Fenix Battery FAQs
Helping to understand complex batteries.
How big are the Fenix 14500 batteries?
The dimensions of the ARB-L14 USB 14500 battery (ARB-L14-1600U) are 14.5mm x 50mm (.57" x 1.9").
How big are the Fenix 16340 batteries?
The size of the USB rechargeable ARB-L16 "U" battery, the ARB-L16-700U, is 16mm x 34mm (.6" x 1.3")The size of the USB rechargeable ARB-L16 "U Plus" battery, the ARB-L16-700UP, is 16.8mm x 35.5mm (.66" x 1.4")
How big are the Fenix 18650 batteries?
The dimensions of the standard ARB-L18 series 18650 batteries (e.g. ARB-L18-2600, ARB-L18-3500) are 18.6mm x 69mm (.7" x 2.7"). The dimensions of the USB rechargeable ARB-L18 "U" series 18650 batteries (e.g. ARB-L18-2600U, ARB-L18-3500U) are 18.6mm x
How big are the Fenix 21700 batteries?
The dimensions of the Fenix ARB-L21 series 21700 battery are 76mm x 21.5mm (.85" x 2.99"). It's a powerful, protected cell compatible with many current Fenix flashlights and headlamps.
How big are the Fenix 26650 batteries
The dimensions of the Fenix ARB-L4-4800 26650 battery are 26.5mm x 70.5mm (1.05" x 2.78"). Note: Fenix has phased out the 26650 format, this and other 26650 batteries are discontinued, and no current Fenix products use this battery size. This informa
How long does it take to charge a Fenix battery in a Fenix charger?
This depends on the battery you are charging as well as the battery's capacity. For example, an 18650 battery with a 3500mAh capacity will take longer than an 18650 battery with a 2600mAh capacity. These times we provide below are general charge time
What batteries should I use in my Fenix light?
Fenix flashlights are compatible with many different brands of batteries, but not all battery manufacturers make all battery types, and quality/safety varies by brand. Energizer: any Energizer AA or AAA battery works in a flashlight that takes AA/AAA
Are ARB-L18 and ARB-L2 batteries interchangeable?
The ARB-L18 series batteries are upgrades to the older ARB-L2 batteries and generally work with most Fenix models that use 18650 batteries. However, the ARB-L18 series are sometimes unable to be used in older Fenix models and the ARB-L2 series are so
Can 14500 lithium-ion batteries be used in most other AA devices?
Check the product listing of whichever item you're interested in to learn more about which batteries are compatible. The product listing will say if it's compatible with a 14500 lithium ion battery and/or an AA battery.
Can Fenix AA flashlights use Li/FeS2 batteries?
No, these batteries are not recommended in Fenix flashlights. Please check the battery chart located on the product page of the AA flashlight you're interested in to see which batteries are compatible with the flashlight.
Can Fenix chargers charge unprotected 18650 cells?
We can't recommend any of our chargers for an unprotected 18650 battery. All Fenix batteries are protected batteries, so that's all we recommend to our customers. It's a safety feature for a very powerful battery type. Fenix chargers will charge othe
Can I leave my rechargeable flashlight or battery plugged in all the time?
The answer to this question is both yes and no. We don't recommend keeping it plugged in, but all Fenix flashlights and Fenix batteries have protection circuits that should prevent any damage to the light or battery that could be caused by overchargi
Can I order an extra battery for the Fenix UC40UE?
Yes, the Fenix ARB-L1-2600 is compatible and will charge inside the Fenix UC40UE.
Can I purchase an extra battery for the TK65R?
We do not sell this battery as a standard retail item. Please contact our customer service team to check availability.
Can I safely use the batteries in my Fenix flashlight until they are fully drained?
This depends on the battery that your flashlight is compatible with. If your flashlight is compatible with disposable batteries such as alkaline or lithium, then you can drain the battery completely with no worries. For any lithium-ion battery or rec
Can a 16340 battery be used in place of a CR123A battery?
It depends on which Fenix flashlight you're using. It is important to remember that even if the 16340 and CR123 batteries are of similar size and shape, they are different from one another. Check the product listing of the flashlight you're intereste
Can my Fenix 18650 lithium-ion batteries be left in a below zero storage area for days at a time and still function when the light is needed?
Yes, Fenix 18650 lithium-ion batteries can be stored in temperatures as low as negative 4 degrees Fahrenheit without permanent damage, but freezing temperatures will temporarily reduce their performance. Cold temperatures increase the battery interna
Can the ARB-L18-3400 battery be charged inside the older Fenix UC30 with a USB cable?
Yes, the Fenix ARB-L18-3400 battery will charge while within the old Fenix UC30 via micro USB.
Do I need to purchase a battery charger for the Fenix PD25's or PD25R's rechargeable battery?
You do not need to purchase a battery charger for either the original PD25 or the newer PD25R. The PD25R includes an ARB-L16-700 rechargeable 16340 battery and can be charged via the flashlight's USB Type-C charging port. The PD25 (discontinued) come
Do the Fenix USB rechargeable batteries come with a charging cable?
No, the USB rechargeable batteries do not come with charging cables. However, you can purchase charging cables.
Do the batteries in my rechargeable flashlight have to be charged through the flashlight or can I use a battery charger?
If your light uses a 21700, 18650, or other standard type of battery you can charge the batteries that come inside your Fenix rechargeable flashlight through the flashlight or on a charger. You don't need to specifically charge them using the flashli
Do you sell rechargeable CR123A lithium batteries?
No, we do not sell rechargeable CR123A lithium batteries because they are not compatible with Fenix lights. You can find more information about which batteries your Fenix flashlight is compatible with by checking its product page or user manual. You
Do Fenix batteries (Ni-MH or lithium-ion) come fully charged?
Due to shipping rules for lithium-ion batteries, they will only have around a 30% charge when shipped. This charge level will likely be lower when you receive your light as the batteries will slowly drain while in storage. We recommend topping the ba
How can I tell if my battery is fully charged?
If you have a USB rechargeable lithium-ion battery, the indicator will glow solid blue once it's fully charged. If you have a Fenix battery charger with an LCD screen, the display will show you when the battery is full. If you have a Fenix battery ch
How can I tell when my Fenix USB rechargeable battery is fully charged?
On the micro USB rechargeable batteries, there will be a small LED on top of the battery. It will be red while it is charging and, once it is done, the red LED will be replaced by a blue LED.
How do I know when my battery is finished charging?
All Fenix products that charge batteries have a pretty clear way to tell when the battery is full! USB rechargeable batteries like the ARB-L18-3500U will light up blue with they are fully charged. Chargers that have an LCD screen display like the ARE
How long do Fenix batteries last?
All removable Fenix batteries carry a 1-year warranty that protects the purchaser from any battery failure in that time period. Batteries that are built-in (like those inside the BC30R or HL32R) are covered for 2 years. Even outside of the warranty p
How long do rechargeable lithium ion batteries last?
With proper upkeep, rechargeable lithium ion batteries should last for around 500 charge cycles. However, this can fluctuate depending on the type of climate and use.
How much longer would a Fenix flashlight run if I were to use an 18650 3500mAh battery vs an 18650 2600mAh battery?
The flashlight's runtime would increase about 30% if you were to use the 3500mAh Fenix 18650 battery rather than the 2600mAh Fenix 18650 battery.
How would you compare the performance of the Ni-MH 1.2V battery and the lithium 1.5V battery?
In most Fenix flashlights, runtime is comparable between the two despite the voltage difference, because Fenix lights are regulated to draw the current they need rather than depending directly on raw voltage - capacity (mAh) matters more than the sma
Is the Fenix ARB-L1-2600 battery a replacement for the ARB-L1T or ARB-L1S?
Yes, the ARB-L1-2600 is a replacement for both the ARB-L1T and ARB-L1S.
Is there a recommended storage voltage for 18650 rechargeable batteries?
When it comes to storing 18650 batteries, there are a few things to keep in mind. 18650 batteries drain with time so you'll want to recharge them about once a month to be sure they have a full charge when you need them. When you receive a Fenix batte
Is there a way to fix an overdischarged battery in deep discharge?
Sometimes putting an overdischarged battery in a charger can give it a "jump" and fix it, but this doesn't always work.
My Fenix battery is starting to peel and swell after charging. Is this normal?
No, this is not normal for any battery to do. please navigate to our Warranty and Repair page (https://fenix-store.com/pages/warranty-info) to find more information and submit your request for repair.
My unit's USB port is not working. Is it covered under warranty?
Yes, in the majority of cases a defective USB port would be covered under warranty. The only exception to this would be if you are responsible for the USB port breaking by incorrectly inserting the cable or by allowing it to be compromised by dust or
Should I discharge an 18650 battery before charging it?
We recommend that you NEVER fully discharge any lithium-ion batteries. By not fully discharging it, you help improve the battery life. If a lithium-ion battery is used until it is completely empty it can enter a state of deep-discharge which can prev
The plastic wrapping on my Fenix lithium-ion battery has started to tear. Is it still safe to use?
Any amount of tear in the plastic wrapping can make the battery unsafe. We recommend that you stop using the damaged battery and replace it.
What are the advantages and disadvantages of using a micro USB rechargeable lithium-ion battery versus a rechargeable lithium-ion battery that requires a battery charger?
One advantage of the micro USB rechargeable lithium-ion batteries is that you do not need to purchase a separate charger for these batteries. However, they are a little bit longer and don't work with all Fenix flashlights in some models. Also, the pr
What are the charging requirements for batteries with charging ports?
Fenix Direct Charge batteries need a controlled power source: use a single-port USB charger/adapter around 2A output, no more than 10W max. Most multi-port chargers or hubs (including computer USB ports) aren't recommended, since they can interfere w
What are the pros and cons of 18650 lithium-ion batteries?
18650 lithium-ion batteries will often provide you with more power and longer runtimes in the flashlight. They're also rechargeable which is a definite bonus. However, lithium-ion batteries do drain slowly over time and tend to be more costly than an
What batteries can be charged inside USB rechargeable flashlights?
Each flashlight can only charge the primary battery type it's designed for. A light that uses and comes with an 18650 battery will charge that 18650 - many of these lights can also run on CR123A batteries as a backup, but can't charge CR123A batterie
What does the mAh mean in lithium-ion batteries?
mAh stands for "milliamp-hour" - it's a measure of the battery's total energy capacity over time, not just current. The higher the mAh rating, the longer the runtime before you need to recharge. It's important to use the correct size battery for your
What is a protected battery?
Fenix protected batteries feature three levels of over heat protection as well as over discharge protection, over charge protection, and short circuit protection.
What is the difference between the Fenix ARB-L2M batteries and the ARB-L18 batteries?
The Fenix ARB-L18 series have replaced the ARB-L2M batteries which are now discontinued. The ARB-L18 batteries work with almost all Fenix flashlights that were compatible with the ARB-L2M batteries.
What's the difference between a $5 18650 battery and a Fenix battery?
Most low-priced batteries are NOT protected, we would caution you against using those. As you know, 18650 Lithium-Ion batteries are very powerful. Because of that, you should be aware of the safe handling of them. Don't look just at the price of the
When do I need to replace rechargeable lithium ion batteries?
There is no need to replace 18650 batteries after a set period of time. They can continue to be used until they stop working or until they no longer offer the runtimes that you need.
Where are Fenix brand flashlights manufactured?
Fenix is manufactured in China and Fenix Store is an Official Retailer/Distributor for them here in the United States.
Where can I purchase the Fenix ARB-L2 series batteries?
The Fenix ARB-L2 series has been discontinued and replaced with the ARB-L18 series, which comes in several capacities (e.g. ARB-L18-2600, ARB-L18-3400, ARB-L18-3500).
Which 18650 batteries replaced the ARB-L2 series?
The ARB-L2 series was replaced by the ARB-L18 series which you can find here.
Which battery is better for extremely cold weather: 18650 lithium-ion batteries or CR123A lithium batteries?
CR123A batteries generally perform better in extreme cold (and extreme heat) than 18650 lithium-ion batteries. 18650 batteries will still work in a range of about -4°F to 140°F, while CR123A batteries can typically operate from about -40°F to 158°F.
Who manufactures the Fenix lithium-ion batteries?
The manufacturer is Fenix themselves based in China. Each battery from Fenix has a multiple protection design to ensure safety. For instance, there is the protection circuit in the anode that will protect against over charge, over discharge, short ci
Will a 16340 make my CR123A light brighter?
This depends on the specific flashlight. Some Fenix flashlights are designed to be compatible with both CR123A and 16340 batteries, while older or specific models are not - always check your flashlight's user manual before trying a 16340 in a light d
Would a standard non-Fenix AA charger charge Fenix 14500 lithium-ion batteries?
This depends on the charger you are using. As long as the manual on your charger states that it can charge 14500 batteries, then the Fenix 14500 batteries should charge just fine.