Rechargeable Batteries | Fenix L4 26650 Battery

Fenix ARB-L4 26650 Rechargeable battery

Hello and thank you for joining me today. My name is Brad with the Fenix-Store and I will be going over the extremely powerful 26650 size batteries (26650 batteries discontinued). The name 26650 comes from the dimensions of the battery which is 26mm by 65mm and is classified as a Lithium-Ion rechargeable battery and is quite a bit larger than 18650 batteries and will have twice the volume. In some cases you can use 18650’s in a Fenix 26650 light with a sleeve or adapter, but not the other way round. I’ve heard of some Fenix 26650’s being 5000 mAH or higher but you have to wonder if that is really accurate. In my experience anything over 4500 or 4800 just isn’t true.

  Many of the first batteries were sealed in glass jars and over the years has evolved into the cylindrical shape you're familiar with today. Cylindrical cells have been and continue to be the most commonly used styles due to ease of manufacturing and their ability to tolerate high internal pressures with warping the battery. Most lithium and nickel cells include a positive thermal coefficient or PTC. When exposed to excessive current, the normally conductive polymer heats up and becomes resistive, stopping current flow and acting as short circuit protection. Once the short is removed, the PTC cools down and returns to the conductive state.

 Most cells also include some form of pressure relief that uses a membrane that will rupture under high pressure which can result in leakage and dry out the cell however, ones with re-sealable vents are the most preferred design. In some cells the relief valve is attached to an electrical fuse that will permanently open if any unsafe pressure is detected. The Fenix brand 26650 features three sets of protection, Pressure relief valve protection, separate microporous protection and PTC cathodal block protection which all protect against overheating, over charging and discharging as well as impacts to the battery. A properly maintained battery is designed to retain up to 70% of its original capacity at 500 charge and discharge cycles and should be replaced when it no longer holds sufficient storage. Here are the parameters for Fenix’s Li-ion 26650.

Image result for fenix L4-4800 specs


 Battery safety should be top priority when using any cell. Mistreated batteries can get extremely hot and/or vent which could cause injury. Always follow the following rules to keep yourself safe. You should never completely discharge batteries and charge fully to 4.2V before first use. Never use a lot of force to install the battery and only use high quality smart battery chargers. Exposing to extreme heat can damage the battery and make it not perform like it should. Do not connect the positive contact to the negative contact as that could short circuit the battery. Please make sure to stay within the limits of the specification and never exceed them. Always use protective cases for loose batteries.Try not to store your li-ion batteries fully charged for an extended period of time and if you do please do it in a case or individual box in cool, dry place. Always make sure you are using a smart charger specifically designed for Li-ion batteries.

 There are tons of uses for a 26650 battery, the most common uses of these style batteries are laptops, E-cigs, electric bikes, toys, power tools, high powered LED flashlights and even some medical instruments which make this battery very valuable in several areas. Over the years there has been rapid growth in the sales and in the benefits of lithium ion when compared to all the earlier rechargeable batteries and more than likely the lithium ion battery will continue to improve in cost, energy, safety and power capability and will be a fierce competitor for years to come.