Best 18650 Battery and Which to Avoid
What exactly is the 18650 battery and should you be running to get some?
Published October 18, 2018
Everything we use today seems to utilize lithium-ion batteries. You’ll find them in your smartphone, flashlights, electronics, and more. With newer technologies occurring every day, cells that were once used by manufacturers only are now available for consumer purchase. These more modern lithium cells aren’t standardized like the typical rechargeable AA battery. That’s why you need to know what the best 18650 battery is and how to avoid the ones that are fake.
In this article, we’ll discuss what a 18650 battery is, what the specifications are and how they’re different from a AA, plus the best models to buy. We’ll also briefly touch on how you can protect yourself from fake 18650 batteries, because there are plenty on the market today. By the end, you’ll be able to determine which 18650 battery will work best in your gear.
What Is a 18650 Battery?
The 18650 battery measures 18mm x 65mm. You quickly notice that its name refers to its size. The 18650 is also being hailed as a new standard for rechargeable and replaceable batteries. While they have the standard performance of a typical lithium-ion battery, their capacity is 1800mAh – 3500mAh and they feature an output of 3.7 volts. That’s what makes them ideal for laptops, cameras, and other electronics.
They feature the best performance when compared with any other rechargeable battery available to consumers. They aren’t subject to damage when charged before it’s fully discharged like nickel-cadmium cells are. With that said, 18650 batteries do degrade at a similar rate to a smartphone battery.
Specifications of a 18650 Battery
Even though they look a lot like a AA battery, they aren’t the same thing. Let’s take a look at what makes the 18650 battery different from others.
The 18650 battery features flat, thin sheets of metal to make up the cells. They’re stacked and rolled tightly; think of a jelly-roll. Between those layers, the lithium ions move one direction during charging and another while discharging. This roll gets packed into a cylinder shape made of hard steel. It features an open top and then is capped with its positive pole before being sealed.
As stated previously, the 18650 battery measures 18mm x 65mm. It’s basically the same shape as an AA battery, but slightly larger. If you were going to classify the AA battery by the same standard, it would be a 14500 because of the 14mm x 50mm size.
The shipment of 18650 batteries is more difficult than conventional batteries. That’s because they’re classified as a dangerous good due to the explosive nature when on an airplane. Customs regulations tend to be strict and the rules constantly change. IMR Batteries states on their website that shipping lithium-ion batteries is considered HAZMAT and also considered to be hazardous goods per the US Dot Shipping Regulations.
Find the Best 18650 Battery
The 18650 battery isn’t like your typical standardized cell. Between various brands, there’s varying levels of quality, amperage capacity, and continuous discharge ratings. That’s why you need the right information if you want to purchase the best 18650 battery. Here are some factors to consider when shopping for 18650 batteries.
The continuous discharge rate is one of the most important things to examine. This is measured by amps (A). You must match the battery’s CDR by the power draw of your device. If you choose the wrong 18650 battery, the cells become too hot. This heat then damages the battery and reduces its lifespan. In addition, it can cause the battery to leak, explode, and destroy your devices.
What’s good is that there is a relation between the mAh (battery capacity) and CDR. If the capacity is high, the CDR is lower. That allows the device to draw less power so it can take advantage of the higher-capacity cells. Hungry devices must have the lower-capacity cells to draw current safely.
You want a battery that lasts. In fact, it’s one of the most important things that people look for when buying a battery. You don’t want to turn on your flashlight when you need it just to find out that the batteries are dead. Look for batteries that feature a long-lasting charge and extended shelf life as well.
Voltage controls energy flow in your device. With a high voltage, the current moves faster which provides additional power. With a high voltage, however, you might face overheating. It’s also possible that the battery power drains quicker than you anticipate. Check the manual of whatever product you’re using to see what the recommended voltage is.
Most of the 18650 cells receive ratings of 3.6 or 3.7 volts. They’re pretty much the same. The complete range is 2.5 – 4.2 volts. You typically don’t want to go lower than 3 volts.
Everyone should own rechargeable batteries; there’s just no reason not to. These specialized batteries are going to wear out, so save yourself some money by grabbing a 18650 battery charger with your purchase.
There are varying types of 18650 batteries. Some have a prong while others have flat sides. That’s why you need to verify what your device needs before making the purchase. Otherwise, you might not be able to use the batteries you bought.
When you purchase a battery that doesn’t feature the right voltage for your needs, you have serious safety concerns on your hand. In addition to that, you want to make sure the casings aren’t weak. If the outer casing is compromised, it wouldn’t be safe to operate. Only purchase batteries that are fully enclosed.
With this in mind, it’s crucial to note that lithium-ion batteries become safer all the time. They are sturdier and fewer people have trouble with them.
What’s the Difference Between Protected and Unprotected 18650 Batteries?
Once you begin your shopping, you’ll notice protected and unprotected 18650 batteries. Protected cells contain an electronic circuit which is integrated into the battery design. It’s located at the end of the battery.
This circuit keeps the battery safe from excessive charging plus discharging, extreme temperatures, and short-circuiting. With this safety features, you are better protected from leaking or explosion because of the valve located inside. When the pressure rises too high, the valve disables it for protection.
Obviously, an unprotected battery doesn’t contain this circuitry. They cost less but come with the threat of trouble. If you choose to purchase unprotected cells instead, you need to take some extra care with your batteries.
It’s always best to invest the extra money and buy protected 18650 batteries, just to be safe.
Flat Top vs. Button Top
The 18650 battery comes with two variations as far as the size goes. There’s a flat top design and button top. These terms relate to the contacts on the battery, most importantly, the positive connection. With a button top design, there’s a small protrusion. A flat top doesn’t have this and remains flush.
It might not seem like it should matter, but that small size difference is crucial. It makes the difference whether a battery fits or not. If you aren’t sure which one to purchase, take a look at the batteries installed in the device or check your owner’s manual. If your product is spring-loaded, it shouldn’t make a difference which one you purchase.
Top 10 Best 18650 Batteries
We’ve found the top ten 18650 batteries for your consideration. We’ve thoroughly reviewed each one to share with you the pros and cons of the different choices.
1. ATK 3.7v 18650 Battery
If you want a battery which doesn’t supply a ton of power for your smaller devices, these might work great for you. They operate at a lower current than most, which makes them one of the weaker options, but they are long-lasting and safe.
Because of the lower power output, there’s virtually no chance of overheating. Just to be safe, the manufacturer also built in an auto-disconnect feature that shuts off the battery if it experiences a power surge.
The company claims this 18650 battery has a five-year storage life plus more than 500 complete charge cycles. This means you could fully charge it every day for almost two years without a problem. That’s pretty impressive considering the price.
2. On the Way2Pcs 18650 3.7V Rechargeable Lithium Battery with Battery Charger
If you want to purchase the best 18650 batteries, but don’t have a lot of money to spend, this budget-friendly option might be right for you. Not only does it come with two batteries, but the 18650 battery charger is also included.
You can utilize the charger for on-the-go power as well. It folds up easily when not in use so you can take it anywhere with you. These batteries handle 500 charges and will hold an 85% charge for more than a year.
While they do offer plenty of power and hold their capacity well, they appear to be slightly thin in relation to the material. This makes them prone to damage and also susceptible to overheating.
The lack of protective outer insulation should be a concern to anyone that regards safety as an important factor.
3. 2 Panasonic NCR18650B Protected Button Top Batteries
These are priced a high higher than typical batteries but come from the Panasonic brand name. The Panasonic name is worth the extra cost because it offers peace of mind. You know they are designed to be safe and charge quickly.
This button top design also comes with built-in heat insulation. They’ve also included a strong electrical resistance which makes them nearly immune to overheating. Not only that, but the Panasonic brand ensures that they are long-lasting. This means you won’t need to replace them often like you would with cheap batteries.
Just make sure you verify that your device accepts the longer top these come with. Otherwise, they might not fit at all. If they will work, this is one of the largest capacity, safest, and durable options on the market right now.
4. Solaray High Capacity 18650 Rechargeable Lithium Batteries
Another option as the best 18650 battery is this pack from Solaray. They were designed to work in the company’s flashlight, but you could use them in any compatible device. They offer PCB protection and have built-in overcharge protection.
The premium high storage capacity is rated for over 500 charges which allow for a superior lifespan. Users have been genuinely pleased with the results and felt the quality was well worth the money.
5. Samsung INR18650-30Q High Drain 4-Pack Battery
If you need a high-quality flat-top 18650 battery, you might as well purchase this four-pack because they’re backed by Samsung, a leader in electronics. This lithium-ion battery drops to 60% capacity after 250 full charging and discharging cycles. If you store them in a proper case located in a cool, dry place, you’ll find that they supply more power for longer.
When you purchase these from a supplier other than Amazon, you’ll want to verify the weight to avoid fakes. They’ve been found as a common brand for counterfeiters to attempt to knock off. That’s why it’s imperative that you always purchase from a reputable source.
6. EBL 18650 2-Pack Batteries and Battery Charger
This pack of 18650 batteries is another budget-friendly option. On top of that, it comes with a universal battery charger. With this charger, you have access to MCU control technology to maintain the proper voltage and current at all times.
The low self-discharge technology allows these batteries to hold 75% of capacity for a year while in storage. In addition, the longer vitality allows it to last 1,000 cycles while retaining the electric charge, even at high temperatures.
The battery charger features easy-to-read lights. If the light is red, the system is charging. If the light is green, it means the batteries are fully charged.
7. Samsung High Drain INR18650-25R Rechargeable Flat Top Batteries
This set of Samsung 18650 batteries are priced slightly lower than the ones we reviewed previously. These are an ideal option if you need the flat-top design. They are rated lower than the other Samsung batteries, but great for lower-powered applications.
After 250 full charges and discharges, the capacity drops to 60%. Depending on who you purchase these from, you might also find a 100% money-back guarantee, which offers some additional peace of mind against fraudulent batteries.
8. HeCloud 6000mAh 18650 Rechargeable Batteries with 2x Dual Charger
Avoid the hassle of having to purchase your 18650 batteries and your charger separately. With this package, you get both at the same time, and for a decent price. The batteries are rechargeable up to 1800 times. In addition, this set of batteries is environmentally friendly.
The only negative reviews from this line of batteries seem to be related to fake batteries. This is the reason you must purchase them from a reputable seller.
9. 4 INR18650-25R 18650 Samsung Rechargeable Flat Top Batteries + Extras
While these batteries were previously reviewed, this package comes with some extra bonuses which add value. This flat top design was manufactured for GMT using OEM Samsung cells. Included in this package deal are GMT cases for easy travel and storage.
The majority of reviewers were happy with the performance from this set of batteries. What made the difference in this over the other option were the travel cases. Considering the small amount extra you need to pay, it seems well worth it.
10. 2x Imren IMR 18650 Flat Top High Drain Batteries
These 18650 batteries are great for any electronic device which requires this size. They feature the flat-top design. In addition, the capacity does drop to 60%, but only after the first 250 charges and discharges. That’s almost a complete year if you charge them daily.
There’s a plastic storage case included with the purchase, which makes them easier to transport and store. Considering batteries last longer when properly stored, this means that the life should be prolonged as a result of the additional case. In our opinion, that’s worth paying a few more bucks for.
Avoiding Fake 18650 Batteries
Just like any product you purchase, you need to be wary of fakes. Vendors, especially overseas, tend to buy cheap cells and then rewrap them to appear like name brands. This happens commonly on eBay and Amazon.
Not only do you waste your money when you purchase fake batteries, but they are dangerous. The only way to determine that a battery is fake is to examine the weight. Find out the weight of the branded battery you’re purchasing and then measure it when they arrive. They should match the manufacturer specification or they are fake.
Don’t Forget that Charger!
Since you’ll be charging a 18650 battery, it makes sense that you also invest in the best battery charger. We highly recommend the Nitecore i2 Intellicharge Charger. This system recharges lithium, NiCd, and NiMH batteries. It can charge two batteries simultaneously and features three color LED displays to show the progress.
When you purchase your 18650 battery with a charger, you kill two birds with one stone. You’ll have the batteries you need, and then you’ll also be able to charge them for future use.
Now that you know what you’re looking for in the best 18650 battery, it shouldn’t be hard to make your purchase. Then, you can charge them up and power up your equipment! It doesn’t get much easier than that.
Make sure you purchase from a reputable seller and choose the specifications that work best for your application. This keeps you safe and helps your batteries last the longest. In addition, if you notice anything unusual with your 18650 batteries, make sure you stop using them immediately. Otherwise, you could risk your safety, and it’s just not worth a few bucks.
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