Getting the best 18650 battery is a pretty complicated process and especially if you are totally new to the Lithium-ion 18650 world.
First of all, best for what? As you will see, there are many different brands and their batteries offer a lot of variables. Getting the best one will depend on your needs and your budget.
But let’s not get ahead of ourselves in here.
Before we start talking about the battery brands you must know a lot of details when it comes to the 18650 batteries.
These batteries have a serious potential for danger, they can burst into flames, explode, drastically lose their capacity if not handled properly, they are sold by hundreds of brands and only a few are genuine, meaning that they are overly faked on the market, they have size differences, a lot of voltage/amps/capacity differences that you must know about, they have different safety levels and designs…
You get the picture. This is not simple stuff but it is not very complex either.
First things first.
You do not want to buy a fake junk 18650 battery. You don’t want your battery to explode on you or to get something that has extremely low mAh capacity. You don’t want to be ripped off and endangered in the process.
That is why you really need to read the buying guide first and only then proceed to the battery reviews.
This is not a joke.
Only skip to the batteries themselves if you are 100% sure that you understand Li-ion 18650 cells!
Another thing you must understand is that I am providing this information in good faith and based on the vast research I have done. I am not responsible for your actions with batteries, your buying decisions and how the batteries perform on you. I will do my best to help you learn about the 18650 batteries and help you pick the right brand but ultimately all the responsibility is yours, to handle them well, to be educated about them and to trust the brand.
This all sounds serious? Well if you do things properly and get the batteries from the trusted brands and from a trusted place you really shouldn’t have any problems as long as you handle the batteries properly.
Another reassuring thing right off the bat is the fact that if you are buying an 18650 battery for a flashlight or something low powered you don’t need to worry about anything bad happening as long as you get the proper battery for that use and from a proper brand. This will be discussed further in the article.
But if you will be doing any DIY 18650 battery work or if you will be powering demanding devices it is really important to know a lot of things prior to getting the battery itself.
Now let’s see the details.
18650 Battery Guide – Everything You Should Know
You should first read this buying guide and then check out the suggested batteries. That way you will know which is the best 18650 battery for your needs.
I have done vast research to compile this information in one place but one can never be too sure so you should continually educate yourself on lithium-ion batteries if you are a total newbie. It takes some time for all of this information to click in the place and for you to digest it.
Let’s first start with the scary stuff. The fake batteries that are flooding the market.
How to spot and evade fake 18650 batteries
This is a short summary. If I wrote everything there is about it I would need a dedicated article for that.
Well first of all, the big tell-tale sign is that the battery has exaggerated capacity.
Currently, at the time of this writing, there are no real lithium-ion 18650 batteries on the market that exceed the 3600mAh capacity and especially if coupled with a high CDR rating. What is CDR rating will be covered further in the article.
This doesn’t stop some evil people to prey on uninformed buyers. There are brands out there that claim that their batteries hold over 9000mAh capacity.
That is literally impossible. It is as if these people are telling you that the sky is green. Absolute cheats and it amazes me that they get away with it. These fakes usually hold less than 800mAh of capacity.
The worst part is that they are not just going to rip you off financially. There is a real danger of their batteries bursting into flames.
Do you honestly think that such people would care to make a safe battery? No. Far from it.
Another tell-tale sign is the battery weight.
A battery of a real capacity like 1500-3500mAh should weight anywhere from 40-55 grams.
If a battery claims to be 3500mAh for an example but weights about 20-30 grams it is most likely fake.
These are the basics of spotting fakes. Now we need to move on further.
What are the top 18650 battery brands then?
Well, I am glad you asked.
First thing you need to know is that there are two types of branded 18650 batteries.
OEM and rewrap brands. Rewraps will be explained in a second.
OEM, aka, Original Equipment Manufacturer are the brands that are the source of the quality batteries on the marketplace. They are very often bought in bulk and then rebranded and sold further to consumers or sold in their original form (these are the ones I will talk about further below).
In the case of 18650 batteries and many other li-ion cells, the OEM brands are available to you as a consumer to buy them per single cell basis. Only you can’t buy them from the manufacturer but from a reseller.
That is okay. Because while they are being resold, they are not being rebranded. They are also fairly cheap when compared to the rebranded cells.
Your average OEM 18650 battery will look like a cylindrical cell in a single color plastic wrapping without any fancy branding on it.
The most trusted OEM brands that literally everyone from the battery community would trust are:
Those brands manufacture their batteries mostly in Japan and Korea. Their production quality is excellent as they have been in this game for a long time. This allowed them to perfect their craft and batteries from these brands are generally speaking, safe, have as advertised capacity or very near to it and don’t easily lose their capacity.
Now what was that about the rewraps that I mentioned?
Oh yeah there are those as well.
The rewrap is a popular term in the battery community. It means that the battery was bought from one of the OEM brands and rebranded and sold by another brand. Those batteries are then rewrapped in a plastic wrapper that has that other brand name and design.
They don’t just offer a fancier design. Many times these brands offer superior quality control by ditching any OEM battery that has less capacity than advertised, they improve the safety of batteries by adding certain protections (more on this later), these batteries can have a button top (again more on this later in the article), they can be charged via USB and etc.
They add on value but more often than not these batteries are more expensive than they are worth. And unless you really need a special feature that a rewrap could offer, you are going to get a better price per charge on the OEM battery.
Now you are well on your way to becoming a battery master yourself.
But not just yet. There are still some serious stuff to discuss.
Battery capacity, voltage and a few very important things
Ready to get some juicy stuff? Get it? Juicy as battery juice? The mAh capacity.. I would show myself out but I still have to share my knowledge so bear with me!
Now we will dissect some of the science stuff.
I will keep it simple, plain, conversational and entertaining (hopefully). I don’t want you to lose focus here as these are the important things that will help you decide which battery to buy.
The battery capacity – mAh
The capacity of any battery is measured in milliampere hours, the mAh. It can also be stated in ampere hours or Ah.
Short version: The bigger the mAh number the more charge the battery has. If you don’t need a long version, just proceed further.
Longer version: The amount of charge that gets transferred in an hour is designated as a mAh. For example, if your battery says that it has 3000mAh capacity. That means that your battery can transfer 3000 milliamperes in one hour. So if your load draws that much charge, your battery will deplete in one hour.
On another hand, if your device pulls 100 milliamperes per hour from your battery, the battery will last 30 hours if it has a 3000mAh capacity.
Easy stuff right?
But there has to be a catch, right?
Yes.. there is a catch. It is called CDR or Continuous discharge rating. This will be covered in more detail below.
CDR – Continuous discharge rating
This is it. The most important part.
If you get this one right, coupled with the right brand and you handle your battery properly, you don’t have to worry about your battery dying sooner than its time, blowing up, or not being able to supply your device with power.
CDR or otherwise called the current rating is one of the most important factors when buying a 18650 or any other li-ion cell.
This rating specifies the maximum current that the battery can be discharged at continuously. The manufacturer will provide this information.
The current rating is specified in Amps. So a battery that is rated for 10A means that your device shouldn’t discharge the battery at a higher current. This is why you need to know how much current your device requires prior to getting the battery.
If you use a battery that has a lower current rating than what the device needs, your battery will overheat which could end either tragically (not likely if you don’t overdo it and the battery is from a good brand) or it will influence your battery to lose its rated capacity much sooner and generally cause your battery to die.
Basically, don’t overload your batteries and all will be well.
But how is this a catch when it comes to the capacity?
Ah, a keen eye, this one has.. Thanks for reminding me.
Yeah, the catch is the fact that the more capacity the battery has the lower the CDR will be. Meaning that it is not simple to manufacture a battery with let’s say 3000mAh capacity and for that battery to be able to handle a 30A load.
Not simple but not impossible either.
Some of the OEM brands have their battery lines that have a very good capacity to current rating ratio. Those are usually very favored batteries in the market place. You will see those reviewed in the reviews section.
// Totally a pro tip for you:
It is also completely fine to buy a low current rating battery with a high capacity if you don’t need it to handle more load than it is capable. Don’t buy highly rated batteries like 30A if you need 10A for your device. That way you can get more charge for less money.
Another (conflicting) pro tip:
However, if you are able to spend a dollar or two more per cell, it is wise to get a higher current rated battery because it will allow you to stay on the safe side. This is especially important if you will be doing any DIY battery stuff and you are a beginner.
Ah, the voltage.. As if things couldn’t get more complex.
Bear with me just a little bit more. This is the last part that might be more difficult for beginners with li-ion cells.
In theory, you could skip this but it is probably best to read it if you want to know more about your cells and how to choose the best 18650 battery that can actually sustain itself through the use cycle. Whatever that you plan on doing with the 18650 batteries, you will do better if you know how the voltage works and influences them.
First of all the nominal voltage of a 18650 cell is the 3.6v. This is the average voltage during a discharge cycle.
The voltage of 3.6v is not constant. It changes. The more charge there is in the cell the higher the voltage.
The total voltage range for most 18650 batteries is between 2.5 volts and 4.2 volts.
The fully charged cell will sit around 4.2 volts. Once completely depleted it will drop to 2.5v.
You should never completely deplete your cell. It is wise to stay above 3v prior to charging it again.
If your device requires a certain voltage let’s say 3.6v which is normal as it is the average voltage. The device will be able to use the battery charge from 4.2v (fully charged) to somewhere around 3.6v. Then the battery will no longer be able to power your device or it will not do so efficiently.
If your device can continue working even below 3v, your battery will deplete completely. Not good for the health of the battery. That is why some rewrap brands are a good choice because they have protection in place to prevent this from happening.
But what happens if the battery drops the voltage below 3.6v way too fast?
Then you will experience a sag in power and your device may not be able to work.
The best 18650 batteries are known as hard hitters. This is what some people mean when they say that a battery is hitting harder. Such batteries are able to maintain their rated voltage of 3.6-3.7v much longer into the discharge cycle.
So in a nutshell, you also need a battery that can sustain itself for longer. Capacity and good CDR is not enough.
Phew. We are finally done with the science stuff. Now let’s proceed with much more simple stuff.
As I said earlier a lot of battery brands that source their batteries from OEM brands add value to the batteries and resell them for a bigger price.
One of the things they do is add battery protection that is in a form of a PCB protection board. This protects the battery from over-charging, over-discharging, short-circuiting and a few other things depending on the brand.
You can also find OEM batteries with a PCB but they are still manipulated by third parties. Someone else added that PCB even if it is not a full-on rewrap with a dedicated brand name.
Batteries that use the PCB protection are the best 18650 for flashlight. Not really for high draining devices. Why?
Because devices that can work with low voltage like LED lights or doorbells or something like that will drain the battery below the 3v. That is why PCB protection is there. To cut off the power before the battery depletes too much. If your battery regularly depletes over the 3v limit it will die sooner.
The PCB protection board is literally like a small motherboard with a few microchips on it in a circular shape and it is added on to the bare battery cell. That is why the protected cells like these are a bit longer than the regular 18650 battery.
However, most devices will not have a problem with the size difference as it is just a few millimeters of difference.
Finally, the PCB protected cells are not to be used with high drain devices as the PCB limits the current rating of the battery to low numbers like 6A. If you need a 15A or 30A battery you won’t be able to use a PCB protected cell.
Flat top vs Button top
Flat top is literally it. Flat battery at its top, the positive end.
The button top battery looks similar to the AA household battery because it has a button protrusion at its positive end.
This is also added by a third party on the OEM batteries. Either a full rebrand or a OEM battery with a third party manufacturer that adds it.
Now read the following carefully:
Not all button top batteries have PCB protection but some of them do. Not ALL. It is quite common for a button top battery to also have a PCB protection but there are unprotected cells as well.
If your battery has a button top, again it will be a bit longer than a standard 18650. If it has both the PCB and button top it will be even longer. Again, this is usually not an issue. Although some devices may not be able to fit the batteries properly.
You should know what your device needs. Flat top or button top.
Best 18650 Battery Reviews:
Finally we are here.. after all this trouble.
Ready to see what I personally believe are the best 18650 batteries for various needs?
I will write about the best for flashlights, for high draining devices that require high CDR like vape devices, low CDR batteries with high capacity and etc. Again, it is up to you to make a decision to get the batteries, to use them properly and to trust the brand.
I will be listing batteries based on their quality. First I will list a few rebranded OEMs. While they are expensive and most likely not a value choice, they do offer superior quality in their own fields. After those, we will see the OEM quality choices that are much more likely to work for you and your wallet.
So, here we go.
1. Best 18650 battery for flashlight – Nitecore NL1835HP Battery
Nitecore is a brand that is known for its high-quality flashlights, battery chargers and in the third-place batteries. That is because their batteries are so expensive.
Again, while expensive, they provide a lot of value, just not enough for everyone to be using them. You should get the 18650 for flashlight from Nitecore only if you are ready to pay more in order to get a not proportionally justified value. You do get more value, however, just at a much higher price than I would like to.
The best value for a flashlight is the Samsung 30Q which will be reviewed soon below.
They are a PCB protected, button top battery that has a really high capacity of 3500mAh. The real capacity. I never experienced problems with Nitecore and I really respect their brand.
Their batteries are rated for 8A of load and that is not going to be of any issue when powering the strongest of flashlights. The PCB protection will cut off power in order to save your battery from overly discharging so that you can have peace of mind and not worry when is the battery nearing its end.
They are very safe to use with multiple protections in place.
2. Fenix 18650 Rechargeable Batteries
Another excellent choice for flashlight 18650 batteries is from the Fenix brand. They are well known as some of the finest in the flashlight industry and they have a well-known battery line. They are also overly expensive but worth it if you don’t mind paying the top dollar.
Their cells will bring you the highest capacity as they span from 2600mAh to 3500mAh capacity, coupled with the high capacity retention in the long run.
They can be recharged up to 500 times and they won’t lose more than 25% of their original capacity.
They are built with multiple safety mechanisms and with a PCB board. An excellent choice for flashlights if you need a high reliability in the long run. And you are willing to pay the top dollar.
3. Sony Murata VTC5D
This is probably the best 18650 battery from the OEM manufacturers. Sony really made a great deal here.
You get the 2800mAh capacity coupled with the CDR of 25A. That is perfect for highly demanding devices, vape mods or any DIY builds that need a big safety factor. But you also get a very big capacity as 2800mAh is good enough to run even the most power hungry devices for a longer time.
It is difficult to make a battery that has both, high CDR and big capacity as stated above in the article. This one has best of both worlds.
Additionally, it is a very good cell voltage wise. It minimizes the voltage sag that you can experience when you bring it to its discharge limits.
You can buy this cell without any PCB protection and in a flat top variant.
4. Samsung 25R 18650
This is one of the most popular and loved 18650s. This battery also has a very good ratio of current rating and the capacity.
It has a 2500mAh charge and a current rating of 20A for continuous discharge. This is one of the most used and trusted batteries ever since its release in 2014. It proved to be a valuable choice thanks to its excellent ratio of current rating and capacity.
An excellent choice for any DIY work, battery packs, very demanding lighting and flashlights, various vape mods and anything else that needs a battery that can take a good load.
It is one of those 18650 batteries that excel in a wide range of applications while being quite safe for use. They are sold flat top or with a button top added.
5. Samsung 30Q 18650
Next up is one of the best value 18650 batteries. This cell from Samsung has just a little bit smaller current rating than the previous pick, sitting at 15A of maximum continuous discharge but in turn, it provides you with up to 3000mAh charge.
To top it all off?
It is an affordable choice that ticks pretty much all of the boxes. A lot of people will not need a higher rated CDR battery than 15A. If your device doesn’t pull that much load then this battery is a great choice because it is packed with charge. This battery is also very loved by the flashlight community being one of the best 18650 battery for flashlight.
It can be bought with flat top or button top added.
6. Samsung 20S 18650 – Best for safety
This battery from Samsung has the incredible 30A CDR rating which is coupled with a decent amount of charge of 2000mAh.
The only competitor from what I can tell is the Sony Murata VTC 4 but not really because the VTC4 can handle 30A with a temperature cut off at 100C. That is why this battery from Samsung is the best option for people who want extra safety from battery overload.
Unfortunately having just 2000mAh you will be recharging them more often. The more you recharge, as with any 18650, the sooner you will reach the end of their lifespan. But that is the trade-off we have to live with. I hope one day we will have as safe battery with at least 30% more capacity.
7. Sanyo NCR18650GA
Sitting at an opposite spectrum we have this 18650 battery from Sanyo. It is designed with a maximum CDR of 10A which means that you should use it in less demanding devices.
On the flip side, it has 3450mAh of capacity. An absolute monster of a battery that will power your battery packs, flashlights, DIY projects with ease for a long time as long as you use it under the 10A discharge rate.
This battery can be bought with flat, with a button top or with a PCB protection and button top.
How to Take Care of 18650 Battery
Now that you have seen my cell recommendations we should wrap it up with some safety talk. I would urge you to continue educating yourself on the li-ion battery safety as I am not here to teach you how to do it all properly. No one can teach you that in one reading of an article. That is something that is learned continuously.
Still here are some suggestions and warnings:
- Temperature – In order to keep your Lithium ion batteries healthier you should evade exposing them to the temperatures below 0C or above 45C. That way they will last longer and lose less capacity over time.
- Use a quality charger. Don’t buy a junk charger at a dollar store. Never use a charger that continuously charges the battery and tops it off as soon as it drops below its max capacity. The best chargers are made by Nitecore and Xtar brands but there are many other too.
- Use low Amp setting for charge rate. If you use high amps like 4A to charge the batteries, you will charge them faster but in time that will reduce their capacity. Of course never use high amps if the battery can’t endure it. Even if it can, it is best to always use low amps like 0.1-2A.
- If you are going to store your batteries it is best to store them with the 3.7V of charge. That is a bit tricky because their maximum capacity charge is 4.2. But storing them at 3.7v is best for their life span. Quality chargers will have a storage mode option.
- Don’t expose batteries to too much humidity and try to avoid condensation. If you were outside with them and they got very cold, it is best to put them in a vacuum seal bag prior to entering the house. That way they will not be able to attract the water from the air and condensate it on them. Water vapor goes on anything that is cold and you should let your batteries warm up first before exposing them to the in house air.
Battery safety tips:
- Never shortcircuit your battery. Never place it in a situation where you cant know what is happening with its poles. I.e. never put them in your pocket with metal objects.
- Don’t overload them by exceeding their CDR. Just don’t do it. Get a higher CDR battery.
- Never put them near fire or high temps.
- Always use quality chargers meant for these batteries.
- Don’t solder them. You could damage the safety vents.
- NEVER PUNCTURE THEM OR APPLY PHYSICAL FORCE.
- Don’t use a battery that is leaking, is deformed, shows any weird signs like a weird smell or similar.
- Never put the battery in any liquid.
Look there are hundreds of these warnings. This is to get you started. Read and learn about the batteries if you will be building any special DIY stuff.
How To Choose The Best 18650 Battery Charger
In order to properly use your batteries you will need the best 18650 battery charger. There are hundreds of them on the marketplace and similarly to the batteries only a handful of brands are proven and trusted.
Follow the link above to read my reviews of the best choices that will serve you well and keep your batteries in tip top shape for their entire lifespan.
I haven’t covered some things even if this is a huge article there are still some things left like battery chemistries (there are more than one) but this and other things might not be of high importance to you right now.
I hope that I helped you find the best 18650 battery for your needs and purposes. Basically to recap, get a battery that has a proper current rating for your needs, enough capacity and that is in accordance to your budget. Never buy any weird cheap brands that overpromise stuff and always take proper care of the 18650 cells and you should be fine.
- A Guide to Understanding Battery Specifications by MIT Electric Vehicle Team, December 2008 at Massachusetts Institute of Technology
- Types of Lithium-ion at batteryuniversity.com
- 18650 Battery Safety at batterybro.com
- Excellent wiki on batteries in general including the li-ion on Reddit wiki.
- Lithium Ion Batteries and Their Manufacturing Challenges at National Academy of Engineering
- Tips for extending the lifetime of lithium-ion batteries at the University of Michigan
- How Does a Lithium-ion Battery Work? at Office of Energy Efficiency & Renewable Energy energy.gov