower internal resistance. This means they can store more energy and deliver more power than 18650 cells. They are also more durable and safer than 18650 cells. However, they are also more expensive and less compatible with some eBike models.
21700 cells are the newest and most advanced type of eBike battery cells. They have a similar diameter to 18650 cells but a longer length of 70 mm. They offer the best of both worlds: high capacity, low internal resistance, long lifespan, and reasonable cost. They are also compatible with most eBike models. However, they are still not as widely available as 18650 cells.
The table below summarizes the key differences between the three types of eBike battery cells:
| Type | Diameter (mm) | Length (mm) | Capacity (mAh) | Internal Resistance (mΩ) | Lifespan (cycles) | Cost ($) |
|——|—————|————-|—————-|————————-|——————-|———-|
| 18650 | 18 | 65 | 2000-3500 | 20-40 | 300-500 | 2-5 |
| 26650 | 26 | 65 | 4000-5000 | 10-20 | 500-800 | 5-10 |
| 21700 | 21 | 70 | 3000-5000 | 5-10 | 800-1000 | 3-7 |
How to Choose the Right Battery Cell for Your eBike
Choosing the right battery cell for your eBike depends on your needs and preferences. Here are some factors to consider:
Range:
How far do you want to ride your eBike on a single charge? The higher the capacity of the battery cell, the longer the range of your eBike. However, you also need to consider the weight and size of the battery pack. A larger and heavier battery pack may reduce your eBike’s performance and handling.
Power:
How fast and powerful do you want your eBike to be? The lower the internal resistance of the battery cell, the higher the power output of your eBike. However, you also need to consider the compatibility and safety of the battery pack. A higher power output may require a higher voltage or current rating of your eBike’s controller and motor. A higher power output may also generate more heat and stress on the battery pack.
Weight:
How much do you care about the weight of your eBike? The lighter the battery cell, the lighter the battery pack. A lighter battery pack may improve your eBike’s performance and handling. However, you also need to consider the capacity and durability of the battery pack. A lighter battery pack may have a lower capacity and shorter lifespan than a heavier battery pack.
Cost:
How much are you willing to spend on your eBike’s battery pack? The cheaper the battery cell, the cheaper the battery pack. A cheaper battery pack may save you money upfront. However, you also need to consider the quality and reliability of the battery pack. A more affordable battery pack may have lower performance and a shorter lifespan than a more expensive one.
Choosing the right battery cell for an eBike depends on range, power, weight, and cost. A higher-capacity battery cell will offer a more extended range, while a battery cell with lower internal resistance will provide more power output. A lighter battery cell can improve the eBike’s handling and performance but may have a lower capacity and shorter lifespan. Cheaper battery cells may save money upfront but have lower performance and reliability.
Final Thoughts on Choosing the Right Battery Cells for E-Bikes
Choosing the right battery cell for your eBike depends on your needs and preferences. While 18650 cells are widely available and affordable, 26650 cells offer higher capacity and lower internal resistance. 21700 cells are the newest and most advanced, with high capacity, low internal resistance, long lifespan, and reasonable cost. Factors to consider when choosing a battery cell include range, power, weight, and price.
Sales Manager at Jieli Electric Bikes.
Near 10 years experience in electric bike industry, researching/marketing/promoting e-bike is my daily life.
