In recent years, with the vigorous development of electric vehicles and other means of transportation, lithium rechargeable batteries have become more and more popular, and the application of 21700 batteries has become more and more extensive, so the number of 21700 batteries is gradually increasing. Of course, the 18650 battery is also very famous because it was the standard in the past and is still used in many industries. We are often asked about the difference between 18650, 20700, and 21700 batteries, which one is better?
Therefore, we will introduce you to these three battery technologies.
First of all, it can be said that both 18650 and 21700 batteries are based on lithium technology. Lithium batteries have high energy density, 1.5 to 2 times the capacity of NiMH batteries of the same weight, and low self-discharge electrodes, making them very popular in electric vehicles and other technology products. The most common cylindrical lithium batteries now are 18650 and 21700 batteries.
18650 is the original size of the battery. 18 represents the diameter (18mm), 65 represents the length (65mm), and 0 represents the shape (cylindrical). 18650 batteries are very common in daily life.
⭐Mature production process and good battery stability
18650 batteries have been used in electronic products for a long time and are the oldest, most mature and most stable lithium batteries. Other technologies, such as stacked lithium batteries, are not yet mature enough, and many products are not even consistent in size, or the production processes available to battery manufacturers do not meet quality standards.
The 18650 lithium battery complies with high safety standards. Non-explosive, non-flammable, environmental compatibility is superior to other technologies. In addition, 18650 technology has passed RoHS certification. This kind of battery has good high temperature resistance and 100% discharge efficiency at 65 degrees. Cases are usually made of steel to minimize problems even in extreme situations such as car accidents.
⭐High energy density
The capacity of 18650 lithium battery is usually between 1200~3600mAh, while the capacity of other batteries is only about 800mAh. The capacity is 1.5-2 times that of Ni-MH batteries of the same weight.
The 18650 lithium battery has a long service life and can be cycled more than 500 times under normal use, which is more than twice that of conventional batteries. The technology has matured so that manufacturing can be optimized and operating and maintenance costs can be reduced.
Although 18650 batteries have been widely used for many years and are more mature than other types of batteries, they also have disadvantages such as high heat generation, complicated grouping, and slow charging time. The 21700 cells are also cylindrical, so that's logical too. 21 represents a diameter of 21mm, 70 represents a length of 70mm, and 0 represents a cylindrical shape. Compared with the 18650 lithium battery, the capacity of the 21700 battery is increased by more than 35% under the same weight.
⭐High energy density
The energy density of 21700 cells is better than that of 18650 cells, which ensures higher capacity.
⭐Reduce manufacturing cost
Because 21700 cells have a higher energy density, fewer parts and equipment are required to produce the same number of cells. This results in lower production costs.
As with most cylindrical batteries, the first two digits represent the diameter of the battery, followed by the height of the battery, with 0 indicating the cylindrical shape. So the diameter of the 20700 battery is 20mm and the height is 70mm.20700 cells are less common than 18650 technology, but have found wider use in e-cigarettes due to their advantages.
Compared with the 21700 battery, there are many similarities. The biggest difference is the size of the two batteries, as the 20700 is 1mm smaller in diameter. There is hardly any difference in weight and energy density, which is why we summarize the two battery formats here for comparison with 18650 batteries.
20700/21700 VS 18650 battery
Olight sells flashlights with two battery types, because the smaller diameter and lighter weight of 18650 batteries make the flashlight more compact and lighter, which is an advantage for everyday use.For example, the Warrior Mini 2 with 1750 lumens is worth mentioning.Of course we also have flashlights in our range with 21700 batteries and almost always with 5000 mAh batteries in order to be able to combine with the high efficiency LEDs to give you the longest run time possible.The Seeker 3 Pro with 4200 lumens and 4 LEDs for large area lighting is a good example.
Advantages of 21700/20700 batteries
1.Larger capacity and performance: The capacity of 21700/20700 is around 4000-5000mAh, while 18650 battery is usually around 1200-3600mAh. A bigger battery means the device will run longer. In fact, 20700 batteries have a higher amperage rating, supporting 30-45 amps of continuous discharge, allowing them to run longer at higher wattages. With an 18650 battery the limit is about 30 amps. Batteries with greater capacity and power are a good choice for e-cigarettes and flashlights, and even for electric vehicles.
2.Longer battery life: Thanks to the advanced lithium-ion technology, the 20700/21700 battery has a longer life, and can be cycled more than 500 times in normal use.
Disadvantages of 21700/20700
1.Manufacturing cost is higher than 18650: There are much less 20700/21700 batteries on the market. Due to the underdevelopment of large-scale production, the production cost is significantly higher than that of 18650 batteries with more advanced production technology and larger production scale.
2.Fewer devices: 20700 batteries are compatible with fewer electronics, but that should change in the future.
Is there anything worth noting about handling batteries?
1.The battery is not waterproof and cannot be exposed to moisture.
2.Please do not put the battery in an extremely hot place, such as inside a car or under direct sunlight.
3.Do not use a damaged battery, and make sure that the battery cannot be in contact with metal objects to avoid a short circuit. For example in pockets containing keys, change, or other metal objects.
4.Beware of counterfeit products, do not buy cheap batteries. It is best to only buy batteries from reliable websites.
5.Please use a compatible charger and make sure to purchase the correct battery for your product. For example, if you are buying replacement batteries for Olight products, please choose batteries sold by Olightstore, because we use custom batteries in our products, which have advantages such as higher capacity, magnetic charging, etc. If you are not sure which battery is suitable for your flashlight, please feel free to contact our customer service.
Olight sells flashlights with two batteries, because the smaller diameter and lighter weight of 18650 batteries make the flashlight more compact and lighter, which is an advantage for daily use. For example, the Warrior Mini 2 with 1750 lumens is worth mentioning.
Of course we also have flashlights with 21700 batteries in our range and almost always use a full 5000 mAh battery to be able to combine with the high efficiency LEDs to give you the longest run time possible. The Seeker 3 Pro with its large area lighting of 4200 lumens and 4 LEDs is a good example.