Most popular
Samsung 40T Li-Ion
samsung 21700 battery
10/10 icon-question
  • Lithium-ion
  • 4000 mah capacity
  • 35 amp continuous discharge

Samsung is well known for its excellent products, including its batteries. These lithium-ion batteries provide high capacity and discharg...

BestFire 21700 Battery
BestFire 21700 battery
  • 4000 mah capacity
  • Li-HP
  • 60 Amp continuous discharge current
Imren 21700
Imren 21700 Battery
  • 4000 mah capacity
  • 35 amp continuous discharge rate
  • 3.6 to 3.6 nominal voltage

Here are 6 Best 21700 Batteries

#1 Samsung 40T Li-Ion

The Best 21700?

10/10 icon-question Review score

Samsung is well known for its excellent products, including its batteries. These lithium-ion batteries provide high capacity and discharging/drain capabilities, meaning absolute 4000 mah capacity and constant and accurate 35 amp discharge. Moreover, it can do all these things without reaching excessive temperatures.


  • Easy-to-use
  • Well protected
  • Long life


  • Long charging

#2 BestFire 21700 Battery

Affordable With High Capacity

9.5/10 icon-question Review score

These high-capacity batteries have 4000 mah. And its charge very quickly compared to similar cells. Additionally, they are affordably priced at $7.99 per cell. So bestFire batteries are perfect for vapers looking for mid-range price batteries. Cause it can provide several hours of steady vaping time and less waiting between recharging.

#3 Imren 21700

Two-Pack Batteries

9/10 icon-question Review score

The Imren 21700 is a monster of a battery. It provides a high amount of power and steady output throughout the day, even when the vape is set to high wattage. So again, here is another perfect example of a battery that is ideal for high-wattage box mods and rebuildable atomizers. Better yet, they come in packs of two for $22.

#4 Imalent 21700

High-Capacity Battery

8.5/10 icon-question Review score

This 21700 Li-ion battery may be expensive compared to others on this list, but the price is worth it. In addition, they last a long time and provide lots of vaping between recharging. Those attributes are not surprising, considering they are 4000 mah batteries.

These batteries stand out because FastTech covers them with a solid warranty. In addition, they can be returned for a refund within 45 days or a replacement within six months.

#5 Basen IMR 21700

A Genuine 21700 with Thousands of Charge Cycles

8.5/10 icon-question Review score

The Basen IMR 21700 is a long-lasting battery with a 4000mAh internal capacity and a nominal voltage rate of 3.7V. The cell is fully wrapped and protected and comes with a flat-top design. In addition, a small regulator chip on the bottom of the device offers several layers of protection, like overcharge and overheating protection. The cells have a continuous discharge rate of 25A, but the highest it can go is 30A.

Reasons to Get This:

  • You want a safe and reliable battery
  • You want a battery with many charging cycles
  • You want a battery that is wrapped and protected

Kit Contents

  • 1 x Basen IMR 21700 (2-pack)


  • Accurately rated (capacity and output)
  • Lots of charge cycles
  • Holds a charge for a long time
  • Perfect for regulated mods


  • Not suitable for mech mods

#6 Vapcell INR 21700

A Reliable Battery with Safety Features

8/10 icon-question Review score

The Vapcell INR 21700 is a rechargeable lithium-ion battery with a well-wrapped exterior and a large internal capacity. The Vapecell battery has a 3000mAh capacity and a nominal output of 3.7V. The ratings on the battery’s wrapping are accurate. The cell has been measured to output up to 25A, but it can reach a maximum discharge rate of 35A.

Reasons to Get This:

  • You want a reliable battery
  • You have a lot of 21700 devices
  • You want a battery from a reliable brand

Kit Contents

  • 1 x Vapcell INR 21700


  • Holds a charge for a long time
  • Perfect for regulated mods
  • Wrapped and protected
  • Thousands of recharge cycles


  • The wrap breaks too easily

Battery Capacity Price Rating
Samsung 40T Li-Ion 4000 mah $8.99 10
BestFire 21700 Battery 4000 mah $7.99 9.5
Imren 21700 Battery 4000mAh $22.00 9
Imalent 21700 Battery 4000mAh $18.84 8.5
Basen IMR 21700 4000mAh $22.02 8.5
Vapcell INR 21700 3000mAh $12.36 8

What is a 21700 battery?

A 21700 battery is defined as a cell that measures 21mm in diameter and 71mm in length. This cell is one of the largest lithium-ion batteries on the market today. The cell can be found not only in high-wattage vaping devices but in everything from e-bikes and scooters to laptops, flashlights, and many different electronic devices.

The nominal voltage range of most 21700 batteries runs between 3.2V and 3.7V. The capacities for these much-larger batteries still run anywhere from 3000mAh to 5000mAh. They can vary depending on the brand and manufacturer. 21700 batteries also come with various features like silicone chips and flat-top designs for added protection against shorts, over-charging and overheating.

What are the Differences Between All Vape Batteries?

The main types of vape batteries are:

The main differences between all these cells are their size and capacity. The different numbers represent each cell’s measurements (18mm x 65mm, 26mm x 65mm, etc.). And the cell’s size correlates to its capacity, meaning the bigger the cell, the more power it can hold and output. 18650 batteries were, and still are, the most popular type of battery for vaping devices. But the 20700s and 21700s are also starting to make inroads since they can hold much power and last longer.

What Are the Advantages of 21700 Batteries?

The advantage of 21700 batteries vs. the 18650 battery is that they last longer than 18650s or integrated batteries when used at high wattages. Another advantage over integrated batteries is that they can be replaced when no longer able to hold a charge. Integrated batteries cannot be replaced.

Which Are the Best 21700 Batteries for Vaping?

Deciding on the best 21700 batteries is difficult because “best” is highly subjective. Everyone is looking for something different. Some people want high-end batteries that can work for over a day on high wattages. Others are fine with using lower-priced batteries because they are on a budget or do not want to spend much money on cells when they plan on vaping on low to medium wattage levels.
All these batteries were excellent and will benefit vapers of all types.

How We Picked the Best 21700 Batteries

The Imren 21700 may be the most expensive battery. But it outranks the other batteries for several reasons.

First, it is not all that expensive in the long run. The battery can last up to 800 cycles, which is more than many other batteries can offer. Cheap batteries might look inexpensive when looking at the price tag alone. But the cost increases if they are suitable for only a few cycles.

Another reason why we picked it is that it is powerful. Again, it is not as powerful as the Samsung 40T, but it can handle up to 90 watts and offers good battery life.

Frequently Asked Questions About the Best 21700 Batteries

What Is the Most Powerful and Best 21700 Vape Battery?

It is difficult to say which is the most powerful because they all have the same capacity. But the most dependable is probably Samsung’s. They perform at a high level without overheating and last a long time.

How Long Should a 21700 Battery Last?

It is difficult to say because every battery is different. But over time, batteries oxidize and degrade, so they cannot be changed infinitely. However, 21700s rank among the longest-lasting on the market. They can be charged up to 2,000 times, depending on the battery.

How Long Does It Take to Charge a 21700 Battery?

The average charge time is four hours, depending on the battery and the 21700 battery charger used.

Each battery and charger is different. To figure out how long it takes for a battery to charge, determine the reserve capacity of the battery, and multiply it by 0.6.

How Do You Change 21700 Battery Wraps?

Remove the old wrap and then slide on the new wrap. Then, use a heat gun or hair dryer to secure the new wrap.

How Low Can You Build With a 21700 Battery?

To determine how low you can build, use Ohm’s Law for mechanical mods and Watt’s Law for regulated mods. Plug the values into the formulas for these laws, and you will get an answer.

What Is the C Rating of a 21700 Battery?

Each cell will have a different C rating. Use the formula C Rate(mah/1,000) = Continuous Discharge Amperage to determine the rating.

What Should Vape Coil Be Used for the Best 21700 Batteries?

The vape coil depends on the preference of the user. Read the directions for the mod to determine which materials work best for your mod.

How Can I Spot a 30T 21700 Battery?

30T 21700 batteries are widespread. First, look at the product description on the package or online to determine whether they are 30T.

How to Spot a Fake Samsung 21700 Battery?

To spot a fake battery, check the label, contact, and overall appearance of the battery. Buyers who are worried about getting duped should buy their products from a physical store.

How Do I Know If My 21700 Battery Cycle Is Done?

Eventually, the battery life will decrease to such an extent that charging it is no longer feasible. When this happens, replace the battery.

Final Thoughts about the 21700 Battery

Lithium-ion 21700 batteries are worth purchasing over cells like the 18650. There are a lot of good brands available, and using them will allow for more vaping time than one would get from a 18650. The best ones to get are Golisi and Samsung in terms of economy and performance. These batteries are expensive, but there are cheaper options if the shopper looks hard enough. Cells like the MXJO are some of the most inexpensive batteries on the market.

Please give us your input if you are a fan of what we think are the best 21700 batteries. Also, if any batteries or chargers out there are high performers and we neglected to mention them, please talk about them in the commenting section.

Published: March 27, 2020 Updated: September 28, 2022

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