Everything You Need to Know About 18650 Lithium-ion Batteries

How much do you know about 18650 lithium-ion batteries/18650 cells? Being slightly larger than those regular A size batteries, a 18650 battery shares similar looks with those one-time use/disposable batteries commonly seen on shelves. However, the difference between them is huge. Even among rechargeable batteries, the 18650 battery has been unique both in features and application.

If you are not too familiar with these small yet wonderful batteries, this article is a good start for a glance at their definition, advantages, and applications. After reading it, hopefully, you will have a deeper understanding of 18650 lithium-ion batteries.

What Are 18650 Lithium-ion Batteries, Exactly?

Let’s start with the name. The number 18650 has a meaning and is broken down as follows:

• The first two numbers (18) refer to the battery's diameter in millimeters.

• The following two numbers (65) stand for the length of the battery, also in millimeters.

• The final number (0) represents the battery's round shape.

The most common voltage for 18650 lithium-ion batteries is typically 3.6v, with the capacity ranging from 1800mAh to 3500mAh (Milliamp Hour).

Despite the fact the 18650 lithium-ion battery is rechargeable, it does not last forever, and the life cycle varies from battery to battery. Generally speaking, most 18650 lithium-ion batteries possess approximately 300-500 charge cycles, for some with super long cycle life, such as EVE’s 18650 Cylindrical Cell, its cycle life can even reach 800 cycles! Within their life cycles, the batteries can be charged to 80% or to 100% of their set capacity. Once a battery’s maximum life cycle is reached, the capacity will slowly decrease over time until the battery is used. It is essential to store, charge, and use batteries within their recommended temperature range. Extreme hot or cold temperatures can affect the life of a lithium-ion battery.

The Advantages & Applications of the 18650 Lithium-ion Batteries

Over the past few decades, lithium-ion batteries have been increasingly used in electronics. The reasoning for the increased use is due to:

• The high reliability of each battery.

• The long recharge cycle life.

• Each battery’s a high safety rating.

• The high energy capacity of each battery.

• The light weight of each battery.

• Each battery has no memory effect, which extends the life of each battery.

The Performance of the 18650 Battery

The 18650 lithium-ion battery is a workhorse with many advantages making it a popular choice for use in electronics.

1. Long usage time & high reliability

The EVE 18650 33V battery was designed to be used for extended periods. Average batteries have a capacity of 800 mAh, which is an excellent fit for accessories that are not heavily used. More than 800 mAh is required for other applications requiring high usage. Each EVE 18650 battery has a capacity of 3200 mAh, making it a solid choice for tools, toys, and other applications needing long-term power.

2. Long cycle life

As previously mentioned, the cycle life of most 18650 lithium batteries is 300-500 charge cycles, which is already double those of ordinary batteries. EVE’s 18650 33V Cylindrical Cell is even better, since it works in a wide temperature range, from -20˚ to 70˚ Celsius, more than just at room temperature. This feature is especially necessary when it comes to outdoor power storage, some of which are located in areas with extreme temperatures that may otherwise damage the regular batteries.

3. High Safety

Safety is always the primary concern in all situations. Fortunately, you can count on 18650 lithium batteries regarding their safety. To prevent the battery from short-circuiting, its positive and negative electrodes are separated, minimizing the chance of short-circuit phenomenon.

EVE's 18650 33v battery is your best choice because it has passed several safety certifications, such as CB, UL1642, and UN38.3. These certifications ensure its high level of safety and reliability. The increased safety standards of EVE's 18650 batteries make these an excellent solution for e-bikes, electric motorcycles, and two-wheelers.

Before we jump to the final words, here is another tip for those noticing that little V right after 33, and wondering what it means. Well, that “V” differentiates all the energy cells from power cells, which is followed by a “P”. While an energy cell is, as its name suggests, designed to deliver high energy, a power cell is to deliver high power and support fast, safe and reliable charging under complicated circumstances. Their differences set them apart for different purposes. If you are looking for batteries that are good at delivering sustained, continuous current over some time, the energy cell is ideal for applications like scooters, e-bikes, small energy storage, vacuum cleaner, etc. On the other hand, power cells are capable of delivering high current loads over a period of time at intermittent, which is an indispensable feature for use in high-rate and starter applications or power tools that generate high loads/torques, such as gardening tools and construction tools (lawn mowers, chainsaws, electric drills, and cutterbars).


The 18650 lithium-ion battery is a game changer for engineers and designers of tools and equipment. The needs and technology to keep up with future engineering marvels require more power, and the 18650 is ready to take on the challenge.

Established in 2001, EVE has been committed to the research and development of powers for the past two decades. As a global lithium battery company, we possess core technologies and solutions for consumer, power, loT, and renewable applications. So, if you are still having trouble picking the right 18650 lithium batteries, please get in touch with us, we are always happy to offer you satisfactory solutions.