All rechargeable 18650 batteries are replaceable

The best 18650 battery and counterfeit avoidance

Lithium-ion batteries have revolutionized portable devices. They are included in everything from our smartphones and cameras to baby monitors, fitness equipment and flashlights.

As battery technology has matured, cells that were once reserved for device manufacturers have come into the hands of consumers. However, these new lithium cells aren't as standardized as the rechargeable AAs you can find in the grocery store.

You need to make sure that you are buying the right battery for the job and you need to know how to avoid counterfeit batteries.

What is the 18650 battery?

An 18650 battery is a cell that is 18 x 65 mm in size. The name only refers to the size of the lithium-ion cell, but slight deviations can also occur here. The 18650 became the new gold standard for replaceable and rechargeable batteries. Disposable Batteries: How Do They Work and Which Can I Buy? Disposable batteries are available: how do they work and which ones do you buy? How do batteries work? What is the difference between a disposable and a rechargeable device? Why do both still exist? Does it matter which type you use? We answer everything and much more. Continue reading .

They offer the performance of a lithium-ion cell, a capacity in the range from 1800 mAh to around 3500 mAh and an output voltage of 3.7 volts. They are used in a variety of devices from laptops to laser pointers and camera accessories like gimbals and sliders.

The 18650 cell offers the best performance of any rechargeable battery. They're not prone to damage from charging before they're fully discharged (as was the case with the old nickel-cadmium cells), although they degrade at about the speed of your smartphone's battery. The best smartphones for long battery life The best smartphones for long battery life A smartphone is only as good as its battery. Without electricity, it's just a nice looking stone. Most modern smartphones have decent battery life. Here is a list of the longest standing handsets. Continue reading .

You can't just buy an off-the-shelf 18650 battery when you look at capacity (measured in mAh, or mAh) alone. The right battery depends entirely on what you are using it for.

Choosing the Right Battery for the Job

The 18650 is not a standardized cell. They are not all created the same or have the same task. The most important characteristic of 18650 batteries is that Continuous discharge rate (CDR), also known as amperage.

The CDR is the rate at which current, measured in amps (A), can be drawn from the battery without it overheating. To find out which battery is right for you, you need to adapt the CDR of the battery to the current consumption associated with your device.

If you choose the wrong battery, the cells will get too hot. The battery will be damaged by heat, which will reduce its service life. Overheating can even cause the cells to explode, leak, or damage your device. How does a battery work? You might almost be forgiven for not spending time learning about the way they work. Continue reading .

Fortunately, there is a direct relationship between CDR (A) and battery capacity (mAh). The higher the capacity, the lower the CDR. This means that devices that use less power can use cells with higher capacity. Hungrier devices must use cells with a lower capacity to safely draw more power.

At the time of writing (June 2018), the maximum CDR currently achievable with an 18650 battery is 38A at 2000 mAh. Some fake manufacturers claim ratings of 40A or 35A at 3000mAh or more, but these are not to be trusted. Battery technology is constantly evolving. So expect this to change.

Protected or unprotected batteries

When purchasing 18650 batteries, you have a choice between protected and unprotected cells. Protected cells, as the name suggests, have a small electronic circuit built into the battery packaging. This is located at one end of the battery and cannot be distinguished from the cell itself.

This circuit protects the battery from dangers such as excessive charging and discharging, short circuits and extreme temperatures. This is to protect the equipment in which you use them and to prevent damage from explosion or leakage.

Many protected batteries also have a valve that permanently deactivates the cell if the pressure in the cell becomes too high. This generally happens when the batteries swell. Then they are more prone to igniting.

Unprotected batteries do not have this circuit. They are therefore cheaper and more prone to the problems that such protective measures are intended to avoid. If you choose an unprotected cell (and many of the best cells are unprotected), extra care should be taken when choosing and using your batteries.

It's very interesting how this "protected" UltraFire "4200mah" 18650 is the same length and weight less than this unprotected 2500mah LG 18650.

- Rob Johnson (@MissMelee) November 10, 2017

Pay special attention to the discharge rate (CDR) to ensure the cell is not receiving excessive power or overheating. You'll also need to keep the contacts covered, ideally in a plastic case, so the batteries aren't in your pocket or pocket. You also need to make sure that you don't leave the batteries in the charger for too long.

When in doubt, go the protected route and spend a little more.

Flat top against button top

To really show how non-standardized the 18650 battery is, there are two small size differences: flat top and button top. This relates to the contacts, especially the positive contact. Button-top batteries stick out a bit, whereas empty top-mounted batteries sit perfectly flush.

Those few millimeters can mean the difference between a battery that fits and a battery that doesn't. If in doubt, look at the batteries that came with your device, consult a manual, or contact the manufacturer. For spring loaded batteries, like flashlights, this shouldn't make much of a difference.

Here's how to avoid counterfeit 18650 batteries

As with any branded product, you have to beware of counterfeits. It is common for many vendors to buy up cheap cells, wrap them as name stamps, and sell them as real items on Amazon or eBay.

Not only is this a waste of your money, it is potentially dangerous. If you buy a battery for a high performance device and you assume that it has a sufficiently secure CDR, you could injure yourself or damage your device if the battery is found to be of a completely different rating.

Battery scammers are good at what they do. A real battery and a fake are incredibly difficult to tell apart. From the packaging to the branding to the online listings, they look like real business. The only way to tell a fake battery apart from an original battery is by weight.

Most brands have made the weight of their original batteries available somewhere. You should compare all batteries available online with the manufacturer's information. Even spelling mistakes do not indicate a fake, as a real manufacturer discovered through a Facebook update.

Dear Sir or Madam, Thank you for your attention to our VapCell batteries. We recently sent a batch of VapCell 18650 ...

Posted by VapCell on Monday 23rd Oct 2017

To check a specific cell, search the Internet for its name followed by "data sheet." The weight, capacity and maximum CDR of the battery are then listed.

The best 18650 batteries

The best batteries are usually made by Sony, Samsung, LG, and Panasonic / Sanyo. That doesn't mean all other brands are untrustworthy, but these brands provide reliable and trustworthy CDR ratings and enough information to detect counterfeits.

Sony VTC5A (data sheet)

CDR / capacity: 35A / 2600mAh

Weight: 47.1 g (variation of 1.5 g)

To buy: Sony VTC5A on IMR batteries

Sony VTC6 (data sheet)

CDR / capacity: 15A / 3000mAh

Weight: 46.5 g on average

To buy: Sony VTC6 on IMR batteries

Samsung 25R (data sheet)

CDR / capacity: 20A / 2600mAh

Weight: 43.8 g on average

To buy: Samsung 25R on Amazon

Samsung 30Q (data sheet)

CDR / capacity: 15A / 3000mAh

Weight: 45.6 g on average

To buy: Samsung 30Q on Amazon

LG HD2 (data sheet)

CDR / capacity: 25A / 2000mAh

Weight: Maximum 44 g

To buy: LG HD2 for IMR batteries

LG HG2 (data sheet)

CDR / capacity: 20A / 3000mAh

Weight: 44-45g

To buy: LG HG2 on Amazon


CDR / capacity: 38A / 2000mAh

Weight: 43.4 average

To buy: Vapcell 38A / 2000mAh on VapCellTech

Orbtronic (data sheet)

3500mAh 18650 ORBTRONIC Two protected rechargeable button top high performance Li-ion batteries 3.7 V for high performance 18650 flashlights - NOT for ecig devices 3500mAh 18650 ORBTRONIC Two protected rechargeable button top high performance Li-ion batteries 3.7 V for high performance 18650 flashlights - NOT for ecig devices Buy now on Amazon $ 34.99

CDR / capacity: 10A / 3500 mAh

Weight: 46.5 average

To buy: Orbtronic 10A / 3500mAh at Amazon

Don't forget a charger for 18650 batteries

Always choose a quality charger to avoid disappointment. We would recommend Nitecore's i2 Intellicharge charger for 18650 batteries, which can charge two cells at the same time. You can use it with 18560, AA and AAA Li-Ion and NiMH batteries.

These chargers recognize the battery status and change the voltage and the appropriate charging mode accordingly. This should help prevent damage from overcharging. However, caution should be exercised with unprotected cells.

You can also buy the Nitecore D4 with a car adapter for charging while on the go, whereby four cells can be charged at the same time.

Bundle: Nitecore D4 charger 4 Smart universal charger for Li-Ion IMR LiFePO4 26650 18650 18350 16340 RCR123 14500 Ni-Cd charger for AA-AAA-AAAA-C batteries with EASTSHINE car adapter and battery compartment bundle: Nitecore D4 charger for 4 Chargers For Li-Ion IMR LiFePO4 26650 18650 18350 16340 RCR123 14500 Ni-Cd NiCd AA AAA AAAA C batteries with EASTSHINE car adapter and battery compartment Buy now on Amazon

When buying a charger, you need to be just as careful when buying a battery to avoid counterfeiting. For best results, buy direct from the manufacturers (or their official sales points).

Which 18650 batteries are you using?

When you buy from a reputable retailer like the manufacturer's outlets on Amazon or eBay, you can be sure that you are getting what you paid for.

Don't forget to filter your Amazon reviews to make sure the feedback is real. How to Find Fake Reviews on Amazon. The only way to find a true opinion is to learn how to spot these fakes. Continue reading . You can also choose one of the other battery retailers that have a reputation for providing real, high quality batteries.

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