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How long do 18650 batteries last?

How long do 18650 batteries last?

18650 batteries are used in high-power electronics, and while they require around three hours to charge, the duration expected to last cannot be specified precisely. The reason for this is that a variety of factors influence how long these batteries last. In this article, we will discuss it from two perspectives: life cycle and single charge longevity. So let us dive in.

Single charge duration 

Numerous factors influence how long it takes for a battery to discharge from full to zero, including capacity, device power consumption, frequency of use, temperature, and so on. If you’re looking for an estimate, it can range from 8 hours for low-intensity use to 3 hours for heavy use. Cordless tools and certain flashlights are examples of equipment that consume a lot of power.

Please note that this is an estimation and the actual duration depends heavily on the capacity of the particular battery and the power consumption of the device it’s used in. An exact time cannot be given without this specific information.

18650 battery life cycle

All batteries have a limited life cycle. If you’re unfamiliar with the term “life cycle,” it refers to the number of times a battery is fully charged and entirely discharged until it can only supply 80% or less of its original capacity. 18650 batteries are constructed of lithium-ion and have a life cycle of 300 to 500 cycles. Moreover, If the maximum discharge current limit (A) is exceeded, the cycle life can be reduced to as few as 50 cycles. In case you are a battery hog, have no fear since proper usage can extend the battery life cycle. The exact number of cycles can vary quite a bit, depending on how the battery is used and charged. Some high-quality 18650 batteries might exceed the 500-cycle mark when treated optimally.

Tips for making 18650 batteries last longer

Charging habits

Whether it’s a phone battery or a cylindrical battery, when it comes to lithium-ion batteries, you must adhere to a set of rules to guarantee that you may use them happily for an extended period of time. These guidelines include proper charging and discharging practices. The charging habit involves not entirely charging and draining the battery, in addition to adhering to a range of other guidelines. 

  • The guideline advises that batteries should not be charged over 80% and should not be discharged below 20% since this can decrease their life and cause them to wear out more quickly. With this method, you will use the battery for a shorter time and charge it more frequently, but you will get more than 300 to 500 life cycles out of it. Furthermore, the idea behind this approach is that it gives the battery room to breathe, preventing any buildup of pressure. While this approach can potentially prolong the overall lifespan of a battery, it might not always be practical in all usage scenarios.
  • Charge the battery before using it. If you are not going to use the battery for a while, avoid charging and storing it because this puts the battery under stress. Besides, the likelihood of any dangers associated with storing batteries decreases.


While using the rapid charging technology is pleasant, it has the potential to reduce battery life. This technology is capable of charging at a rate of up to 4A, whereas standard chargers run at a rate of 1.0A-1.5A. Just as rapidly depleting the battery degrades its life, rapid charging also negatively affects battery life.  Additionally, rapid charging produces heat, which is terrible for the battery. Also, after charging, the battery should be cooled to room temperature before use.

It’s also worth noting that many modern devices and chargers have intelligent systems to manage heat and charging speed to minimize these downsides.

Make sure that the charger features a set of safe charge protection such as overcharging. Ascertain that the charger includes a set of charge safety features, such as overcharging protection. This safeguard is designed to prevent charging when the battery is near to being fully charged; it significantly contributes to the battery’s lifespan extension.


The temperature has a significant effect on the performance of a battery. When the environment is extremely cold or extremely hot, the battery cannot operate optimally. Heat can accelerate the degradation of nearly every battery component and cause safety risks, such as fire or explosions. The ideal environment temperature for optimal performance and longevity is room temperature (around 60°F to 77°F or 20°C to 25°C).

How long do 18650 batteries take to charge?

The time required to charge 18650 batteries is dependent on the battery’s capacity, the charger, and a few other factors. Charging a 18650 battery takes around 4 hours with a standard charger, but just 3 hours or less with a charger equipped with rapid-charge technology.

In detail, batteries with a larger capacity (mAh) have long, thin electrodes, while batteries with a lower capacity (mAh) have shorter, thicker electrodes. Because low-capacity cells have a lower internal resistance, they can be charged and discharged more quickly.

Also, the ambient temperature plays a significant role. It is recommended to charge the battery at temperatures greater than 0°C and less than 45°C. Not only will the battery charge normally at this temperature range, but it is also safe for the battery, as the battery can catch fire or explode at higher temperatures.

How often should you change your 18650 batteries?

18650 lithium batteries have a life expectancy of 300 to 500 cycles. As a result, you can replace them when they reach the end of their life cycle. You’ll notice the battery getting close to the end of its life cycle when it starts to hold less and less charge. This usually happens in time and initially, it will not be that noticeable, however after a certain number of charge/discharge cycles you can see the battery not being able to hold as much charge as it used to. 

Can you overcharge 18650 batteries?

Generally speaking, manufacturers incorporate integrated circuits that provide multi-charging safety features like overcharge protection. When the battery is close to being fully charged, this integrated circuit interrupts the charging process. However, it is wise to keep an eye on the battery whenever you are charging it because batteries are complex, and anything is possible. 

It’s worth mentioning that 18650 batteries come in two types: protected and unprotected. The protected 18650 batteries feature the integrated circuit discussed previously, while the unprotected ones do not. Due to the absence of this technology, unprotected batteries are less expensive, but there is a risk of overcharging and other battery-related threats. As a result, it is recommended that you purchase protected 18650 batteries. 


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