Fenix Batteries
How big are Fenix 14500, 18650 and 21700 batteries?
Fenix 14500 batteries measure 14.5 x 50 mm, 18650 batteries 18.6 x 69-70 mm, and 21700 batteries 21.5 x 76 mm.
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. For the expected charge time, please check the manua
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
Can 14500 lithium-ion batteries be used in most other AA devices?
Only if the device says it accepts a 14500. A 14500 is AA-size but many run at about 3.6 V, while a standard AA is 1.5 V.
Can Fenix AA flashlights use Li/FeS2 batteries?
It depends on the model. Many Fenix AA flashlights list 1.5V lithium (Li/FeS2) AA batteries as compatible, but compatibility varies by light. Please check the battery table in your light's user manual or on the product page of the AA flashlight you'r
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 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 the light. A 16340 is a rechargeable 3.6 V battery and a CR123A is a non-rechargeable 3 V battery, so check your light's listing or manual first.
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?
Generally yes, but freezing temperatures will temporarily reduce their performance. Cold temperatures increase the battery internal resistance. This causes a temporary drop in voltage and available runtime while the battery is cold, meaning the flash
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 a rechargeable 16340 battery and can be charged via the flashlight's USB Type-C charging port. The PD25 (discontinued) comes with an ARB
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. The rechargeable lithium-ion battery in this size is the 16340 (Fenix ARB-L16 series), which can only be used in Fenix lights designed for it. You can find more information about which batteri
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 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 (sealed battery packs that cannot be removed from the light) are covered for 2 years. Even out
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 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 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 USB rechargeable lithium-ion battery versus a rechargeable lithium-ion battery that requires a battery charger?
One advantage of the USB rechargeable lithium-ion batteries (micro-USB or USB-C, depending on the model) 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 f
What are the charging requirements for batteries with charging ports?
Charging requirements vary by battery. Please check the user manual or product page for your specific battery for its recommended charging input and instructions, and use a standard USB power adapter. If you have questions about charging your battery
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 (milliamp-hour) is a battery's capacity. A higher mAh generally means a longer runtime, for example up to about 35% more from a 3,500 mAh 18650 than a 2,600 mAh one.
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'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 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 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. For the specific operating temperature range of a battery, please check its manual or product page.
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
Would a standard non-Fenix AA charger charge Fenix 14500 lithium-ion batteries?
It depends on the charger, so check its manual. The Fenix ARB-L14-1600U is the exception and charges only through its built-in USB port.
Do the Fenix ARB-L18-3400U and ARB-L18-3500U batteries work in my PD35 (original, V2.0 or V3.0)?
The ARB-L18-3400U and ARB-L18-3500U USB-rechargeable 18650s work in the PD35 V2.0 and PD35 V3.0, but not in the original PD35 (V1).