Last Updated on October 22, 2023 by Kevin Chen
Image source Apogee
The 18650, 26650, and 21700 batteries are all types of rechargeable lithium-ion batteries. They are commonly used in a variety of applications, such as flashlights, power tools, and electric vehicles.
Each type of battery has its own unique characteristics that make it suitable for different applications. In this article, we will discuss the differences between 18650, 26650, and 21700 batteries and how they can be used in various applications.
18650 Battery
The 18650 battery is one of the most popular types of rechargeable lithium-ion batteries. It is commonly used in flashlights, power tools, and electric vehicles. The 18650 battery has a diameter of 18mm and a length of 65mm, which makes it relatively small and lightweight. It has a capacity of up to 3,000 mAh and can be recharged up to 500 times. The 18650 battery is also relatively inexpensive and widely available.
18650 Technical parameters
To give you a better understanding, let’s look at the key technical parameters of the 18650 battery.
-Nominal voltage: The battery has
a nominal voltage of 3.7V.
-Capacity: The capacity of the 18650 battery is up to 3,000 mAh.
-Recharge cycles: The battery can be recharged up to 500 times.
-Size: The 18650 battery has a diameter of 18mm and a length of 65mm.
-Charging voltage:The charging voltage of the 18650 battery is 4.2V.
-Charging current: The battery has a charging current of 0.5C.
-Minimum discharge current: Its minimum discharge current is 1C
-Charging time: It takes approximately 3 hours for the cell to be fully charged
-Battery cell weight: The average weight of this battery cell is 48g
-Lifespan: The battery has a lifespan of between 300 to 500 cycles
-Charge methods: The cell uses constant current (CC) and constant voltage (CV) charging methods.
-Storage temperature:The 18650 battery should be stored at a temperature between -20°C and 45°C.
26650 Battery
The 26650 battery is a larger version of the 18650 battery. It has a diameter of 26mm and a length of 65mm, making it slightly larger and heavier than the 18650 battery. The 26650 battery has a capacity of up to 6,000 mAh and can be recharged up to 500 times. It is more expensive than the 18650 battery but is still widely available.
26650 Technical parameters
Here are the key technical specifications of the battery.
-Nominal voltage: The battery has a nominal voltage of 3.7V.
-Capacity: The capacity of the battery cell ranges between 3000 mAh to 3100 mAh.
-Recharge cycles: The battery cell can be recharged up to 2000 times.
-Size: The 26650 battery has a diameter of 26mm and a length of 65mm.
-Charging voltage: The charging voltage of the 26650 battery is 4.2V.
-Battery weight: It approximately weights 92g
-Pulse discharge current: The pulse discharge current of the 26650 battery is up to 10C.
-Charge methods: The cell uses CC and CV charging methods.
-Storage temperature: The 26650 battery should be stored at a temperature between -20°C and 45°. Starts discharging at temperatures of between 20°C and 60°C.
21700 Battery
The 21700 battery is the newest type of rechargeable lithium-ion battery. It has a diameter of 21mm and a length of 70mm, making it slightly smaller and lighter than the 18650 and 26650 batteries. The 21700 battery has a capacity of up to 4,000 mAh and can be recharged up to 500 times. It is more expensive than the 18650 and 26650 batteries but is still widely available.
21700 Technical specifications
Here are the key technical specifications of the battery.
-Nominal voltage: The battery has a nominal voltage of 3.7V.
-Capacity: The capacity of the cell is between 3900 and 5600 mAh.
-Recharge cycles: The battery has charge and discharge cycles of between 500 to 2000.
-Size: The battery has a diameter of 21mm and a length of 70mm.
-Charging voltage: The charging voltage of the 21700 battery is 4.2V.
-Battery weight: It approximately weights 60g
-Cutoff voltage 2-2.5V
-Capacity discharge_ It has a discharge is 0.2C
-Pulse discharge current: The pulse discharge current of the 21700 battery is up to 10C.
-Charge methods: The cell uses constant current (CC) and constant voltage (CV) charging methods.
-Charging time: The battery takes approximately between 2.5hrsto 3 hrs to be fully charged.
-Charge density: It has a charge density of 10.5-13.7Wh
-Storage temperature: The 21700 battery should be stored at a temperature between -20°C and 55°C. Starts discharging at temperatures of between 20°C and 60
18650 VS 26650 VS 21700 Battery: What’s The Difference?
Let’s now compare the three battery cells using various key parameters. From this detailed comparison, you will know which one is more suitable for your application.
Nominal voltage
The nominal voltage of a battery refers to the voltage at which the battery is designed to operate. All three batteries have an average nominal voltage of 3.7V. There is no significant difference in terms of the nominal voltage of the three batteries.
Capacity
The capacity of a battery refers to the amount of energy it can store. The 18650 battery has a capacity of up to 3,000 mAh, while the 26650 and 21700 batteries have capacities of up to 6,000 mAh and 4,000 mAh, respectively. This means that the 26650 and 21700 batteries have higher capacities than the 18650 battery.
Recharge cycles:
The recharge cycles of a battery refer to the number of times it can be recharged before it needs to be replaced.
It is the lifespan of a battery cell.
From the specifications above, the 26650 and 21700 have a way superior charge cycle than the 18650 battery. cell.
Size
The size of a battery refers to its diameter and length. The 18650 battery has a diameter of 18mm and a length of 65mm, while the 26650 and 21700 batteries have diameters of 26mm and 21mm, respectively, and lengths of 65mm and 70mm, respectively. So, if your application is quite sensitive on size, you will have to compare the three and choose the right size from the three.
Weight
The weight of a battery refers to how much it weighs. The 18650 battery has an average weight of 48g, while the 26650 and 21700 batteries have weights of 92g and 60g, respectively. This means that the 18650 battery cell is the lightest of the three. Are you curious about the weight of the cells? You now know the right option.
Discharge current
Discharge current is the amount of current that can be drawn from the battery. The 18650 battery has a minimum discharge current of 1C, while the 26650 and 21700 batteries have pulse discharge currents of up to 10C. This means that the 26650 and 21700 batteries can provide more power than the 18650 battery.
Charging method
As we have seen, all three batteries use constant current (CC) and constant voltage (CV) charging methods. This means that they can be charged using the same type of charger.
Storage temperature
The storage temperature of a battery refers to the temperature at which it should be stored. The 18650, 26650, and 21700 batteries should be stored at temperatures between -20°C and 45°C, -20°C and 45°C, and -20°C and 55°C, respectively. This means that the 21700 battery can be stored at a higher temperature than the other two batteries.
Charging time
How long does it take to charge these battery cells? The 18650 battery takes approximately 3 hours to be fully charged, while the 26650 and 21700 batteries take approximately 2.5 hours and 3 hours, respectively. This means that the 21700 battery has a slightly longer charging time than the other two batteries.
But generally, there is a very small difference when it comes to the charging duration of the three cells.
Chemical composition
Of course, the three are all lithium-ion batteries, but they have different chemical compositions. The 18650 battery is composed of lithium cobalt oxide (LiCoO2), while the 26650 and 21700 batteries are composed of lithium iron phosphate (LiFePO4). This means that the 26650 and 21700 batteries are more stable and have a longer lifespan than the 18650 battery.
Charge density
The charge density of a battery cell is the amount of energy it can store per unit of weight. The 18650 battery has a charge density of 8.5-10.5Wh, while the 26650 and 21700 batteries have charge densities of 10.5-13.7Wh and 10.5-13.7Wh, respectively. This means that the 26650 and 21700 batteries have higher charge densities than the 18650 batteries.
Cutoff voltage
The cutoff voltage of a battery refers to the voltage at which it should be disconnected from the charger. The 18650 and 26650 batteries have cutoff voltages of 2.5V, while the 21700 battery has a cutoff voltage of 2-2.5V. This means that the 21700 battery has a slightly lower cutoff voltage than the other two batteries.
Inner resistance:
The inner resistance of a battery refers to the resistance of the cell when it is in use. The 18650, 26650, and 21700 batteries have inner resistances of between 10-20mΩ, 10-20mΩ, and 5-10mΩ, respectively. This means that the 21700 battery has a lower inner resistance than the other two batteries.
Continuous discharge current
This refers to the amount of current that can be drawn from the battery continuously. The 18650 and 26650 batteries have continuous discharge currents of 1C, while the 21700 battery has a continuous discharge current of 0.2C. This means that the 21700 battery can provide less power than the other two batteries.
Applications
When it comes to the usage, the 18650 battery is mostly used in flashlights, power tools, and electric vehicles. The 26650 battery is used in high-powered applications such as electric bikes and scooters. The 21700 battery is used in applications that require a higher capacity and longer lifespan, such as solar energy storage systems. So, you can choose the right battery cell depending on your application.
Cost
What about the price of the battery cell? The 18650 battery is the most affordable of the three, while the 26650 and 21700 batteries are more expensive. So, if you are looking for a budget-friendly option, then the 18650 battery is your best bet. However, keep in mind that the price will always depend on the quality and brand of the battery. It will also depend on the battery supplier that you choose.
FREQUENTLY ASKED QUESTIONS
Now let’s look at the most common questions that people tend to ask with regards to the 18650, 26650, and 21700 batteries.
Are AA batteries the same as 18650?
No, AA batteries are not the same as 18650 batteries. AA batteries are smaller and have a lower capacity than 18650 batteries. The two also tend to have different chemical composition.
Can I use a 26650 battery in place of a 18650 battery?
Yes, you can use a 26650 battery in place of a 18650 battery. However, keep in mind that the 26650 battery is larger and heavier than the 18650 battery.
Can I use a 21700 battery in place of an 18650 battery?
Yes, you can use a 21700 battery in place of a 18650 battery. But you should keep in mind that the 21700 battery is larger and slightly heavier than the 18650 battery. So, your device or application should be designed to keep up with these new changes.
Why are the 18650 batteries so popular?
The 18650 battery is popular because it is relatively small and lightweight, has a high capacity, and is relatively inexpensive. It is also widely available and can be used in a variety of applications.
What makes 18650,21700 and 26650 batteries explode?
The 18650, 21700, and 26650 batteries can explode if they are overcharged, short-circuited, or exposed to extreme temperatures. It is important to use the right charger and follow the manufacturer’s instructions when charging these batteries.
Is C battery the same as 26650 battery?
No, C batteries are not the same as 26650 batteries. Even though they are of the same size, C batteries are not rechargeable and have a much lower capacity than 26650 batteries.
Conclusion
Well, there you have it. Now you know all about the 18650, 26650, and 21700 batteries. You know their key technical specifications, how they compare to each other, and what applications they are suitable for. So, you can now make an informed decision when choosing the right battery cell for your application. And planning to buy these rechargeable lithium-ion batteries in China? Consider contacting ICRFQ. We are a reputable supplier of 18650, 26650, and 21700 batteries. We offer high-quality products at competitive prices. Contact us today for more information.
If you want to find more Electronic Components Distributors, please check out the following articles:
Electronic Components Distributors In the USA
Electronic Components Distributors In UK
Electronic Components Distributors In China
Electronic Components Distributors In India
Electronic Components Distributors In Singapore
Electronic Components Distributors In Malaysia
Electronic Components Distributors In Vietnam
Electronic Components Distributors In South Korea
- Where to buy IC chips? The Best Guide? - March 26, 2024
- Breaking Down Barriers: Overcoming Obstacles in Cross-Border Electronic Component Trade - March 4, 2024
- Everything You Need to Know About Amplifier IC Chips - March 4, 2024
